Merge branch 'for-2.6.27' of git://linux-nfs.org/~bfields/linux
[linux-2.6] / drivers / regulator / fixed.c
1 /*
2  * fixed.c
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  * This is useful for systems with mixed controllable and
14  * non-controllable regulators, as well as for allowing testing on
15  * systems with no controllable regulators.
16  */
17
18 #include <linux/err.h>
19 #include <linux/mutex.h>
20 #include <linux/platform_device.h>
21 #include <linux/regulator/driver.h>
22 #include <linux/regulator/fixed.h>
23
24 struct fixed_voltage_data {
25         struct regulator_desc desc;
26         struct regulator_dev *dev;
27         int microvolts;
28 };
29
30 static int fixed_voltage_is_enabled(struct regulator_dev *dev)
31 {
32         return 1;
33 }
34
35 static int fixed_voltage_enable(struct regulator_dev *dev)
36 {
37         return 0;
38 }
39
40 static int fixed_voltage_get_voltage(struct regulator_dev *dev)
41 {
42         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
43
44         return data->microvolts;
45 }
46
47 static struct regulator_ops fixed_voltage_ops = {
48         .is_enabled = fixed_voltage_is_enabled,
49         .enable = fixed_voltage_enable,
50         .get_voltage = fixed_voltage_get_voltage,
51 };
52
53 static int regulator_fixed_voltage_probe(struct platform_device *pdev)
54 {
55         struct fixed_voltage_config *config = pdev->dev.platform_data;
56         struct fixed_voltage_data *drvdata;
57         int ret;
58
59         drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
60         if (drvdata == NULL) {
61                 ret = -ENOMEM;
62                 goto err;
63         }
64
65         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
66         if (drvdata->desc.name == NULL) {
67                 ret = -ENOMEM;
68                 goto err;
69         }
70         drvdata->desc.type = REGULATOR_VOLTAGE;
71         drvdata->desc.owner = THIS_MODULE;
72         drvdata->desc.ops = &fixed_voltage_ops,
73
74         drvdata->microvolts = config->microvolts;
75
76         drvdata->dev = regulator_register(&drvdata->desc, drvdata);
77         if (IS_ERR(drvdata->dev)) {
78                 ret = PTR_ERR(drvdata->dev);
79                 goto err_name;
80         }
81
82         platform_set_drvdata(pdev, drvdata);
83
84         dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
85                 drvdata->microvolts);
86
87         return 0;
88
89 err_name:
90         kfree(drvdata->desc.name);
91 err:
92         kfree(drvdata);
93         return ret;
94 }
95
96 static int regulator_fixed_voltage_remove(struct platform_device *pdev)
97 {
98         struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
99
100         regulator_unregister(drvdata->dev);
101         kfree(drvdata->desc.name);
102         kfree(drvdata);
103
104         return 0;
105 }
106
107 static struct platform_driver regulator_fixed_voltage_driver = {
108         .probe          = regulator_fixed_voltage_probe,
109         .remove         = regulator_fixed_voltage_remove,
110         .driver         = {
111                 .name           = "reg-fixed-voltage",
112         },
113 };
114
115 static int __init regulator_fixed_voltage_init(void)
116 {
117         return platform_driver_register(&regulator_fixed_voltage_driver);
118 }
119 module_init(regulator_fixed_voltage_init);
120
121 static void __exit regulator_fixed_voltage_exit(void)
122 {
123         platform_driver_unregister(&regulator_fixed_voltage_driver);
124 }
125 module_exit(regulator_fixed_voltage_exit);
126
127 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
128 MODULE_DESCRIPTION("Fixed voltage regulator");
129 MODULE_LICENSE("GPL");