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