aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/regulator/virtual.c
blob: 144110788fd272ca1d52fe96e0b75f29f2fb1959 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
/*
 * reg-virtual-consumer.c
 *
 * Copyright 2008 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 */

#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

struct virtual_consumer_data {
	struct mutex lock;
	struct regulator *regulator;
	int enabled;
	int min_uV;
	int max_uV;
	int min_uA;
	int max_uA;
	unsigned int mode;
};

static void update_voltage_constraints(struct device *dev,
				       struct virtual_consumer_data *data)
{
	int ret;

	if (data->min_uV && data->max_uV
	    && data->min_uV <= data->max_uV) {
		dev_dbg(dev, "Requesting %d-%duV\n",
			data->min_uV, data->max_uV);
		ret = regulator_set_voltage(data->regulator,
					data->min_uV, data->max_uV);
		if (ret != 0) {
			dev_err(dev,
				"regulator_set_voltage() failed: %d\n", ret);
			return;
		}
	}

	if (data->min_uV && data->max_uV && !data->enabled) {
		dev_dbg(dev, "Enabling regulator\n");
		ret = regulator_enable(data->regulator);
		if (ret == 0)
			data->enabled = 1;
		else
			dev_err(dev, "regulator_enable() failed: %d\n",
				ret);
	}

	if (!(data->min_uV && data->max_uV) && data->enabled) {
		dev_dbg(dev, "Disabling regulator\n");
		ret = regulator_disable(data->regulator);
		if (ret == 0)
			data->enabled = 0;
		else
			dev_err(dev, "regulator_disable() failed: %d\n",
				ret);
	}
}

static void update_current_limit_constraints(struct device *dev,
					  struct virtual_consumer_data *data)
{
	int ret;

	if (data->max_uA
	    && data->min_uA <= data->max_uA) {
		dev_dbg(dev, "Requesting %d-%duA\n",
			data->min_uA, data->max_uA);
		ret = regulator_set_current_limit(data->regulator,
					data->min_uA, data->max_uA);
		if (ret != 0) {
			dev_err(dev,
				"regulator_set_current_limit() failed: %d\n",
				ret);
			return;
		}
	}

	if (data->max_uA && !data->enabled) {
		dev_dbg(dev, "Enabling regulator\n");
		ret = regulator_enable(data->regulator);
		if (ret == 0)
			data->enabled = 1;
		else
			dev_err(dev, "regulator_enable() failed: %d\n",
				ret);
	}

	if (!(data->min_uA && data->max_uA) && data->enabled) {
		dev_dbg(dev, "Disabling regulator\n");
		ret = regulator_disable(data->regulator);
		if (ret == 0)
			data->enabled = 0;
		else
			dev_err(dev, "regulator_disable() failed: %d\n",
				ret);
	}
}

static ssize_t show_min_uV(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->min_uV);
}

static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (strict_strtol(buf, 10, &val) != 0)
		return count;

	mutex_lock(&data->lock);

	data->min_uV = val;
	update_voltage_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
}

static ssize_t show_max_uV(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->max_uV);
}

static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (strict_strtol(buf, 10, &val) != 0)
		return count;

	mutex_lock(&data->lock);

	data->max_uV = val;
	update_voltage_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
}

static ssize_t show_min_uA(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->min_uA);
}

static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (strict_strtol(buf, 10, &val) != 0)
		return count;

	mutex_lock(&data->lock);

	data->min_uA = val;
	update_current_limit_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
}

static ssize_t show_max_uA(struct device *dev,
			   struct device_attribute *attr, char *buf)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->max_uA);
}

static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	long val;

	if (strict_strtol(buf, 10, &val) != 0)
		return count;

	mutex_lock(&data->lock);

	data->max_uA = val;
	update_current_limit_constraints(dev, data);

	mutex_unlock(&data->lock);

	return count;
}

static ssize_t show_mode(struct device *dev,
			 struct device_attribute *attr, char *buf)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);

	switch (data->mode) {
	case REGULATOR_MODE_FAST:
		return sprintf(buf, "fast\n");
	case REGULATOR_MODE_NORMAL:
		return sprintf(buf, "normal\n");
	case REGULATOR_MODE_IDLE:
		return sprintf(buf, "idle\n");
	case REGULATOR_MODE_STANDBY:
		return sprintf(buf, "standby\n");
	default:
		return sprintf(buf, "unknown\n");
	}
}

static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct virtual_consumer_data *data = dev_get_drvdata(dev);
	unsigned int mode;
	int ret;

	/*
	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
	 * will be shared with show_mode(), above.
	 */
	if (sysfs_streq(buf, "fast\n"))
		mode = REGULATOR_MODE_FAST;
	else if (sysfs_streq(buf, "normal\n"))
		mode = REGULATOR_MODE_NORMAL;
	else if (sysfs_streq(buf, "idle\n"))
		mode = REGULATOR_MODE_IDLE;
	else if (sysfs_streq(buf, "standby\n"))
		mode = REGULATOR_MODE_STANDBY;
	else {
		dev_err(dev, "Configuring invalid mode\n");
		return count;
	}

	mutex_lock(&data->lock);
	ret = regulator_set_mode(data->regulator, mode);
	if (ret == 0)
		data->mode = mode;
	else
		dev_err(dev, "Failed to configure mode: %d\n", ret);
	mutex_unlock(&data->lock);

	return count;
}

static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
static DEVICE_ATTR(mode, 0666, show_mode, set_mode);

static struct device_attribute *attributes[] = {
	&dev_attr_min_microvolts,
	&dev_attr_max_microvolts,
	&dev_attr_min_microamps,
	&dev_attr_max_microamps,
	&dev_attr_mode,
};

static int regulator_virtual_consumer_probe(struct platform_device *pdev)
{
	char *reg_id = pdev->dev.platform_data;
	struct virtual_consumer_data *drvdata;
	int ret, i;

	drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL);
	if (drvdata == NULL) {
		ret = -ENOMEM;
		goto err;
	}

	mutex_init(&drvdata->lock);

	drvdata->regulator = regulator_get(&pdev->dev, reg_id);
	if (IS_ERR(drvdata->regulator)) {
		ret = PTR_ERR(drvdata->regulator);
		dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
			reg_id, ret);
		goto err;
	}

	for (i = 0; i < ARRAY_SIZE(attributes); i++) {
		ret = device_create_file(&pdev->dev, attributes[i]);
		if (ret != 0)
			goto err;
	}

	drvdata->mode = regulator_get_mode(drvdata->regulator);

	platform_set_drvdata(pdev, drvdata);

	return 0;

err:
	for (i = 0; i < ARRAY_SIZE(attributes); i++)
		device_remove_file(&pdev->dev, attributes[i]);
	kfree(drvdata);
	return ret;
}

static int regulator_virtual_consumer_remove(struct platform_device *pdev)
{
	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(attributes); i++)
		device_remove_file(&pdev->dev, attributes[i]);
	if (drvdata->enabled)
		regulator_disable(drvdata->regulator);
	regulator_put(drvdata->regulator);

	kfree(drvdata);

	return 0;
}

static struct platform_driver regulator_virtual_consumer_driver = {
	.probe		= regulator_virtual_consumer_probe,
	.remove		= regulator_virtual_consumer_remove,
	.driver		= {
		.name		= "reg-virt-consumer",
	},
};


static int __init regulator_virtual_consumer_init(void)
{
	return platform_driver_register(&regulator_virtual_consumer_driver);
}
module_init(regulator_virtual_consumer_init);

static void __exit regulator_virtual_consumer_exit(void)
{
	platform_driver_unregister(&regulator_virtual_consumer_driver);
}
module_exit(regulator_virtual_consumer_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Virtual regulator consumer");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:reg-virt-consumer");