GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / regulator / virtual.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * reg-virtual-consumer.c
4  *
5  * Copyright 2008 Wolfson Microelectronics PLC.
6  *
7  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8  */
9
10 #include <linux/err.h>
11 #include <linux/mutex.h>
12 #include <linux/platform_device.h>
13 #include <linux/regulator/consumer.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16
17 struct virtual_consumer_data {
18         struct mutex lock;
19         struct regulator *regulator;
20         bool enabled;
21         int min_uV;
22         int max_uV;
23         int min_uA;
24         int max_uA;
25         unsigned int mode;
26 };
27
28 static void update_voltage_constraints(struct device *dev,
29                                        struct virtual_consumer_data *data)
30 {
31         int ret;
32
33         if (data->min_uV && data->max_uV
34             && data->min_uV <= data->max_uV) {
35                 dev_dbg(dev, "Requesting %d-%duV\n",
36                         data->min_uV, data->max_uV);
37                 ret = regulator_set_voltage(data->regulator,
38                                         data->min_uV, data->max_uV);
39                 if (ret != 0) {
40                         dev_err(dev,
41                                 "regulator_set_voltage() failed: %d\n", ret);
42                         return;
43                 }
44         }
45
46         if (data->min_uV && data->max_uV && !data->enabled) {
47                 dev_dbg(dev, "Enabling regulator\n");
48                 ret = regulator_enable(data->regulator);
49                 if (ret == 0)
50                         data->enabled = true;
51                 else
52                         dev_err(dev, "regulator_enable() failed: %d\n",
53                                 ret);
54         }
55
56         if (!(data->min_uV && data->max_uV) && data->enabled) {
57                 dev_dbg(dev, "Disabling regulator\n");
58                 ret = regulator_disable(data->regulator);
59                 if (ret == 0)
60                         data->enabled = false;
61                 else
62                         dev_err(dev, "regulator_disable() failed: %d\n",
63                                 ret);
64         }
65 }
66
67 static void update_current_limit_constraints(struct device *dev,
68                                           struct virtual_consumer_data *data)
69 {
70         int ret;
71
72         if (data->max_uA
73             && data->min_uA <= data->max_uA) {
74                 dev_dbg(dev, "Requesting %d-%duA\n",
75                         data->min_uA, data->max_uA);
76                 ret = regulator_set_current_limit(data->regulator,
77                                         data->min_uA, data->max_uA);
78                 if (ret != 0) {
79                         dev_err(dev,
80                                 "regulator_set_current_limit() failed: %d\n",
81                                 ret);
82                         return;
83                 }
84         }
85
86         if (data->max_uA && !data->enabled) {
87                 dev_dbg(dev, "Enabling regulator\n");
88                 ret = regulator_enable(data->regulator);
89                 if (ret == 0)
90                         data->enabled = true;
91                 else
92                         dev_err(dev, "regulator_enable() failed: %d\n",
93                                 ret);
94         }
95
96         if (!(data->min_uA && data->max_uA) && data->enabled) {
97                 dev_dbg(dev, "Disabling regulator\n");
98                 ret = regulator_disable(data->regulator);
99                 if (ret == 0)
100                         data->enabled = false;
101                 else
102                         dev_err(dev, "regulator_disable() failed: %d\n",
103                                 ret);
104         }
105 }
106
107 static ssize_t show_min_uV(struct device *dev,
108                            struct device_attribute *attr, char *buf)
109 {
110         struct virtual_consumer_data *data = dev_get_drvdata(dev);
111         return sprintf(buf, "%d\n", data->min_uV);
112 }
113
114 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
115                           const char *buf, size_t count)
116 {
117         struct virtual_consumer_data *data = dev_get_drvdata(dev);
118         long val;
119
120         if (kstrtol(buf, 10, &val) != 0)
121                 return count;
122
123         mutex_lock(&data->lock);
124
125         data->min_uV = val;
126         update_voltage_constraints(dev, data);
127
128         mutex_unlock(&data->lock);
129
130         return count;
131 }
132
133 static ssize_t show_max_uV(struct device *dev,
134                            struct device_attribute *attr, char *buf)
135 {
136         struct virtual_consumer_data *data = dev_get_drvdata(dev);
137         return sprintf(buf, "%d\n", data->max_uV);
138 }
139
140 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
141                           const char *buf, size_t count)
142 {
143         struct virtual_consumer_data *data = dev_get_drvdata(dev);
144         long val;
145
146         if (kstrtol(buf, 10, &val) != 0)
147                 return count;
148
149         mutex_lock(&data->lock);
150
151         data->max_uV = val;
152         update_voltage_constraints(dev, data);
153
154         mutex_unlock(&data->lock);
155
156         return count;
157 }
158
159 static ssize_t show_min_uA(struct device *dev,
160                            struct device_attribute *attr, char *buf)
161 {
162         struct virtual_consumer_data *data = dev_get_drvdata(dev);
163         return sprintf(buf, "%d\n", data->min_uA);
164 }
165
166 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
167                           const char *buf, size_t count)
168 {
169         struct virtual_consumer_data *data = dev_get_drvdata(dev);
170         long val;
171
172         if (kstrtol(buf, 10, &val) != 0)
173                 return count;
174
175         mutex_lock(&data->lock);
176
177         data->min_uA = val;
178         update_current_limit_constraints(dev, data);
179
180         mutex_unlock(&data->lock);
181
182         return count;
183 }
184
185 static ssize_t show_max_uA(struct device *dev,
186                            struct device_attribute *attr, char *buf)
187 {
188         struct virtual_consumer_data *data = dev_get_drvdata(dev);
189         return sprintf(buf, "%d\n", data->max_uA);
190 }
191
192 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
193                           const char *buf, size_t count)
194 {
195         struct virtual_consumer_data *data = dev_get_drvdata(dev);
196         long val;
197
198         if (kstrtol(buf, 10, &val) != 0)
199                 return count;
200
201         mutex_lock(&data->lock);
202
203         data->max_uA = val;
204         update_current_limit_constraints(dev, data);
205
206         mutex_unlock(&data->lock);
207
208         return count;
209 }
210
211 static ssize_t show_mode(struct device *dev,
212                          struct device_attribute *attr, char *buf)
213 {
214         struct virtual_consumer_data *data = dev_get_drvdata(dev);
215
216         switch (data->mode) {
217         case REGULATOR_MODE_FAST:
218                 return sprintf(buf, "fast\n");
219         case REGULATOR_MODE_NORMAL:
220                 return sprintf(buf, "normal\n");
221         case REGULATOR_MODE_IDLE:
222                 return sprintf(buf, "idle\n");
223         case REGULATOR_MODE_STANDBY:
224                 return sprintf(buf, "standby\n");
225         default:
226                 return sprintf(buf, "unknown\n");
227         }
228 }
229
230 static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
231                         const char *buf, size_t count)
232 {
233         struct virtual_consumer_data *data = dev_get_drvdata(dev);
234         unsigned int mode;
235         int ret;
236
237         /*
238          * sysfs_streq() doesn't need the \n's, but we add them so the strings
239          * will be shared with show_mode(), above.
240          */
241         if (sysfs_streq(buf, "fast\n"))
242                 mode = REGULATOR_MODE_FAST;
243         else if (sysfs_streq(buf, "normal\n"))
244                 mode = REGULATOR_MODE_NORMAL;
245         else if (sysfs_streq(buf, "idle\n"))
246                 mode = REGULATOR_MODE_IDLE;
247         else if (sysfs_streq(buf, "standby\n"))
248                 mode = REGULATOR_MODE_STANDBY;
249         else {
250                 dev_err(dev, "Configuring invalid mode\n");
251                 return count;
252         }
253
254         mutex_lock(&data->lock);
255         ret = regulator_set_mode(data->regulator, mode);
256         if (ret == 0)
257                 data->mode = mode;
258         else
259                 dev_err(dev, "Failed to configure mode: %d\n", ret);
260         mutex_unlock(&data->lock);
261
262         return count;
263 }
264
265 static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
266 static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
267 static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
268 static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
269 static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
270
271 static struct attribute *regulator_virtual_attributes[] = {
272         &dev_attr_min_microvolts.attr,
273         &dev_attr_max_microvolts.attr,
274         &dev_attr_min_microamps.attr,
275         &dev_attr_max_microamps.attr,
276         &dev_attr_mode.attr,
277         NULL
278 };
279
280 static const struct attribute_group regulator_virtual_attr_group = {
281         .attrs  = regulator_virtual_attributes,
282 };
283
284 static int regulator_virtual_probe(struct platform_device *pdev)
285 {
286         char *reg_id = dev_get_platdata(&pdev->dev);
287         struct virtual_consumer_data *drvdata;
288         int ret;
289
290         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
291                                GFP_KERNEL);
292         if (drvdata == NULL)
293                 return -ENOMEM;
294
295         mutex_init(&drvdata->lock);
296
297         drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
298         if (IS_ERR(drvdata->regulator)) {
299                 ret = PTR_ERR(drvdata->regulator);
300                 dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
301                         reg_id, ret);
302                 return ret;
303         }
304
305         ret = sysfs_create_group(&pdev->dev.kobj,
306                                  &regulator_virtual_attr_group);
307         if (ret != 0) {
308                 dev_err(&pdev->dev,
309                         "Failed to create attribute group: %d\n", ret);
310                 return ret;
311         }
312
313         drvdata->mode = regulator_get_mode(drvdata->regulator);
314
315         platform_set_drvdata(pdev, drvdata);
316
317         return 0;
318 }
319
320 static int regulator_virtual_remove(struct platform_device *pdev)
321 {
322         struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
323
324         sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
325
326         if (drvdata->enabled)
327                 regulator_disable(drvdata->regulator);
328
329         return 0;
330 }
331
332 static struct platform_driver regulator_virtual_consumer_driver = {
333         .probe          = regulator_virtual_probe,
334         .remove         = regulator_virtual_remove,
335         .driver         = {
336                 .name           = "reg-virt-consumer",
337         },
338 };
339
340 module_platform_driver(regulator_virtual_consumer_driver);
341
342 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
343 MODULE_DESCRIPTION("Virtual regulator consumer");
344 MODULE_LICENSE("GPL");
345 MODULE_ALIAS("platform:reg-virt-consumer");