Regulators: virtual - use sysfs attribute groups
[linux-2.6.git] / drivers / regulator / virtual.c
1 /*
2  * reg-virtual-consumer.c
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  */
13
14 #include <linux/err.h>
15 #include <linux/mutex.h>
16 #include <linux/platform_device.h>
17 #include <linux/regulator/consumer.h>
18
19 struct virtual_consumer_data {
20         struct mutex lock;
21         struct regulator *regulator;
22         bool enabled;
23         int min_uV;
24         int max_uV;
25         int min_uA;
26         int max_uA;
27         unsigned int mode;
28 };
29
30 static void update_voltage_constraints(struct device *dev,
31                                        struct virtual_consumer_data *data)
32 {
33         int ret;
34
35         if (data->min_uV && data->max_uV
36             && data->min_uV <= data->max_uV) {
37                 dev_dbg(dev, "Requesting %d-%duV\n",
38                         data->min_uV, data->max_uV);
39                 ret = regulator_set_voltage(data->regulator,
40                                         data->min_uV, data->max_uV);
41                 if (ret != 0) {
42                         dev_err(dev,
43                                 "regulator_set_voltage() failed: %d\n", ret);
44                         return;
45                 }
46         }
47
48         if (data->min_uV && data->max_uV && !data->enabled) {
49                 dev_dbg(dev, "Enabling regulator\n");
50                 ret = regulator_enable(data->regulator);
51                 if (ret == 0)
52                         data->enabled = true;
53                 else
54                         dev_err(dev, "regulator_enable() failed: %d\n",
55                                 ret);
56         }
57
58         if (!(data->min_uV && data->max_uV) && data->enabled) {
59                 dev_dbg(dev, "Disabling regulator\n");
60                 ret = regulator_disable(data->regulator);
61                 if (ret == 0)
62                         data->enabled = false;
63                 else
64                         dev_err(dev, "regulator_disable() failed: %d\n",
65                                 ret);
66         }
67 }
68
69 static void update_current_limit_constraints(struct device *dev,
70                                           struct virtual_consumer_data *data)
71 {
72         int ret;
73
74         if (data->max_uA
75             && data->min_uA <= data->max_uA) {
76                 dev_dbg(dev, "Requesting %d-%duA\n",
77                         data->min_uA, data->max_uA);
78                 ret = regulator_set_current_limit(data->regulator,
79                                         data->min_uA, data->max_uA);
80                 if (ret != 0) {
81                         dev_err(dev,
82                                 "regulator_set_current_limit() failed: %d\n",
83                                 ret);
84                         return;
85                 }
86         }
87
88         if (data->max_uA && !data->enabled) {
89                 dev_dbg(dev, "Enabling regulator\n");
90                 ret = regulator_enable(data->regulator);
91                 if (ret == 0)
92                         data->enabled = true;
93                 else
94                         dev_err(dev, "regulator_enable() failed: %d\n",
95                                 ret);
96         }
97
98         if (!(data->min_uA && data->max_uA) && data->enabled) {
99                 dev_dbg(dev, "Disabling regulator\n");
100                 ret = regulator_disable(data->regulator);
101                 if (ret == 0)
102                         data->enabled = false;
103                 else
104                         dev_err(dev, "regulator_disable() failed: %d\n",
105                                 ret);
106         }
107 }
108
109 static ssize_t show_min_uV(struct device *dev,
110                            struct device_attribute *attr, char *buf)
111 {
112         struct virtual_consumer_data *data = dev_get_drvdata(dev);
113         return sprintf(buf, "%d\n", data->min_uV);
114 }
115
116 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
117                           const char *buf, size_t count)
118 {
119         struct virtual_consumer_data *data = dev_get_drvdata(dev);
120         long val;
121
122         if (strict_strtol(buf, 10, &val) != 0)
123                 return count;
124
125         mutex_lock(&data->lock);
126
127         data->min_uV = val;
128         update_voltage_constraints(dev, data);
129
130         mutex_unlock(&data->lock);
131
132         return count;
133 }
134
135 static ssize_t show_max_uV(struct device *dev,
136                            struct device_attribute *attr, char *buf)
137 {
138         struct virtual_consumer_data *data = dev_get_drvdata(dev);
139         return sprintf(buf, "%d\n", data->max_uV);
140 }
141
142 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
143                           const char *buf, size_t count)
144 {
145         struct virtual_consumer_data *data = dev_get_drvdata(dev);
146         long val;
147
148         if (strict_strtol(buf, 10, &val) != 0)
149                 return count;
150
151         mutex_lock(&data->lock);
152
153         data->max_uV = val;
154         update_voltage_constraints(dev, data);
155
156         mutex_unlock(&data->lock);
157
158         return count;
159 }
160
161 static ssize_t show_min_uA(struct device *dev,
162                            struct device_attribute *attr, char *buf)
163 {
164         struct virtual_consumer_data *data = dev_get_drvdata(dev);
165         return sprintf(buf, "%d\n", data->min_uA);
166 }
167
168 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
169                           const char *buf, size_t count)
170 {
171         struct virtual_consumer_data *data = dev_get_drvdata(dev);
172         long val;
173
174         if (strict_strtol(buf, 10, &val) != 0)
175                 return count;
176
177         mutex_lock(&data->lock);
178
179         data->min_uA = val;
180         update_current_limit_constraints(dev, data);
181
182         mutex_unlock(&data->lock);
183
184         return count;
185 }
186
187 static ssize_t show_max_uA(struct device *dev,
188                            struct device_attribute *attr, char *buf)
189 {
190         struct virtual_consumer_data *data = dev_get_drvdata(dev);
191         return sprintf(buf, "%d\n", data->max_uA);
192 }
193
194 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
195                           const char *buf, size_t count)
196 {
197         struct virtual_consumer_data *data = dev_get_drvdata(dev);
198         long val;
199
200         if (strict_strtol(buf, 10, &val) != 0)
201                 return count;
202
203         mutex_lock(&data->lock);
204
205         data->max_uA = val;
206         update_current_limit_constraints(dev, data);
207
208         mutex_unlock(&data->lock);
209
210         return count;
211 }
212
213 static ssize_t show_mode(struct device *dev,
214                          struct device_attribute *attr, char *buf)
215 {
216         struct virtual_consumer_data *data = dev_get_drvdata(dev);
217
218         switch (data->mode) {
219         case REGULATOR_MODE_FAST:
220                 return sprintf(buf, "fast\n");
221         case REGULATOR_MODE_NORMAL:
222                 return sprintf(buf, "normal\n");
223         case REGULATOR_MODE_IDLE:
224                 return sprintf(buf, "idle\n");
225         case REGULATOR_MODE_STANDBY:
226                 return sprintf(buf, "standby\n");
227         default:
228                 return sprintf(buf, "unknown\n");
229         }
230 }
231
232 static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
233                         const char *buf, size_t count)
234 {
235         struct virtual_consumer_data *data = dev_get_drvdata(dev);
236         unsigned int mode;
237         int ret;
238
239         /*
240          * sysfs_streq() doesn't need the \n's, but we add them so the strings
241          * will be shared with show_mode(), above.
242          */
243         if (sysfs_streq(buf, "fast\n"))
244                 mode = REGULATOR_MODE_FAST;
245         else if (sysfs_streq(buf, "normal\n"))
246                 mode = REGULATOR_MODE_NORMAL;
247         else if (sysfs_streq(buf, "idle\n"))
248                 mode = REGULATOR_MODE_IDLE;
249         else if (sysfs_streq(buf, "standby\n"))
250                 mode = REGULATOR_MODE_STANDBY;
251         else {
252                 dev_err(dev, "Configuring invalid mode\n");
253                 return count;
254         }
255
256         mutex_lock(&data->lock);
257         ret = regulator_set_mode(data->regulator, mode);
258         if (ret == 0)
259                 data->mode = mode;
260         else
261                 dev_err(dev, "Failed to configure mode: %d\n", ret);
262         mutex_unlock(&data->lock);
263
264         return count;
265 }
266
267 static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
268 static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
269 static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
270 static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
271 static DEVICE_ATTR(mode, 0666, show_mode, set_mode);
272
273 static struct attribute *regulator_virtual_attributes[] = {
274         &dev_attr_min_microvolts.attr,
275         &dev_attr_max_microvolts.attr,
276         &dev_attr_min_microamps.attr,
277         &dev_attr_max_microamps.attr,
278         &dev_attr_mode.attr,
279         NULL
280 };
281
282 static const struct attribute_group regulator_virtual_attr_group = {
283         .attrs  = regulator_virtual_attributes,
284 };
285
286 static int __devinit regulator_virtual_probe(struct platform_device *pdev)
287 {
288         char *reg_id = pdev->dev.platform_data;
289         struct virtual_consumer_data *drvdata;
290         int ret;
291
292         drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL);
293         if (drvdata == NULL)
294                 return -ENOMEM;
295
296         mutex_init(&drvdata->lock);
297
298         drvdata->regulator = regulator_get(&pdev->dev, reg_id);
299         if (IS_ERR(drvdata->regulator)) {
300                 ret = PTR_ERR(drvdata->regulator);
301                 dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
302                         reg_id, ret);
303                 goto err;
304         }
305
306         ret = sysfs_create_group(&pdev->dev.kobj,
307                                  &regulator_virtual_attr_group);
308         if (ret != 0) {
309                 dev_err(&pdev->dev,
310                         "Failed to create attribute group: %d\n", ret);
311                 goto err_regulator;
312         }
313
314         drvdata->mode = regulator_get_mode(drvdata->regulator);
315
316         platform_set_drvdata(pdev, drvdata);
317
318         return 0;
319
320 err_regulator:
321         regulator_put(drvdata->regulator);
322 err:
323         kfree(drvdata);
324         return ret;
325 }
326
327 static int __devexit regulator_virtual_remove(struct platform_device *pdev)
328 {
329         struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
330
331         sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
332
333         if (drvdata->enabled)
334                 regulator_disable(drvdata->regulator);
335         regulator_put(drvdata->regulator);
336
337         kfree(drvdata);
338
339         platform_set_drvdata(pdev, NULL);
340
341         return 0;
342 }
343
344 static struct platform_driver regulator_virtual_consumer_driver = {
345         .probe          = regulator_virtual_probe,
346         .remove         = __devexit_p(regulator_virtual_remove),
347         .driver         = {
348                 .name           = "reg-virt-consumer",
349                 .owner          = THIS_MODULE,
350         },
351 };
352
353 static int __init regulator_virtual_consumer_init(void)
354 {
355         return platform_driver_register(&regulator_virtual_consumer_driver);
356 }
357 module_init(regulator_virtual_consumer_init);
358
359 static void __exit regulator_virtual_consumer_exit(void)
360 {
361         platform_driver_unregister(&regulator_virtual_consumer_driver);
362 }
363 module_exit(regulator_virtual_consumer_exit);
364
365 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
366 MODULE_DESCRIPTION("Virtual regulator consumer");
367 MODULE_LICENSE("GPL");
368 MODULE_ALIAS("platform:reg-virt-consumer");