summaryrefslogtreecommitdiffstats
path: root/drivers/regulator/userspace-consumer.c
blob: 86a626a4f610a1563df10bbdf90a88aaef74f5b0 (plain)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * userspace-consumer.c
 *
 * Copyright 2009 CompuLab, Ltd.
 *
 * Author: Mike Rapoport <mike@compulab.co.il>
 *
 * Based of virtual consumer driver:
 *   Copyright 2008 Wolfson Microelectronics PLC.
 *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 */

#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/userspace-consumer.h>
#include <linux/slab.h>

struct userspace_consumer_data {
	const char *name;

	struct mutex lock;
	bool enabled;
	bool no_autoswitch;

	int num_supplies;
	struct regulator_bulk_data *supplies;
};

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

	return sprintf(buf, "%s\n", data->name);
}

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

	if (data->enabled)
		return sprintf(buf, "enabled\n");

	return sprintf(buf, "disabled\n");
}

static ssize_t state_store(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t count)
{
	struct userspace_consumer_data *data = dev_get_drvdata(dev);
	bool enabled;
	int ret;

	/*
	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
	 * will be shared with show_state(), above.
	 */
	if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
		enabled = true;
	else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
		enabled = false;
	else {
		dev_err(dev, "Configuring invalid mode\n");
		return count;
	}

	mutex_lock(&data->lock);
	if (enabled != data->enabled) {
		if (enabled)
			ret = regulator_bulk_enable(data->num_supplies,
						    data->supplies);
		else
			ret = regulator_bulk_disable(data->num_supplies,
						     data->supplies);

		if (ret == 0)
			data->enabled = enabled;
		else
			dev_err(dev, "Failed to configure state: %d\n", ret);
	}
	mutex_unlock(&data->lock);

	return count;
}

static DEVICE_ATTR_RO(name);
static DEVICE_ATTR_RW(state);

static struct attribute *attributes[] = {
	&dev_attr_name.attr,
	&dev_attr_state.attr,
	NULL,
};

static umode_t attr_visible(struct kobject *kobj, struct attribute *attr, int idx)
{
	struct device *dev = kobj_to_dev(kobj);
	struct userspace_consumer_data *data = dev_get_drvdata(dev);

	/* If a name hasn't been set, don't bother with the attribute */
	if (attr == &dev_attr_name.attr && !data->name)
		return 0;

	return attr->mode;
}

static const struct attribute_group attr_group = {
	.attrs	= attributes,
	.is_visible =  attr_visible,
};

static int regulator_userspace_consumer_probe(struct platform_device *pdev)
{
	struct regulator_userspace_consumer_data tmpdata;
	struct regulator_userspace_consumer_data *pdata;
	struct userspace_consumer_data *drvdata;
	int ret;

	pdata = dev_get_platdata(&pdev->dev);
	if (!pdata) {
		if (!pdev->dev.of_node)
			return -EINVAL;

		pdata = &tmpdata;
		memset(pdata, 0, sizeof(*pdata));

		pdata->no_autoswitch = true;
		pdata->num_supplies = 1;
		pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);
		if (!pdata->supplies)
			return -ENOMEM;
		pdata->supplies[0].supply = "vout";
	}

	if (pdata->num_supplies < 1) {
		dev_err(&pdev->dev, "At least one supply required\n");
		return -EINVAL;
	}

	drvdata = devm_kzalloc(&pdev->dev,
			       sizeof(struct userspace_consumer_data),
			       GFP_KERNEL);
	if (drvdata == NULL)
		return -ENOMEM;

	drvdata->name = pdata->name;
	drvdata->num_supplies = pdata->num_supplies;
	drvdata->supplies = pdata->supplies;
	drvdata->no_autoswitch = pdata->no_autoswitch;

	mutex_init(&drvdata->lock);

	ret = devm_regulator_bulk_get_exclusive(&pdev->dev, drvdata->num_supplies,
						drvdata->supplies);
	if (ret) {
		dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, drvdata);

	ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
	if (ret != 0)
		return ret;

	if (pdata->init_on && !pdata->no_autoswitch) {
		ret = regulator_bulk_enable(drvdata->num_supplies,
					    drvdata->supplies);
		if (ret) {
			dev_err(&pdev->dev,
				"Failed to set initial state: %d\n", ret);
			goto err_enable;
		}
	}

	ret = regulator_is_enabled(pdata->supplies[0].consumer);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to get regulator status\n");
		goto err_enable;
	}
	drvdata->enabled = !!ret;

	return 0;

err_enable:
	sysfs_remove_group(&pdev->dev.kobj, &attr_group);

	return ret;
}

static void regulator_userspace_consumer_remove(struct platform_device *pdev)
{
	struct userspace_consumer_data *data = platform_get_drvdata(pdev);

	sysfs_remove_group(&pdev->dev.kobj, &attr_group);

	if (data->enabled && !data->no_autoswitch)
		regulator_bulk_disable(data->num_supplies, data->supplies);
}

static const struct of_device_id regulator_userspace_consumer_of_match[] = {
	{ .compatible = "regulator-output", },
	{},
};
MODULE_DEVICE_TABLE(of, regulator_userspace_consumer_of_match);

static struct platform_driver regulator_userspace_consumer_driver = {
	.probe		= regulator_userspace_consumer_probe,
	.remove_new	= regulator_userspace_consumer_remove,
	.driver		= {
		.name		= "reg-userspace-consumer",
		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
		.of_match_table	= regulator_userspace_consumer_of_match,
	},
};

module_platform_driver(regulator_userspace_consumer_driver);

MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
MODULE_LICENSE("GPL");