regulator: tps62361: make all register as non-volatile
[linux-2.6.git] / drivers / regulator / gpio-regulator.c
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/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>
35
36 struct gpio_regulator_data {
37         struct regulator_desc desc;
38         struct regulator_dev *dev;
39
40         int enable_gpio;
41         bool enable_high;
42         bool is_enabled;
43         unsigned startup_delay;
44
45         struct gpio *gpios;
46         int nr_gpios;
47
48         struct gpio_regulator_state *states;
49         int nr_states;
50
51         int state;
52 };
53
54 static int gpio_regulator_is_enabled(struct regulator_dev *dev)
55 {
56         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
57
58         return data->is_enabled;
59 }
60
61 static int gpio_regulator_enable(struct regulator_dev *dev)
62 {
63         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
64
65         if (gpio_is_valid(data->enable_gpio)) {
66                 gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
67                 data->is_enabled = true;
68         }
69
70         return 0;
71 }
72
73 static int gpio_regulator_disable(struct regulator_dev *dev)
74 {
75         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
76
77         if (gpio_is_valid(data->enable_gpio)) {
78                 gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
79                 data->is_enabled = false;
80         }
81
82         return 0;
83 }
84
85 static int gpio_regulator_enable_time(struct regulator_dev *dev)
86 {
87         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
88
89         return data->startup_delay;
90 }
91
92 static int gpio_regulator_get_value(struct regulator_dev *dev)
93 {
94         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
95         int ptr;
96
97         for (ptr = 0; ptr < data->nr_states; ptr++)
98                 if (data->states[ptr].gpios == data->state)
99                         return data->states[ptr].value;
100
101         return -EINVAL;
102 }
103
104 static int gpio_regulator_set_value(struct regulator_dev *dev,
105                                         int min, int max)
106 {
107         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
108         int ptr, target, state;
109
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;
115
116         if (target < 0)
117                 return -EINVAL;
118
119         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
120                 state = (target & (1 << ptr)) >> ptr;
121                 gpio_set_value(data->gpios[ptr].gpio, state);
122         }
123         data->state = target;
124
125         return 0;
126 }
127
128 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
129                                         int min_uV, int max_uV,
130                                         unsigned *selector)
131 {
132         return gpio_regulator_set_value(dev, min_uV, max_uV);
133 }
134
135 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
136                                       unsigned selector)
137 {
138         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
139
140         if (selector >= data->nr_states)
141                 return -EINVAL;
142
143         return data->states[selector].value;
144 }
145
146 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
147                                         int min_uA, int max_uA)
148 {
149         return gpio_regulator_set_value(dev, min_uA, max_uA);
150 }
151
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,
160 };
161
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,
169 };
170
171 static int __devinit gpio_regulator_probe(struct platform_device *pdev)
172 {
173         struct gpio_regulator_config *config = pdev->dev.platform_data;
174         struct gpio_regulator_data *drvdata;
175         int ptr, ret, state;
176
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;
181         }
182
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;
188         }
189
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;
197         }
198
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;
207         }
208         drvdata->nr_states = config->nr_states;
209
210         drvdata->desc.owner = THIS_MODULE;
211
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;
228         }
229
230         drvdata->enable_gpio = config->enable_gpio;
231         drvdata->startup_delay = config->startup_delay;
232
233         if (gpio_is_valid(config->enable_gpio)) {
234                 drvdata->enable_high = config->enable_high;
235
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;
242                 }
243
244                 /* set output direction without changing state
245                  * to prevent glitch
246                  */
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);
255                 }
256
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;
262                 }
263         } else {
264                 /* Regulator without GPIO control is considered
265                  * always enabled
266                  */
267                 drvdata->is_enabled = true;
268         }
269
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;
276         }
277
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);
283         }
284         drvdata->state = state;
285
286         drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
287                                           config->init_data, drvdata, NULL);
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;
292         }
293
294         platform_set_drvdata(pdev, drvdata);
295
296         return 0;
297
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;
312 }
313
314 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
315 {
316         struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
317
318         regulator_unregister(drvdata->dev);
319
320         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
321
322         kfree(drvdata->states);
323         kfree(drvdata->gpios);
324
325         if (gpio_is_valid(drvdata->enable_gpio))
326                 gpio_free(drvdata->enable_gpio);
327
328         kfree(drvdata->desc.name);
329         kfree(drvdata);
330
331         return 0;
332 }
333
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,
340         },
341 };
342
343 static int __init gpio_regulator_init(void)
344 {
345         return platform_driver_register(&gpio_regulator_driver);
346 }
347 subsys_initcall(gpio_regulator_init);
348
349 static void __exit gpio_regulator_exit(void)
350 {
351         platform_driver_unregister(&gpio_regulator_driver);
352 }
353 module_exit(gpio_regulator_exit);
354
355 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
356 MODULE_DESCRIPTION("gpio voltage regulator");
357 MODULE_LICENSE("GPL");
358 MODULE_ALIAS("platform:gpio-regulator");