xref: /openbmc/linux/drivers/regulator/virtual.c (revision 275876e2)
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 #include <linux/module.h>
20 
21 struct virtual_consumer_data {
22 	struct mutex lock;
23 	struct regulator *regulator;
24 	bool enabled;
25 	int min_uV;
26 	int max_uV;
27 	int min_uA;
28 	int max_uA;
29 	unsigned int mode;
30 };
31 
32 static void update_voltage_constraints(struct device *dev,
33 				       struct virtual_consumer_data *data)
34 {
35 	int ret;
36 
37 	if (data->min_uV && data->max_uV
38 	    && data->min_uV <= data->max_uV) {
39 		dev_dbg(dev, "Requesting %d-%duV\n",
40 			data->min_uV, data->max_uV);
41 		ret = regulator_set_voltage(data->regulator,
42 					data->min_uV, data->max_uV);
43 		if (ret != 0) {
44 			dev_err(dev,
45 				"regulator_set_voltage() failed: %d\n", ret);
46 			return;
47 		}
48 	}
49 
50 	if (data->min_uV && data->max_uV && !data->enabled) {
51 		dev_dbg(dev, "Enabling regulator\n");
52 		ret = regulator_enable(data->regulator);
53 		if (ret == 0)
54 			data->enabled = true;
55 		else
56 			dev_err(dev, "regulator_enable() failed: %d\n",
57 				ret);
58 	}
59 
60 	if (!(data->min_uV && data->max_uV) && data->enabled) {
61 		dev_dbg(dev, "Disabling regulator\n");
62 		ret = regulator_disable(data->regulator);
63 		if (ret == 0)
64 			data->enabled = false;
65 		else
66 			dev_err(dev, "regulator_disable() failed: %d\n",
67 				ret);
68 	}
69 }
70 
71 static void update_current_limit_constraints(struct device *dev,
72 					  struct virtual_consumer_data *data)
73 {
74 	int ret;
75 
76 	if (data->max_uA
77 	    && data->min_uA <= data->max_uA) {
78 		dev_dbg(dev, "Requesting %d-%duA\n",
79 			data->min_uA, data->max_uA);
80 		ret = regulator_set_current_limit(data->regulator,
81 					data->min_uA, data->max_uA);
82 		if (ret != 0) {
83 			dev_err(dev,
84 				"regulator_set_current_limit() failed: %d\n",
85 				ret);
86 			return;
87 		}
88 	}
89 
90 	if (data->max_uA && !data->enabled) {
91 		dev_dbg(dev, "Enabling regulator\n");
92 		ret = regulator_enable(data->regulator);
93 		if (ret == 0)
94 			data->enabled = true;
95 		else
96 			dev_err(dev, "regulator_enable() failed: %d\n",
97 				ret);
98 	}
99 
100 	if (!(data->min_uA && data->max_uA) && data->enabled) {
101 		dev_dbg(dev, "Disabling regulator\n");
102 		ret = regulator_disable(data->regulator);
103 		if (ret == 0)
104 			data->enabled = false;
105 		else
106 			dev_err(dev, "regulator_disable() failed: %d\n",
107 				ret);
108 	}
109 }
110 
111 static ssize_t show_min_uV(struct device *dev,
112 			   struct device_attribute *attr, char *buf)
113 {
114 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
115 	return sprintf(buf, "%d\n", data->min_uV);
116 }
117 
118 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
119 			  const char *buf, size_t count)
120 {
121 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
122 	long val;
123 
124 	if (kstrtol(buf, 10, &val) != 0)
125 		return count;
126 
127 	mutex_lock(&data->lock);
128 
129 	data->min_uV = val;
130 	update_voltage_constraints(dev, data);
131 
132 	mutex_unlock(&data->lock);
133 
134 	return count;
135 }
136 
137 static ssize_t show_max_uV(struct device *dev,
138 			   struct device_attribute *attr, char *buf)
139 {
140 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
141 	return sprintf(buf, "%d\n", data->max_uV);
142 }
143 
144 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
145 			  const char *buf, size_t count)
146 {
147 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
148 	long val;
149 
150 	if (kstrtol(buf, 10, &val) != 0)
151 		return count;
152 
153 	mutex_lock(&data->lock);
154 
155 	data->max_uV = val;
156 	update_voltage_constraints(dev, data);
157 
158 	mutex_unlock(&data->lock);
159 
160 	return count;
161 }
162 
163 static ssize_t show_min_uA(struct device *dev,
164 			   struct device_attribute *attr, char *buf)
165 {
166 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
167 	return sprintf(buf, "%d\n", data->min_uA);
168 }
169 
170 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
171 			  const char *buf, size_t count)
172 {
173 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
174 	long val;
175 
176 	if (kstrtol(buf, 10, &val) != 0)
177 		return count;
178 
179 	mutex_lock(&data->lock);
180 
181 	data->min_uA = val;
182 	update_current_limit_constraints(dev, data);
183 
184 	mutex_unlock(&data->lock);
185 
186 	return count;
187 }
188 
189 static ssize_t show_max_uA(struct device *dev,
190 			   struct device_attribute *attr, char *buf)
191 {
192 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
193 	return sprintf(buf, "%d\n", data->max_uA);
194 }
195 
196 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
197 			  const char *buf, size_t count)
198 {
199 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
200 	long val;
201 
202 	if (kstrtol(buf, 10, &val) != 0)
203 		return count;
204 
205 	mutex_lock(&data->lock);
206 
207 	data->max_uA = val;
208 	update_current_limit_constraints(dev, data);
209 
210 	mutex_unlock(&data->lock);
211 
212 	return count;
213 }
214 
215 static ssize_t show_mode(struct device *dev,
216 			 struct device_attribute *attr, char *buf)
217 {
218 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
219 
220 	switch (data->mode) {
221 	case REGULATOR_MODE_FAST:
222 		return sprintf(buf, "fast\n");
223 	case REGULATOR_MODE_NORMAL:
224 		return sprintf(buf, "normal\n");
225 	case REGULATOR_MODE_IDLE:
226 		return sprintf(buf, "idle\n");
227 	case REGULATOR_MODE_STANDBY:
228 		return sprintf(buf, "standby\n");
229 	default:
230 		return sprintf(buf, "unknown\n");
231 	}
232 }
233 
234 static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
235 			const char *buf, size_t count)
236 {
237 	struct virtual_consumer_data *data = dev_get_drvdata(dev);
238 	unsigned int mode;
239 	int ret;
240 
241 	/*
242 	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
243 	 * will be shared with show_mode(), above.
244 	 */
245 	if (sysfs_streq(buf, "fast\n"))
246 		mode = REGULATOR_MODE_FAST;
247 	else if (sysfs_streq(buf, "normal\n"))
248 		mode = REGULATOR_MODE_NORMAL;
249 	else if (sysfs_streq(buf, "idle\n"))
250 		mode = REGULATOR_MODE_IDLE;
251 	else if (sysfs_streq(buf, "standby\n"))
252 		mode = REGULATOR_MODE_STANDBY;
253 	else {
254 		dev_err(dev, "Configuring invalid mode\n");
255 		return count;
256 	}
257 
258 	mutex_lock(&data->lock);
259 	ret = regulator_set_mode(data->regulator, mode);
260 	if (ret == 0)
261 		data->mode = mode;
262 	else
263 		dev_err(dev, "Failed to configure mode: %d\n", ret);
264 	mutex_unlock(&data->lock);
265 
266 	return count;
267 }
268 
269 static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
270 static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
271 static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
272 static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
273 static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
274 
275 static struct attribute *regulator_virtual_attributes[] = {
276 	&dev_attr_min_microvolts.attr,
277 	&dev_attr_max_microvolts.attr,
278 	&dev_attr_min_microamps.attr,
279 	&dev_attr_max_microamps.attr,
280 	&dev_attr_mode.attr,
281 	NULL
282 };
283 
284 static const struct attribute_group regulator_virtual_attr_group = {
285 	.attrs	= regulator_virtual_attributes,
286 };
287 
288 static int regulator_virtual_probe(struct platform_device *pdev)
289 {
290 	char *reg_id = dev_get_platdata(&pdev->dev);
291 	struct virtual_consumer_data *drvdata;
292 	int ret;
293 
294 	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
295 			       GFP_KERNEL);
296 	if (drvdata == NULL)
297 		return -ENOMEM;
298 
299 	mutex_init(&drvdata->lock);
300 
301 	drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
302 	if (IS_ERR(drvdata->regulator)) {
303 		ret = PTR_ERR(drvdata->regulator);
304 		dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
305 			reg_id, ret);
306 		return ret;
307 	}
308 
309 	ret = sysfs_create_group(&pdev->dev.kobj,
310 				 &regulator_virtual_attr_group);
311 	if (ret != 0) {
312 		dev_err(&pdev->dev,
313 			"Failed to create attribute group: %d\n", ret);
314 		return ret;
315 	}
316 
317 	drvdata->mode = regulator_get_mode(drvdata->regulator);
318 
319 	platform_set_drvdata(pdev, drvdata);
320 
321 	return 0;
322 }
323 
324 static int regulator_virtual_remove(struct platform_device *pdev)
325 {
326 	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
327 
328 	sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
329 
330 	if (drvdata->enabled)
331 		regulator_disable(drvdata->regulator);
332 
333 	return 0;
334 }
335 
336 static struct platform_driver regulator_virtual_consumer_driver = {
337 	.probe		= regulator_virtual_probe,
338 	.remove		= regulator_virtual_remove,
339 	.driver		= {
340 		.name		= "reg-virt-consumer",
341 		.owner		= THIS_MODULE,
342 	},
343 };
344 
345 module_platform_driver(regulator_virtual_consumer_driver);
346 
347 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
348 MODULE_DESCRIPTION("Virtual regulator consumer");
349 MODULE_LICENSE("GPL");
350 MODULE_ALIAS("platform:reg-virt-consumer");
351