regulator: palmas: fix build warnings
[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/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
27 struct 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
37 static 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
45 static 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
56 static 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
95 static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
96 static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
97
98 static struct attribute *attributes[] = {
99         &dev_attr_name.attr,
100         &dev_attr_state.attr,
101         NULL,
102 };
103
104 static const struct attribute_group attr_group = {
105         .attrs  = attributes,
106 };
107
108 static 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 = pdev->dev.platform_data;
115         if (!pdata)
116                 return -EINVAL;
117
118         drvdata = kzalloc(sizeof(struct userspace_consumer_data), GFP_KERNEL);
119         if (drvdata == NULL)
120                 return -ENOMEM;
121
122         drvdata->name = pdata->name;
123         drvdata->num_supplies = pdata->num_supplies;
124         drvdata->supplies = pdata->supplies;
125
126         mutex_init(&drvdata->lock);
127
128         ret = regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
129                                  drvdata->supplies);
130         if (ret) {
131                 dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
132                 goto err_alloc_supplies;
133         }
134
135         ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
136         if (ret != 0)
137                 goto err_create_attrs;
138
139         if (pdata->init_on) {
140                 ret = regulator_bulk_enable(drvdata->num_supplies,
141                                             drvdata->supplies);
142                 if (ret) {
143                         dev_err(&pdev->dev,
144                                 "Failed to set initial state: %d\n", ret);
145                         goto err_enable;
146                 }
147         }
148
149         drvdata->enabled = pdata->init_on;
150         platform_set_drvdata(pdev, drvdata);
151
152         return 0;
153
154 err_enable:
155         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
156
157 err_create_attrs:
158         regulator_bulk_free(drvdata->num_supplies, drvdata->supplies);
159
160 err_alloc_supplies:
161         kfree(drvdata);
162         return ret;
163 }
164
165 static int regulator_userspace_consumer_remove(struct platform_device *pdev)
166 {
167         struct userspace_consumer_data *data = platform_get_drvdata(pdev);
168
169         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
170
171         if (data->enabled)
172                 regulator_bulk_disable(data->num_supplies, data->supplies);
173
174         regulator_bulk_free(data->num_supplies, data->supplies);
175         kfree(data);
176
177         return 0;
178 }
179
180 static struct platform_driver regulator_userspace_consumer_driver = {
181         .probe          = regulator_userspace_consumer_probe,
182         .remove         = regulator_userspace_consumer_remove,
183         .driver         = {
184                 .name           = "reg-userspace-consumer",
185         },
186 };
187
188 module_platform_driver(regulator_userspace_consumer_driver);
189
190 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
191 MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
192 MODULE_LICENSE("GPL");