Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming
[pandora-kernel.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/slab.h>
34
35 struct gpio_regulator_data {
36         struct regulator_desc desc;
37         struct regulator_dev *dev;
38
39         struct gpio *gpios;
40         int nr_gpios;
41
42         struct gpio_regulator_state *states;
43         int nr_states;
44
45         int state;
46 };
47
48 static int gpio_regulator_get_value(struct regulator_dev *dev)
49 {
50         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
51         int ptr;
52
53         for (ptr = 0; ptr < data->nr_states; ptr++)
54                 if (data->states[ptr].gpios == data->state)
55                         return data->states[ptr].value;
56
57         return -EINVAL;
58 }
59
60 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
61                                         int min_uV, int max_uV,
62                                         unsigned *selector)
63 {
64         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
65         int ptr, target = 0, state, best_val = INT_MAX;
66
67         for (ptr = 0; ptr < data->nr_states; ptr++)
68                 if (data->states[ptr].value < best_val &&
69                     data->states[ptr].value >= min_uV &&
70                     data->states[ptr].value <= max_uV) {
71                         target = data->states[ptr].gpios;
72                         best_val = data->states[ptr].value;
73                         if (selector)
74                                 *selector = ptr;
75                 }
76
77         if (best_val == INT_MAX)
78                 return -EINVAL;
79
80         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
81                 state = (target & (1 << ptr)) >> ptr;
82                 gpio_set_value(data->gpios[ptr].gpio, state);
83         }
84         data->state = target;
85
86         return 0;
87 }
88
89 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
90                                       unsigned selector)
91 {
92         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
93
94         if (selector >= data->nr_states)
95                 return -EINVAL;
96
97         return data->states[selector].value;
98 }
99
100 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
101                                         int min_uA, int max_uA)
102 {
103         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
104         int ptr, target = 0, state, best_val = 0;
105
106         for (ptr = 0; ptr < data->nr_states; ptr++)
107                 if (data->states[ptr].value > best_val &&
108                     data->states[ptr].value >= min_uA &&
109                     data->states[ptr].value <= max_uA) {
110                         target = data->states[ptr].gpios;
111                         best_val = data->states[ptr].value;
112                 }
113
114         if (best_val == 0)
115                 return -EINVAL;
116
117         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
118                 state = (target & (1 << ptr)) >> ptr;
119                 gpio_set_value(data->gpios[ptr].gpio, state);
120         }
121         data->state = target;
122
123         return 0;
124 }
125
126 static struct regulator_ops gpio_regulator_voltage_ops = {
127         .get_voltage = gpio_regulator_get_value,
128         .set_voltage = gpio_regulator_set_voltage,
129         .list_voltage = gpio_regulator_list_voltage,
130 };
131
132 static struct regulator_ops gpio_regulator_current_ops = {
133         .get_current_limit = gpio_regulator_get_value,
134         .set_current_limit = gpio_regulator_set_current_limit,
135 };
136
137 static int __devinit gpio_regulator_probe(struct platform_device *pdev)
138 {
139         struct gpio_regulator_config *config = pdev->dev.platform_data;
140         struct gpio_regulator_data *drvdata;
141         struct regulator_config cfg = { };
142         int ptr, ret, state;
143
144         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
145                                GFP_KERNEL);
146         if (drvdata == NULL) {
147                 dev_err(&pdev->dev, "Failed to allocate device data\n");
148                 return -ENOMEM;
149         }
150
151         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
152         if (drvdata->desc.name == NULL) {
153                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
154                 ret = -ENOMEM;
155                 goto err;
156         }
157
158         drvdata->gpios = kmemdup(config->gpios,
159                                  config->nr_gpios * sizeof(struct gpio),
160                                  GFP_KERNEL);
161         if (drvdata->gpios == NULL) {
162                 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
163                 ret = -ENOMEM;
164                 goto err_name;
165         }
166
167         drvdata->states = kmemdup(config->states,
168                                   config->nr_states *
169                                          sizeof(struct gpio_regulator_state),
170                                   GFP_KERNEL);
171         if (drvdata->states == NULL) {
172                 dev_err(&pdev->dev, "Failed to allocate state data\n");
173                 ret = -ENOMEM;
174                 goto err_memgpio;
175         }
176         drvdata->nr_states = config->nr_states;
177
178         drvdata->desc.owner = THIS_MODULE;
179         drvdata->desc.enable_time = config->startup_delay;
180
181         /* handle regulator type*/
182         switch (config->type) {
183         case REGULATOR_VOLTAGE:
184                 drvdata->desc.type = REGULATOR_VOLTAGE;
185                 drvdata->desc.ops = &gpio_regulator_voltage_ops;
186                 drvdata->desc.n_voltages = config->nr_states;
187                 break;
188         case REGULATOR_CURRENT:
189                 drvdata->desc.type = REGULATOR_CURRENT;
190                 drvdata->desc.ops = &gpio_regulator_current_ops;
191                 break;
192         default:
193                 dev_err(&pdev->dev, "No regulator type set\n");
194                 ret = -EINVAL;
195                 goto err_memgpio;
196                 break;
197         }
198
199         drvdata->nr_gpios = config->nr_gpios;
200         ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
201         if (ret) {
202                 dev_err(&pdev->dev,
203                    "Could not obtain regulator setting GPIOs: %d\n", ret);
204                 goto err_memstate;
205         }
206
207         /* build initial state from gpio init data. */
208         state = 0;
209         for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
210                 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
211                         state |= (1 << ptr);
212         }
213         drvdata->state = state;
214
215         cfg.dev = &pdev->dev;
216         cfg.init_data = config->init_data;
217         cfg.driver_data = drvdata;
218
219         if (config->enable_gpio >= 0)
220                 cfg.ena_gpio = config->enable_gpio;
221         cfg.ena_gpio_invert = !config->enable_high;
222         if (config->enabled_at_boot) {
223                 if (config->enable_high)
224                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
225                 else
226                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
227         } else {
228                 if (config->enable_high)
229                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
230                 else
231                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
232         }
233
234         drvdata->dev = regulator_register(&drvdata->desc, &cfg);
235         if (IS_ERR(drvdata->dev)) {
236                 ret = PTR_ERR(drvdata->dev);
237                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
238                 goto err_stategpio;
239         }
240
241         platform_set_drvdata(pdev, drvdata);
242
243         return 0;
244
245 err_stategpio:
246         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
247 err_memstate:
248         kfree(drvdata->states);
249 err_memgpio:
250         kfree(drvdata->gpios);
251 err_name:
252         kfree(drvdata->desc.name);
253 err:
254         return ret;
255 }
256
257 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
258 {
259         struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
260
261         regulator_unregister(drvdata->dev);
262
263         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
264
265         kfree(drvdata->states);
266         kfree(drvdata->gpios);
267
268         kfree(drvdata->desc.name);
269
270         return 0;
271 }
272
273 static struct platform_driver gpio_regulator_driver = {
274         .probe          = gpio_regulator_probe,
275         .remove         = __devexit_p(gpio_regulator_remove),
276         .driver         = {
277                 .name           = "gpio-regulator",
278                 .owner          = THIS_MODULE,
279         },
280 };
281
282 static int __init gpio_regulator_init(void)
283 {
284         return platform_driver_register(&gpio_regulator_driver);
285 }
286 subsys_initcall(gpio_regulator_init);
287
288 static void __exit gpio_regulator_exit(void)
289 {
290         platform_driver_unregister(&gpio_regulator_driver);
291 }
292 module_exit(gpio_regulator_exit);
293
294 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
295 MODULE_DESCRIPTION("gpio voltage regulator");
296 MODULE_LICENSE("GPL");
297 MODULE_ALIAS("platform:gpio-regulator");