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 | #include <linux/of.h> |
17 | |
18 | struct 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 | |
29 | static 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(regulator: data->regulator, |
39 | min_uV: data->min_uV, max_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(regulator: 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(regulator: 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 | |
68 | static 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(regulator: data->regulator, |
78 | min_uA: data->min_uA, max_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(regulator: 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(regulator: 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 | |
108 | static 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, fmt: "%d\n" , data->min_uV); |
113 | } |
114 | |
115 | static 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(s: buf, base: 10, res: &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(lock: &data->lock); |
130 | |
131 | return count; |
132 | } |
133 | |
134 | static 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, fmt: "%d\n" , data->max_uV); |
139 | } |
140 | |
141 | static 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(s: buf, base: 10, res: &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(lock: &data->lock); |
156 | |
157 | return count; |
158 | } |
159 | |
160 | static 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, fmt: "%d\n" , data->min_uA); |
165 | } |
166 | |
167 | static 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(s: buf, base: 10, res: &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(lock: &data->lock); |
182 | |
183 | return count; |
184 | } |
185 | |
186 | static 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, fmt: "%d\n" , data->max_uA); |
191 | } |
192 | |
193 | static 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(s: buf, base: 10, res: &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(lock: &data->lock); |
208 | |
209 | return count; |
210 | } |
211 | |
212 | static 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, fmt: "fast\n" ); |
220 | case REGULATOR_MODE_NORMAL: |
221 | return sprintf(buf, fmt: "normal\n" ); |
222 | case REGULATOR_MODE_IDLE: |
223 | return sprintf(buf, fmt: "idle\n" ); |
224 | case REGULATOR_MODE_STANDBY: |
225 | return sprintf(buf, fmt: "standby\n" ); |
226 | default: |
227 | return sprintf(buf, fmt: "unknown\n" ); |
228 | } |
229 | } |
230 | |
231 | static 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(s1: buf, s2: "fast\n" )) |
243 | mode = REGULATOR_MODE_FAST; |
244 | else if (sysfs_streq(s1: buf, s2: "normal\n" )) |
245 | mode = REGULATOR_MODE_NORMAL; |
246 | else if (sysfs_streq(s1: buf, s2: "idle\n" )) |
247 | mode = REGULATOR_MODE_IDLE; |
248 | else if (sysfs_streq(s1: buf, s2: "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(regulator: 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(lock: &data->lock); |
262 | |
263 | return count; |
264 | } |
265 | |
266 | static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV); |
267 | static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV); |
268 | static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA); |
269 | static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA); |
270 | static DEVICE_ATTR(mode, 0664, show_mode, set_mode); |
271 | |
272 | static 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 | |
281 | static const struct attribute_group regulator_virtual_attr_group = { |
282 | .attrs = regulator_virtual_attributes, |
283 | }; |
284 | |
285 | #ifdef CONFIG_OF |
286 | static const struct of_device_id regulator_virtual_consumer_of_match[] = { |
287 | { .compatible = "regulator-virtual-consumer" }, |
288 | {}, |
289 | }; |
290 | MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match); |
291 | #endif |
292 | |
293 | static int regulator_virtual_probe(struct platform_device *pdev) |
294 | { |
295 | char *reg_id = dev_get_platdata(dev: &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(dev: &pdev->dev, size: 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(dev: &pdev->dev, id: reg_id); |
328 | if (IS_ERR(ptr: drvdata->regulator)) |
329 | return dev_err_probe(dev: &pdev->dev, err: PTR_ERR(ptr: drvdata->regulator), |
330 | fmt: "Failed to obtain supply '%s'\n" , |
331 | reg_id); |
332 | |
333 | ret = sysfs_create_group(kobj: &pdev->dev.kobj, |
334 | grp: ®ulator_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(regulator: drvdata->regulator); |
342 | |
343 | platform_set_drvdata(pdev, data: drvdata); |
344 | |
345 | return 0; |
346 | } |
347 | |
348 | static void regulator_virtual_remove(struct platform_device *pdev) |
349 | { |
350 | struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); |
351 | |
352 | sysfs_remove_group(kobj: &pdev->dev.kobj, grp: ®ulator_virtual_attr_group); |
353 | |
354 | if (drvdata->enabled) |
355 | regulator_disable(regulator: drvdata->regulator); |
356 | } |
357 | |
358 | static struct platform_driver regulator_virtual_consumer_driver = { |
359 | .probe = regulator_virtual_probe, |
360 | .remove_new = 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 | |
368 | module_platform_driver(regulator_virtual_consumer_driver); |
369 | |
370 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>" ); |
371 | MODULE_DESCRIPTION("Virtual regulator consumer" ); |
372 | MODULE_LICENSE("GPL" ); |
373 | MODULE_ALIAS("platform:reg-virt-consumer" ); |
374 | |