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");