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 int fixed_voltage_list_voltage(struct regulator_dev *dev, 48 unsigned selector) 49 { 50 struct fixed_voltage_data *data = rdev_get_drvdata(dev); 51 52 if (selector != 0) 53 return -EINVAL; 54 55 return data->microvolts; 56 } 57 58 static struct regulator_ops fixed_voltage_ops = { 59 .is_enabled = fixed_voltage_is_enabled, 60 .enable = fixed_voltage_enable, 61 .get_voltage = fixed_voltage_get_voltage, 62 .list_voltage = fixed_voltage_list_voltage, 63 }; 64 65 static int regulator_fixed_voltage_probe(struct platform_device *pdev) 66 { 67 struct fixed_voltage_config *config = pdev->dev.platform_data; 68 struct fixed_voltage_data *drvdata; 69 int ret; 70 71 drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL); 72 if (drvdata == NULL) { 73 ret = -ENOMEM; 74 goto err; 75 } 76 77 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); 78 if (drvdata->desc.name == NULL) { 79 ret = -ENOMEM; 80 goto err; 81 } 82 drvdata->desc.type = REGULATOR_VOLTAGE; 83 drvdata->desc.owner = THIS_MODULE; 84 drvdata->desc.ops = &fixed_voltage_ops; 85 drvdata->desc.n_voltages = 1; 86 87 drvdata->microvolts = config->microvolts; 88 89 drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev, 90 config->init_data, drvdata); 91 if (IS_ERR(drvdata->dev)) { 92 ret = PTR_ERR(drvdata->dev); 93 goto err_name; 94 } 95 96 platform_set_drvdata(pdev, drvdata); 97 98 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, 99 drvdata->microvolts); 100 101 return 0; 102 103 err_name: 104 kfree(drvdata->desc.name); 105 err: 106 kfree(drvdata); 107 return ret; 108 } 109 110 static int regulator_fixed_voltage_remove(struct platform_device *pdev) 111 { 112 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev); 113 114 regulator_unregister(drvdata->dev); 115 kfree(drvdata->desc.name); 116 kfree(drvdata); 117 118 return 0; 119 } 120 121 static struct platform_driver regulator_fixed_voltage_driver = { 122 .probe = regulator_fixed_voltage_probe, 123 .remove = regulator_fixed_voltage_remove, 124 .driver = { 125 .name = "reg-fixed-voltage", 126 }, 127 }; 128 129 static int __init regulator_fixed_voltage_init(void) 130 { 131 return platform_driver_register(®ulator_fixed_voltage_driver); 132 } 133 subsys_initcall(regulator_fixed_voltage_init); 134 135 static void __exit regulator_fixed_voltage_exit(void) 136 { 137 platform_driver_unregister(®ulator_fixed_voltage_driver); 138 } 139 module_exit(regulator_fixed_voltage_exit); 140 141 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 142 MODULE_DESCRIPTION("Fixed voltage regulator"); 143 MODULE_LICENSE("GPL"); 144 MODULE_ALIAS("platform:reg-fixed-voltage"); 145