Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / drivers / regulator / userspace-consumer.c
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
25 struct 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
35 static 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
43 static 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
54 static 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
93 static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
94 static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
95
96 static struct attribute *attributes[] = {
97         &dev_attr_name.attr,
98         &dev_attr_state.attr,
99         NULL,
100 };
101
102 static const struct attribute_group attr_group = {
103         .attrs  = attributes,
104 };
105
106 static 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
152 err_enable:
153         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
154
155 err_create_attrs:
156         regulator_bulk_free(drvdata->num_supplies, drvdata->supplies);
157
158 err_alloc_supplies:
159         kfree(drvdata);
160         return ret;
161 }
162
163 static 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
178 static 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
187 static int __init regulator_userspace_consumer_init(void)
188 {
189         return platform_driver_register(&regulator_userspace_consumer_driver);
190 }
191 module_init(regulator_userspace_consumer_init);
192
193 static void __exit regulator_userspace_consumer_exit(void)
194 {
195         platform_driver_unregister(&regulator_userspace_consumer_driver);
196 }
197 module_exit(regulator_userspace_consumer_exit);
198
199 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
200 MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
201 MODULE_LICENSE("GPL");