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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 <[email protected]>
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#include <linux/of.h>
17
18struct virtual_consumer_data {
19 struct mutex lock;
20 struct regulator *regulator;
21 bool enabled;
22 int min_uV;
23 int max_uV;
24 int min_uA;
25 int max_uA;
26 unsigned int mode;
27};
28
29static void update_voltage_constraints(struct device *dev,
30 struct virtual_consumer_data *data)
31{
32 int ret;
33
34 if (data->min_uV && data->max_uV
35 && data->min_uV <= data->max_uV) {
36 dev_dbg(dev, "Requesting %d-%duV\n",
37 data->min_uV, data->max_uV);
38 ret = regulator_set_voltage(data->regulator,
39 data->min_uV, data->max_uV);
40 if (ret != 0) {
41 dev_err(dev,
42 "regulator_set_voltage() failed: %d\n", ret);
43 return;
44 }
45 }
46
47 if (data->min_uV && data->max_uV && !data->enabled) {
48 dev_dbg(dev, "Enabling regulator\n");
49 ret = regulator_enable(data->regulator);
50 if (ret == 0)
51 data->enabled = true;
52 else
53 dev_err(dev, "regulator_enable() failed: %d\n",
54 ret);
55 }
56
57 if (!(data->min_uV && data->max_uV) && data->enabled) {
58 dev_dbg(dev, "Disabling regulator\n");
59 ret = regulator_disable(data->regulator);
60 if (ret == 0)
61 data->enabled = false;
62 else
63 dev_err(dev, "regulator_disable() failed: %d\n",
64 ret);
65 }
66}
67
68static void update_current_limit_constraints(struct device *dev,
69 struct virtual_consumer_data *data)
70{
71 int ret;
72
73 if (data->max_uA
74 && data->min_uA <= data->max_uA) {
75 dev_dbg(dev, "Requesting %d-%duA\n",
76 data->min_uA, data->max_uA);
77 ret = regulator_set_current_limit(data->regulator,
78 data->min_uA, data->max_uA);
79 if (ret != 0) {
80 dev_err(dev,
81 "regulator_set_current_limit() failed: %d\n",
82 ret);
83 return;
84 }
85 }
86
87 if (data->max_uA && !data->enabled) {
88 dev_dbg(dev, "Enabling regulator\n");
89 ret = regulator_enable(data->regulator);
90 if (ret == 0)
91 data->enabled = true;
92 else
93 dev_err(dev, "regulator_enable() failed: %d\n",
94 ret);
95 }
96
97 if (!(data->min_uA && data->max_uA) && data->enabled) {
98 dev_dbg(dev, "Disabling regulator\n");
99 ret = regulator_disable(data->regulator);
100 if (ret == 0)
101 data->enabled = false;
102 else
103 dev_err(dev, "regulator_disable() failed: %d\n",
104 ret);
105 }
106}
107
108static ssize_t show_min_uV(struct device *dev,
109 struct device_attribute *attr, char *buf)
110{
111 struct virtual_consumer_data *data = dev_get_drvdata(dev);
112 return sprintf(buf, "%d\n", data->min_uV);
113}
114
115static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
116 const char *buf, size_t count)
117{
118 struct virtual_consumer_data *data = dev_get_drvdata(dev);
119 long val;
120
121 if (kstrtol(buf, 10, &val) != 0)
122 return count;
123
124 mutex_lock(&data->lock);
125
126 data->min_uV = val;
127 update_voltage_constraints(dev, data);
128
129 mutex_unlock(&data->lock);
130
131 return count;
132}
133
134static ssize_t show_max_uV(struct device *dev,
135 struct device_attribute *attr, char *buf)
136{
137 struct virtual_consumer_data *data = dev_get_drvdata(dev);
138 return sprintf(buf, "%d\n", data->max_uV);
139}
140
141static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
142 const char *buf, size_t count)
143{
144 struct virtual_consumer_data *data = dev_get_drvdata(dev);
145 long val;
146
147 if (kstrtol(buf, 10, &val) != 0)
148 return count;
149
150 mutex_lock(&data->lock);
151
152 data->max_uV = val;
153 update_voltage_constraints(dev, data);
154
155 mutex_unlock(&data->lock);
156
157 return count;
158}
159
160static ssize_t show_min_uA(struct device *dev,
161 struct device_attribute *attr, char *buf)
162{
163 struct virtual_consumer_data *data = dev_get_drvdata(dev);
164 return sprintf(buf, "%d\n", data->min_uA);
165}
166
167static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
168 const char *buf, size_t count)
169{
170 struct virtual_consumer_data *data = dev_get_drvdata(dev);
171 long val;
172
173 if (kstrtol(buf, 10, &val) != 0)
174 return count;
175
176 mutex_lock(&data->lock);
177
178 data->min_uA = val;
179 update_current_limit_constraints(dev, data);
180
181 mutex_unlock(&data->lock);
182
183 return count;
184}
185
186static ssize_t show_max_uA(struct device *dev,
187 struct device_attribute *attr, char *buf)
188{
189 struct virtual_consumer_data *data = dev_get_drvdata(dev);
190 return sprintf(buf, "%d\n", data->max_uA);
191}
192
193static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
194 const char *buf, size_t count)
195{
196 struct virtual_consumer_data *data = dev_get_drvdata(dev);
197 long val;
198
199 if (kstrtol(buf, 10, &val) != 0)
200 return count;
201
202 mutex_lock(&data->lock);
203
204 data->max_uA = val;
205 update_current_limit_constraints(dev, data);
206
207 mutex_unlock(&data->lock);
208
209 return count;
210}
211
212static ssize_t show_mode(struct device *dev,
213 struct device_attribute *attr, char *buf)
214{
215 struct virtual_consumer_data *data = dev_get_drvdata(dev);
216
217 switch (data->mode) {
218 case REGULATOR_MODE_FAST:
219 return sprintf(buf, "fast\n");
220 case REGULATOR_MODE_NORMAL:
221 return sprintf(buf, "normal\n");
222 case REGULATOR_MODE_IDLE:
223 return sprintf(buf, "idle\n");
224 case REGULATOR_MODE_STANDBY:
225 return sprintf(buf, "standby\n");
226 default:
227 return sprintf(buf, "unknown\n");
228 }
229}
230
231static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
232 const char *buf, size_t count)
233{
234 struct virtual_consumer_data *data = dev_get_drvdata(dev);
235 unsigned int mode;
236 int ret;
237
238 /*
239 * sysfs_streq() doesn't need the \n's, but we add them so the strings
240 * will be shared with show_mode(), above.
241 */
242 if (sysfs_streq(buf, "fast\n"))
243 mode = REGULATOR_MODE_FAST;
244 else if (sysfs_streq(buf, "normal\n"))
245 mode = REGULATOR_MODE_NORMAL;
246 else if (sysfs_streq(buf, "idle\n"))
247 mode = REGULATOR_MODE_IDLE;
248 else if (sysfs_streq(buf, "standby\n"))
249 mode = REGULATOR_MODE_STANDBY;
250 else {
251 dev_err(dev, "Configuring invalid mode\n");
252 return count;
253 }
254
255 mutex_lock(&data->lock);
256 ret = regulator_set_mode(data->regulator, mode);
257 if (ret == 0)
258 data->mode = mode;
259 else
260 dev_err(dev, "Failed to configure mode: %d\n", ret);
261 mutex_unlock(&data->lock);
262
263 return count;
264}
265
266static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
267static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
268static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
269static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
270static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
271
272static struct attribute *regulator_virtual_attributes[] = {
273 &dev_attr_min_microvolts.attr,
274 &dev_attr_max_microvolts.attr,
275 &dev_attr_min_microamps.attr,
276 &dev_attr_max_microamps.attr,
277 &dev_attr_mode.attr,
278 NULL
279};
280
281static const struct attribute_group regulator_virtual_attr_group = {
282 .attrs = regulator_virtual_attributes,
283};
284
285#ifdef CONFIG_OF
286static const struct of_device_id regulator_virtual_consumer_of_match[] = {
287 { .compatible = "regulator-virtual-consumer" },
288 {},
289};
290MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match);
291#endif
292
293static int regulator_virtual_probe(struct platform_device *pdev)
294{
295 char *reg_id = dev_get_platdata(&pdev->dev);
296 struct virtual_consumer_data *drvdata;
297 static bool warned;
298 int ret;
299
300 if (!warned) {
301 warned = true;
302 pr_warn("**********************************************************\n");
303 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
304 pr_warn("** **\n");
305 pr_warn("** regulator-virtual-consumer is only for testing and **\n");
306 pr_warn("** debugging. Do not use it in a production kernel. **\n");
307 pr_warn("** **\n");
308 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
309 pr_warn("**********************************************************\n");
310 }
311
312 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
313 GFP_KERNEL);
314 if (drvdata == NULL)
315 return -ENOMEM;
316
317 /*
318 * This virtual consumer does not have any hardware-defined supply
319 * name, so just allow the regulator to be specified in a property
320 * named "default-supply" when we're being probed from devicetree.
321 */
322 if (!reg_id && pdev->dev.of_node)
323 reg_id = "default";
324
325 mutex_init(&drvdata->lock);
326
327 drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
328 if (IS_ERR(drvdata->regulator))
329 return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->regulator),
330 "Failed to obtain supply '%s'\n",
331 reg_id);
332
333 ret = sysfs_create_group(&pdev->dev.kobj,
334 &regulator_virtual_attr_group);
335 if (ret != 0) {
336 dev_err(&pdev->dev,
337 "Failed to create attribute group: %d\n", ret);
338 return ret;
339 }
340
341 drvdata->mode = regulator_get_mode(drvdata->regulator);
342
343 platform_set_drvdata(pdev, drvdata);
344
345 return 0;
346}
347
348static void regulator_virtual_remove(struct platform_device *pdev)
349{
350 struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
351
352 sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
353
354 if (drvdata->enabled)
355 regulator_disable(drvdata->regulator);
356}
357
358static struct platform_driver regulator_virtual_consumer_driver = {
359 .probe = regulator_virtual_probe,
360 .remove = regulator_virtual_remove,
361 .driver = {
362 .name = "reg-virt-consumer",
363 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
364 .of_match_table = of_match_ptr(regulator_virtual_consumer_of_match),
365 },
366};
367
368module_platform_driver(regulator_virtual_consumer_driver);
369
370MODULE_AUTHOR("Mark Brown <[email protected]>");
371MODULE_DESCRIPTION("Virtual regulator consumer");
372MODULE_LICENSE("GPL");
373MODULE_ALIAS("platform:reg-virt-consumer");