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