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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
17struct 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
28static 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
67static 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
107static 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
114static 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
133static 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
140static 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
159static 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
166static 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
185static 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
192static 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
211static 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
230static 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
239
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
265static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
266static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
267static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
268static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
269static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
270
271static 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
280static const struct attribute_group regulator_virtual_attr_group = {
281 .attrs = regulator_virtual_attributes,
282};
283
284static 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 ®ulator_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
320static 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, ®ulator_virtual_attr_group);
325
326 if (drvdata->enabled)
327 regulator_disable(drvdata->regulator);
328
329 return 0;
330}
331
332static 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
340module_platform_driver(regulator_virtual_consumer_driver);
341
342MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
343MODULE_DESCRIPTION("Virtual regulator consumer");
344MODULE_LICENSE("GPL");
345MODULE_ALIAS("platform:reg-virt-consumer");
346
