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