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/platform_device.h> 22#include <linux/regulator/consumer.h> 23#include <linux/regulator/userspace-consumer.h> 24#include <linux/slab.h> 25 26struct userspace_consumer_data { 27 const char *name; 28 29 struct mutex lock; 30 bool enabled; 31 32 int num_supplies; 33 struct regulator_bulk_data *supplies; 34}; 35 36static ssize_t reg_show_name(struct device *dev, 37 struct device_attribute *attr, char *buf) 38{ 39 struct userspace_consumer_data *data = dev_get_drvdata(dev); 40 41 return sprintf(buf, "%s\n", data->name); 42} 43 44static ssize_t reg_show_state(struct device *dev, 45 struct device_attribute *attr, char *buf) 46{ 47 struct userspace_consumer_data *data = dev_get_drvdata(dev); 48 49 if (data->enabled) 50 return sprintf(buf, "enabled\n"); 51 52 return sprintf(buf, "disabled\n"); 53} 54 55static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr, 56 const char *buf, size_t count) 57{ 58 struct userspace_consumer_data *data = dev_get_drvdata(dev); 59 bool enabled; 60 int ret; 61 62 /* 63 * sysfs_streq() doesn't need the \n's, but we add them so the strings 64 * will be shared with show_state(), above. 65 */ 66 if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1")) 67 enabled = true; 68 else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0")) 69 enabled = false; 70 else { 71 dev_err(dev, "Configuring invalid mode\n"); 72 return count; 73 } 74 75 mutex_lock(&data->lock); 76 if (enabled != data->enabled) { 77 if (enabled) 78 ret = regulator_bulk_enable(data->num_supplies, 79 data->supplies); 80 else 81 ret = regulator_bulk_disable(data->num_supplies, 82 data->supplies); 83 84 if (ret == 0) 85 data->enabled = enabled; 86 else 87 dev_err(dev, "Failed to configure state: %d\n", ret); 88 } 89 mutex_unlock(&data->lock); 90 91 return count; 92} 93 94static DEVICE_ATTR(name, 0444, reg_show_name, NULL); 95static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state); 96 97static struct attribute *attributes[] = { 98 &dev_attr_name.attr, 99 &dev_attr_state.attr, 100 NULL, 101}; 102 103static const struct attribute_group attr_group = { 104 .attrs = attributes, 105}; 106 107static int regulator_userspace_consumer_probe(struct platform_device *pdev) 108{ 109 struct regulator_userspace_consumer_data *pdata; 110 struct userspace_consumer_data *drvdata; 111 int ret; 112 113 pdata = pdev->dev.platform_data; 114 if (!pdata) 115 return -EINVAL; 116 117 drvdata = kzalloc(sizeof(struct userspace_consumer_data), GFP_KERNEL); 118 if (drvdata == NULL) 119 return -ENOMEM; 120 121 drvdata->name = pdata->name; 122 drvdata->num_supplies = pdata->num_supplies; 123 drvdata->supplies = pdata->supplies; 124 125 mutex_init(&drvdata->lock); 126 127 ret = regulator_bulk_get(&pdev->dev, drvdata->num_supplies, 128 drvdata->supplies); 129 if (ret) { 130 dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret); 131 goto err_alloc_supplies; 132 } 133 134 ret = sysfs_create_group(&pdev->dev.kobj, &attr_group); 135 if (ret != 0) 136 goto err_create_attrs; 137 138 if (pdata->init_on) { 139 ret = regulator_bulk_enable(drvdata->num_supplies, 140 drvdata->supplies); 141 if (ret) { 142 dev_err(&pdev->dev, 143 "Failed to set initial state: %d\n", ret); 144 goto err_enable; 145 } 146 } 147 148 drvdata->enabled = pdata->init_on; 149 platform_set_drvdata(pdev, drvdata); 150 151 return 0; 152 153err_enable: 154 sysfs_remove_group(&pdev->dev.kobj, &attr_group); 155 156err_create_attrs: 157 regulator_bulk_free(drvdata->num_supplies, drvdata->supplies); 158 159err_alloc_supplies: 160 kfree(drvdata); 161 return ret; 162} 163 164static int regulator_userspace_consumer_remove(struct platform_device *pdev) 165{ 166 struct userspace_consumer_data *data = platform_get_drvdata(pdev); 167 168 sysfs_remove_group(&pdev->dev.kobj, &attr_group); 169 170 if (data->enabled) 171 regulator_bulk_disable(data->num_supplies, data->supplies); 172 173 regulator_bulk_free(data->num_supplies, data->supplies); 174 kfree(data); 175 176 return 0; 177} 178 179static struct platform_driver regulator_userspace_consumer_driver = { 180 .probe = regulator_userspace_consumer_probe, 181 .remove = regulator_userspace_consumer_remove, 182 .driver = { 183 .name = "reg-userspace-consumer", 184 }, 185}; 186 187 188static int __init regulator_userspace_consumer_init(void) 189{ 190 return platform_driver_register(®ulator_userspace_consumer_driver); 191} 192module_init(regulator_userspace_consumer_init); 193 194static void __exit regulator_userspace_consumer_exit(void) 195{ 196 platform_driver_unregister(®ulator_userspace_consumer_driver); 197} 198module_exit(regulator_userspace_consumer_exit); 199 200MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); 201MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators"); 202MODULE_LICENSE("GPL"); 203