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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * userspace-consumer.c4 *5 * Copyright 2009 CompuLab, Ltd.6 *7 * Author: Mike Rapoport <mike@compulab.co.il>8 *9 * Based of virtual consumer driver:10 * Copyright 2008 Wolfson Microelectronics PLC.11 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>12 */13 14#include <linux/err.h>15#include <linux/mutex.h>16#include <linux/module.h>17#include <linux/of.h>18#include <linux/platform_device.h>19#include <linux/regulator/consumer.h>20#include <linux/regulator/userspace-consumer.h>21#include <linux/slab.h>22 23struct userspace_consumer_data {24 const char *name;25 26 struct mutex lock;27 bool enabled;28 bool no_autoswitch;29 30 int num_supplies;31 struct regulator_bulk_data *supplies;32};33 34static ssize_t name_show(struct device *dev,35 struct device_attribute *attr, char *buf)36{37 struct userspace_consumer_data *data = dev_get_drvdata(dev);38 39 return sprintf(buf, "%s\n", data->name);40}41 42static ssize_t state_show(struct device *dev,43 struct device_attribute *attr, char *buf)44{45 struct userspace_consumer_data *data = dev_get_drvdata(dev);46 47 if (data->enabled)48 return sprintf(buf, "enabled\n");49 50 return sprintf(buf, "disabled\n");51}52 53static ssize_t state_store(struct device *dev, struct device_attribute *attr,54 const char *buf, size_t count)55{56 struct userspace_consumer_data *data = dev_get_drvdata(dev);57 bool enabled;58 int ret;59 60 /*61 * sysfs_streq() doesn't need the \n's, but we add them so the strings62 * will be shared with show_state(), above.63 */64 if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))65 enabled = true;66 else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))67 enabled = false;68 else {69 dev_err(dev, "Configuring invalid mode\n");70 return count;71 }72 73 mutex_lock(&data->lock);74 if (enabled != data->enabled) {75 if (enabled)76 ret = regulator_bulk_enable(data->num_supplies,77 data->supplies);78 else79 ret = regulator_bulk_disable(data->num_supplies,80 data->supplies);81 82 if (ret == 0)83 data->enabled = enabled;84 else85 dev_err(dev, "Failed to configure state: %d\n", ret);86 }87 mutex_unlock(&data->lock);88 89 return count;90}91 92static DEVICE_ATTR_RO(name);93static DEVICE_ATTR_RW(state);94 95static struct attribute *attributes[] = {96 &dev_attr_name.attr,97 &dev_attr_state.attr,98 NULL,99};100 101static umode_t attr_visible(struct kobject *kobj, struct attribute *attr, int idx)102{103 struct device *dev = kobj_to_dev(kobj);104 struct userspace_consumer_data *data = dev_get_drvdata(dev);105 106 /* If a name hasn't been set, don't bother with the attribute */107 if (attr == &dev_attr_name.attr && !data->name)108 return 0;109 110 return attr->mode;111}112 113static const struct attribute_group attr_group = {114 .attrs = attributes,115 .is_visible = attr_visible,116};117 118static int regulator_userspace_consumer_probe(struct platform_device *pdev)119{120 struct regulator_userspace_consumer_data tmpdata;121 struct regulator_userspace_consumer_data *pdata;122 struct userspace_consumer_data *drvdata;123 int ret;124 125 pdata = dev_get_platdata(&pdev->dev);126 if (!pdata) {127 if (!pdev->dev.of_node)128 return -EINVAL;129 130 pdata = &tmpdata;131 memset(pdata, 0, sizeof(*pdata));132 133 pdata->no_autoswitch = true;134 pdata->num_supplies = 1;135 pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);136 if (!pdata->supplies)137 return -ENOMEM;138 pdata->supplies[0].supply = "vout";139 }140 141 if (pdata->num_supplies < 1) {142 dev_err(&pdev->dev, "At least one supply required\n");143 return -EINVAL;144 }145 146 drvdata = devm_kzalloc(&pdev->dev,147 sizeof(struct userspace_consumer_data),148 GFP_KERNEL);149 if (drvdata == NULL)150 return -ENOMEM;151 152 drvdata->name = pdata->name;153 drvdata->num_supplies = pdata->num_supplies;154 drvdata->supplies = pdata->supplies;155 drvdata->no_autoswitch = pdata->no_autoswitch;156 157 mutex_init(&drvdata->lock);158 159 ret = devm_regulator_bulk_get_exclusive(&pdev->dev, drvdata->num_supplies,160 drvdata->supplies);161 if (ret)162 return dev_err_probe(&pdev->dev, ret, "Failed to get supplies\n");163 164 platform_set_drvdata(pdev, drvdata);165 166 ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);167 if (ret != 0)168 return ret;169 170 if (pdata->init_on && !pdata->no_autoswitch) {171 ret = regulator_bulk_enable(drvdata->num_supplies,172 drvdata->supplies);173 if (ret) {174 dev_err(&pdev->dev,175 "Failed to set initial state: %d\n", ret);176 goto err_enable;177 }178 }179 180 ret = regulator_is_enabled(pdata->supplies[0].consumer);181 if (ret < 0) {182 dev_err(&pdev->dev, "Failed to get regulator status\n");183 goto err_enable;184 }185 drvdata->enabled = !!ret;186 187 return 0;188 189err_enable:190 sysfs_remove_group(&pdev->dev.kobj, &attr_group);191 192 return ret;193}194 195static void regulator_userspace_consumer_remove(struct platform_device *pdev)196{197 struct userspace_consumer_data *data = platform_get_drvdata(pdev);198 199 sysfs_remove_group(&pdev->dev.kobj, &attr_group);200 201 if (data->enabled && !data->no_autoswitch)202 regulator_bulk_disable(data->num_supplies, data->supplies);203}204 205static const struct of_device_id regulator_userspace_consumer_of_match[] = {206 { .compatible = "regulator-output", },207 {},208};209MODULE_DEVICE_TABLE(of, regulator_userspace_consumer_of_match);210 211static struct platform_driver regulator_userspace_consumer_driver = {212 .probe = regulator_userspace_consumer_probe,213 .remove_new = regulator_userspace_consumer_remove,214 .driver = {215 .name = "reg-userspace-consumer",216 .probe_type = PROBE_PREFER_ASYNCHRONOUS,217 .of_match_table = regulator_userspace_consumer_of_match,218 },219};220 221module_platform_driver(regulator_userspace_consumer_driver);222 223MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");224MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");225MODULE_LICENSE("GPL");226