regulator: tps62361: make all register as non-volatile
[linux-2.6.git] / drivers / regulator / fixed.c
1 /*
2  * fixed.c
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * Copyright (c) 2009 Nokia Corporation
9  * Roger Quadros <ext-roger.quadros@nokia.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of the
14  * License, or (at your option) any later version.
15  *
16  * This is useful for systems with mixed controllable and
17  * non-controllable regulators, as well as for allowing testing on
18  * systems with no controllable regulators.
19  */
20
21 #include <linux/err.h>
22 #include <linux/mutex.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/regulator/driver.h>
26 #include <linux/regulator/fixed.h>
27 #include <linux/gpio.h>
28 #include <linux/delay.h>
29 #include <linux/slab.h>
30 #include <linux/of.h>
31 #include <linux/of_gpio.h>
32 #include <linux/regulator/of_regulator.h>
33 #include <linux/regulator/machine.h>
34
35 struct fixed_voltage_data {
36         struct regulator_desc desc;
37         struct regulator_dev *dev;
38         int microvolts;
39         int gpio;
40         unsigned startup_delay;
41         bool enable_high;
42         bool is_enabled;
43 };
44
45
46 /**
47  * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
48  * @dev: device requesting for fixed_voltage_config
49  *
50  * Populates fixed_voltage_config structure by extracting data from device
51  * tree node, returns a pointer to the populated structure of NULL if memory
52  * alloc fails.
53  */
54 static struct fixed_voltage_config *
55 of_get_fixed_voltage_config(struct device *dev)
56 {
57         struct fixed_voltage_config *config;
58         struct device_node *np = dev->of_node;
59         const __be32 *delay;
60         struct regulator_init_data *init_data;
61
62         config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
63                                                                  GFP_KERNEL);
64         if (!config)
65                 return NULL;
66
67         config->init_data = of_get_regulator_init_data(dev, dev->of_node);
68         if (!config->init_data)
69                 return NULL;
70
71         init_data = config->init_data;
72         init_data->constraints.apply_uV = 0;
73
74         config->supply_name = init_data->constraints.name;
75         if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
76                 config->microvolts = init_data->constraints.min_uV;
77         } else {
78                 dev_err(dev,
79                          "Fixed regulator specified with variable voltages\n");
80                 return NULL;
81         }
82
83         if (init_data->constraints.boot_on)
84                 config->enabled_at_boot = true;
85
86         config->gpio = of_get_named_gpio(np, "gpio", 0);
87         delay = of_get_property(np, "startup-delay-us", NULL);
88         if (delay)
89                 config->startup_delay = be32_to_cpu(*delay);
90
91         if (of_find_property(np, "enable-active-high", NULL))
92                 config->enable_high = true;
93
94         return config;
95 }
96
97 static int fixed_voltage_is_enabled(struct regulator_dev *dev)
98 {
99         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
100
101         return data->is_enabled;
102 }
103
104 static int fixed_voltage_enable(struct regulator_dev *dev)
105 {
106         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
107
108         if (gpio_is_valid(data->gpio)) {
109                 gpio_set_value_cansleep(data->gpio, data->enable_high);
110                 data->is_enabled = true;
111         }
112
113         return 0;
114 }
115
116 static int fixed_voltage_disable(struct regulator_dev *dev)
117 {
118         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
119
120         if (gpio_is_valid(data->gpio)) {
121                 gpio_set_value_cansleep(data->gpio, !data->enable_high);
122                 data->is_enabled = false;
123         }
124
125         return 0;
126 }
127
128 static int fixed_voltage_enable_time(struct regulator_dev *dev)
129 {
130         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
131
132         return data->startup_delay;
133 }
134
135 static int fixed_voltage_get_voltage(struct regulator_dev *dev)
136 {
137         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
138
139         if (data->microvolts)
140                 return data->microvolts;
141         else
142                 return -EINVAL;
143 }
144
145 static int fixed_voltage_list_voltage(struct regulator_dev *dev,
146                                       unsigned selector)
147 {
148         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
149
150         if (selector != 0)
151                 return -EINVAL;
152
153         return data->microvolts;
154 }
155
156 static struct regulator_ops fixed_voltage_ops = {
157         .is_enabled = fixed_voltage_is_enabled,
158         .enable = fixed_voltage_enable,
159         .disable = fixed_voltage_disable,
160         .enable_time = fixed_voltage_enable_time,
161         .get_voltage = fixed_voltage_get_voltage,
162         .list_voltage = fixed_voltage_list_voltage,
163 };
164
165 static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
166 {
167         struct fixed_voltage_config *config;
168         struct fixed_voltage_data *drvdata;
169         int ret;
170
171         if (pdev->dev.of_node)
172                 config = of_get_fixed_voltage_config(&pdev->dev);
173         else
174                 config = pdev->dev.platform_data;
175
176         if (!config)
177                 return -ENOMEM;
178
179         drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
180         if (drvdata == NULL) {
181                 dev_err(&pdev->dev, "Failed to allocate device data\n");
182                 ret = -ENOMEM;
183                 goto err;
184         }
185
186         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
187         if (drvdata->desc.name == NULL) {
188                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
189                 ret = -ENOMEM;
190                 goto err;
191         }
192         drvdata->desc.type = REGULATOR_VOLTAGE;
193         drvdata->desc.owner = THIS_MODULE;
194         drvdata->desc.ops = &fixed_voltage_ops;
195
196         if (config->microvolts)
197                 drvdata->desc.n_voltages = 1;
198
199         drvdata->microvolts = config->microvolts;
200         drvdata->gpio = config->gpio;
201         drvdata->startup_delay = config->startup_delay;
202
203         if (gpio_is_valid(config->gpio)) {
204                 int gpio_flag;
205                 drvdata->enable_high = config->enable_high;
206
207                 /* FIXME: Remove below print warning
208                  *
209                  * config->gpio must be set to -EINVAL by platform code if
210                  * GPIO control is not required. However, early adopters
211                  * not requiring GPIO control may forget to initialize
212                  * config->gpio to -EINVAL. This will cause GPIO 0 to be used
213                  * for GPIO control.
214                  *
215                  * This warning will be removed once there are a couple of users
216                  * for this driver.
217                  */
218                 if (!config->gpio)
219                         dev_warn(&pdev->dev,
220                                 "using GPIO 0 for regulator enable control\n");
221
222                 /*
223                  * set output direction without changing state
224                  * to prevent glitch
225                  */
226                 drvdata->is_enabled = config->enabled_at_boot;
227                 ret = drvdata->is_enabled ?
228                                 config->enable_high : !config->enable_high;
229                 gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
230
231                 if (config->gpio_is_open_drain)
232                         gpio_flag |= GPIOF_OPEN_DRAIN;
233
234                 ret = gpio_request_one(config->gpio, gpio_flag,
235                                                 config->supply_name);
236                 if (ret) {
237                         dev_err(&pdev->dev,
238                            "Could not obtain regulator enable GPIO %d: %d\n",
239                                                         config->gpio, ret);
240                         goto err_name;
241                 }
242
243         } else {
244                 /* Regulator without GPIO control is considered
245                  * always enabled
246                  */
247                 drvdata->is_enabled = true;
248         }
249
250         drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
251                                           config->init_data, drvdata,
252                                           pdev->dev.of_node);
253         if (IS_ERR(drvdata->dev)) {
254                 ret = PTR_ERR(drvdata->dev);
255                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
256                 goto err_gpio;
257         }
258
259         platform_set_drvdata(pdev, drvdata);
260
261         dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
262                 drvdata->microvolts);
263
264         return 0;
265
266 err_gpio:
267         if (gpio_is_valid(config->gpio))
268                 gpio_free(config->gpio);
269 err_name:
270         kfree(drvdata->desc.name);
271 err:
272         kfree(drvdata);
273         return ret;
274 }
275
276 static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
277 {
278         struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
279
280         regulator_unregister(drvdata->dev);
281         if (gpio_is_valid(drvdata->gpio))
282                 gpio_free(drvdata->gpio);
283         kfree(drvdata->desc.name);
284         kfree(drvdata);
285
286         return 0;
287 }
288
289 #if defined(CONFIG_OF)
290 static const struct of_device_id fixed_of_match[] __devinitconst = {
291         { .compatible = "regulator-fixed", },
292         {},
293 };
294 MODULE_DEVICE_TABLE(of, fixed_of_match);
295 #else
296 #define fixed_of_match NULL
297 #endif
298
299 static struct platform_driver regulator_fixed_voltage_driver = {
300         .probe          = reg_fixed_voltage_probe,
301         .remove         = __devexit_p(reg_fixed_voltage_remove),
302         .driver         = {
303                 .name           = "reg-fixed-voltage",
304                 .owner          = THIS_MODULE,
305                 .of_match_table = fixed_of_match,
306         },
307 };
308
309 static int __init regulator_fixed_voltage_init(void)
310 {
311         return platform_driver_register(&regulator_fixed_voltage_driver);
312 }
313 subsys_initcall(regulator_fixed_voltage_init);
314
315 static void __exit regulator_fixed_voltage_exit(void)
316 {
317         platform_driver_unregister(&regulator_fixed_voltage_driver);
318 }
319 module_exit(regulator_fixed_voltage_exit);
320
321 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
322 MODULE_DESCRIPTION("Fixed voltage regulator");
323 MODULE_LICENSE("GPL");
324 MODULE_ALIAS("platform:reg-fixed-voltage");