[go: nahoru, domu]
1/*
2 * userspace-consumer.c
3 *
4 * Copyright 2009 CompuLab, Ltd.
5 *
6 * Author: Mike Rapoport <mike@compulab.co.il>
7 *
8 * Based of virtual consumer driver:
9 *   Copyright 2008 Wolfson Microelectronics PLC.
10 *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 */
18
19#include <linux/err.h>
20#include <linux/mutex.h>
21#include <linux/module.h>
22#include <linux/platform_device.h>
23#include <linux/regulator/consumer.h>
24#include <linux/regulator/userspace-consumer.h>
25#include <linux/slab.h>
26
27struct userspace_consumer_data {
28	const char *name;
29
30	struct mutex lock;
31	bool enabled;
32
33	int num_supplies;
34	struct regulator_bulk_data *supplies;
35};
36
37static ssize_t reg_show_name(struct device *dev,
38			  struct device_attribute *attr, char *buf)
39{
40	struct userspace_consumer_data *data = dev_get_drvdata(dev);
41
42	return sprintf(buf, "%s\n", data->name);
43}
44
45static ssize_t reg_show_state(struct device *dev,
46			  struct device_attribute *attr, char *buf)
47{
48	struct userspace_consumer_data *data = dev_get_drvdata(dev);
49
50	if (data->enabled)
51		return sprintf(buf, "enabled\n");
52
53	return sprintf(buf, "disabled\n");
54}
55
56static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr,
57			 const char *buf, size_t count)
58{
59	struct userspace_consumer_data *data = dev_get_drvdata(dev);
60	bool enabled;
61	int ret;
62
63	/*
64	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
65	 * will be shared with show_state(), above.
66	 */
67	if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
68		enabled = true;
69	else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
70		enabled = false;
71	else {
72		dev_err(dev, "Configuring invalid mode\n");
73		return count;
74	}
75
76	mutex_lock(&data->lock);
77	if (enabled != data->enabled) {
78		if (enabled)
79			ret = regulator_bulk_enable(data->num_supplies,
80						    data->supplies);
81		else
82			ret = regulator_bulk_disable(data->num_supplies,
83						     data->supplies);
84
85		if (ret == 0)
86			data->enabled = enabled;
87		else
88			dev_err(dev, "Failed to configure state: %d\n", ret);
89	}
90	mutex_unlock(&data->lock);
91
92	return count;
93}
94
95static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
96static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
97
98static struct attribute *attributes[] = {
99	&dev_attr_name.attr,
100	&dev_attr_state.attr,
101	NULL,
102};
103
104static const struct attribute_group attr_group = {
105	.attrs	= attributes,
106};
107
108static int regulator_userspace_consumer_probe(struct platform_device *pdev)
109{
110	struct regulator_userspace_consumer_data *pdata;
111	struct userspace_consumer_data *drvdata;
112	int ret;
113
114	pdata = dev_get_platdata(&pdev->dev);
115	if (!pdata)
116		return -EINVAL;
117
118	drvdata = devm_kzalloc(&pdev->dev,
119			       sizeof(struct userspace_consumer_data),
120			       GFP_KERNEL);
121	if (drvdata == NULL)
122		return -ENOMEM;
123
124	drvdata->name = pdata->name;
125	drvdata->num_supplies = pdata->num_supplies;
126	drvdata->supplies = pdata->supplies;
127
128	mutex_init(&drvdata->lock);
129
130	ret = devm_regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
131				      drvdata->supplies);
132	if (ret) {
133		dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
134		return ret;
135	}
136
137	ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
138	if (ret != 0)
139		return ret;
140
141	if (pdata->init_on) {
142		ret = regulator_bulk_enable(drvdata->num_supplies,
143					    drvdata->supplies);
144		if (ret) {
145			dev_err(&pdev->dev,
146				"Failed to set initial state: %d\n", ret);
147			goto err_enable;
148		}
149	}
150
151	drvdata->enabled = pdata->init_on;
152	platform_set_drvdata(pdev, drvdata);
153
154	return 0;
155
156err_enable:
157	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
158
159	return ret;
160}
161
162static int regulator_userspace_consumer_remove(struct platform_device *pdev)
163{
164	struct userspace_consumer_data *data = platform_get_drvdata(pdev);
165
166	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
167
168	if (data->enabled)
169		regulator_bulk_disable(data->num_supplies, data->supplies);
170
171	return 0;
172}
173
174static struct platform_driver regulator_userspace_consumer_driver = {
175	.probe		= regulator_userspace_consumer_probe,
176	.remove		= regulator_userspace_consumer_remove,
177	.driver		= {
178		.name		= "reg-userspace-consumer",
179	},
180};
181
182module_platform_driver(regulator_userspace_consumer_driver);
183
184MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
185MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
186MODULE_LICENSE("GPL");
187