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 27 struct 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 37 static 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 45 static 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 56 static 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 95 static DEVICE_ATTR(name, 0444, reg_show_name, NULL); 96 static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state); 97 98 static struct attribute *attributes[] = { 99 &dev_attr_name.attr, 100 &dev_attr_state.attr, 101 NULL, 102 }; 103 104 static const struct attribute_group attr_group = { 105 .attrs = attributes, 106 }; 107 108 static 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 = dev_get_platdata(&pdev->dev); 115 if (!pdata) 116 return -EINVAL; 117 118 drvdata = devm_kzalloc(&pdev->dev, 119 sizeof(struct userspace_consumer_data), 120 GFP_KERNEL); 121 if (drvdata == NULL) 122 return -ENOMEM; 123 124 drvdata->name = pdata->name; 125 drvdata->num_supplies = pdata->num_supplies; 126 drvdata->supplies = pdata->supplies; 127 128 mutex_init(&drvdata->lock); 129 130 ret = devm_regulator_bulk_get(&pdev->dev, drvdata->num_supplies, 131 drvdata->supplies); 132 if (ret) { 133 dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret); 134 return ret; 135 } 136 137 ret = sysfs_create_group(&pdev->dev.kobj, &attr_group); 138 if (ret != 0) 139 return ret; 140 141 if (pdata->init_on) { 142 ret = regulator_bulk_enable(drvdata->num_supplies, 143 drvdata->supplies); 144 if (ret) { 145 dev_err(&pdev->dev, 146 "Failed to set initial state: %d\n", ret); 147 goto err_enable; 148 } 149 } 150 151 drvdata->enabled = pdata->init_on; 152 platform_set_drvdata(pdev, drvdata); 153 154 return 0; 155 156 err_enable: 157 sysfs_remove_group(&pdev->dev.kobj, &attr_group); 158 159 return ret; 160 } 161 162 static int regulator_userspace_consumer_remove(struct platform_device *pdev) 163 { 164 struct userspace_consumer_data *data = platform_get_drvdata(pdev); 165 166 sysfs_remove_group(&pdev->dev.kobj, &attr_group); 167 168 if (data->enabled) 169 regulator_bulk_disable(data->num_supplies, data->supplies); 170 171 return 0; 172 } 173 174 static struct platform_driver regulator_userspace_consumer_driver = { 175 .probe = regulator_userspace_consumer_probe, 176 .remove = regulator_userspace_consumer_remove, 177 .driver = { 178 .name = "reg-userspace-consumer", 179 }, 180 }; 181 182 module_platform_driver(regulator_userspace_consumer_driver); 183 184 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); 185 MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators"); 186 MODULE_LICENSE("GPL"); 187