tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/platform_device.h>
22#include <linux/regulator/consumer.h>
23#include <linux/regulator/userspace-consumer.h>
24
25struct userspace_consumer_data {
26 const char *name;
27
28 struct mutex lock;
29 bool enabled;
30
31 int num_supplies;
32 struct regulator_bulk_data *supplies;
33};
34
35static ssize_t reg_show_name(struct device *dev,
36 struct device_attribute *attr, char *buf)
37{
38 struct userspace_consumer_data *data = dev_get_drvdata(dev);
39
40 return sprintf(buf, "%s\n", data->name);
41}
42
43static ssize_t reg_show_state(struct device *dev,
44 struct device_attribute *attr, char *buf)
45{
46 struct userspace_consumer_data *data = dev_get_drvdata(dev);
47
48 if (data->enabled)
49 return sprintf(buf, "enabled\n");
50
51 return sprintf(buf, "disabled\n");
52}
53
54static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr,
55 const char *buf, size_t count)
56{
57 struct userspace_consumer_data *data = dev_get_drvdata(dev);
58 bool enabled;
59 int ret;
60
61 /*
62 * sysfs_streq() doesn't need the \n's, but we add them so the strings
63 * will be shared with show_state(), above.
64 */
65 if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
66 enabled = true;
67 else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
68 enabled = false;
69 else {
70 dev_err(dev, "Configuring invalid mode\n");
71 return count;
72 }
73
74 mutex_lock(&data->lock);
75 if (enabled != data->enabled) {
76 if (enabled)
77 ret = regulator_bulk_enable(data->num_supplies,
78 data->supplies);
79 else
80 ret = regulator_bulk_disable(data->num_supplies,
81 data->supplies);
82
83 if (ret == 0)
84 data->enabled = enabled;
85 else
86 dev_err(dev, "Failed to configure state: %d\n", ret);
87 }
88 mutex_unlock(&data->lock);
89
90 return count;
91}
92
93static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
94static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
95
96static struct attribute *attributes[] = {
97 &dev_attr_name.attr,
98 &dev_attr_state.attr,
99 NULL,
100};
101
102static const struct attribute_group attr_group = {
103 .attrs = attributes,
104};
105
106static int regulator_userspace_consumer_probe(struct platform_device *pdev)
107{
108 struct regulator_userspace_consumer_data *pdata;
109 struct userspace_consumer_data *drvdata;
110 int ret;
111
112 pdata = pdev->dev.platform_data;
113 if (!pdata)
114 return -EINVAL;
115
116 drvdata = kzalloc(sizeof(struct userspace_consumer_data), GFP_KERNEL);
117 if (drvdata == NULL)
118 return -ENOMEM;
119
120 drvdata->name = pdata->name;
121 drvdata->num_supplies = pdata->num_supplies;
122 drvdata->supplies = pdata->supplies;
123
124 mutex_init(&drvdata->lock);
125
126 ret = regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
127 drvdata->supplies);
128 if (ret) {
129 dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
130 goto err_alloc_supplies;
131 }
132
133 ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
134 if (ret != 0)
135 goto err_create_attrs;
136
137 if (pdata->init_on) {
138 ret = regulator_bulk_enable(drvdata->num_supplies,
139 drvdata->supplies);
140 if (ret) {
141 dev_err(&pdev->dev,
142 "Failed to set initial state: %d\n", ret);
143 goto err_enable;
144 }
145 }
146
147 drvdata->enabled = pdata->init_on;
148 platform_set_drvdata(pdev, drvdata);
149
150 return 0;
151
152err_enable:
153 sysfs_remove_group(&pdev->dev.kobj, &attr_group);
154
155err_create_attrs:
156 regulator_bulk_free(drvdata->num_supplies, drvdata->supplies);
157
158err_alloc_supplies:
159 kfree(drvdata);
160 return ret;
161}
162
163static int regulator_userspace_consumer_remove(struct platform_device *pdev)
164{
165 struct userspace_consumer_data *data = platform_get_drvdata(pdev);
166
167 sysfs_remove_group(&pdev->dev.kobj, &attr_group);
168
169 if (data->enabled)
170 regulator_bulk_disable(data->num_supplies, data->supplies);
171
172 regulator_bulk_free(data->num_supplies, data->supplies);
173 kfree(data);
174
175 return 0;
176}
177
178static struct platform_driver regulator_userspace_consumer_driver = {
179 .probe = regulator_userspace_consumer_probe,
180 .remove = regulator_userspace_consumer_remove,
181 .driver = {
182 .name = "reg-userspace-consumer",
183 },
184};
185
186
187static int __init regulator_userspace_consumer_init(void)
188{
189 return platform_driver_register(®ulator_userspace_consumer_driver);
190}
191module_init(regulator_userspace_consumer_init);
192
193static void __exit regulator_userspace_consumer_exit(void)
194{
195 platform_driver_unregister(®ulator_userspace_consumer_driver);
196}
197module_exit(regulator_userspace_consumer_exit);
198
199MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
200MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
201MODULE_LICENSE("GPL");