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(®ulator_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(®ulator_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"); 130