drivers/regulator/userspace-consumer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * userspace-consumer.c
   4  *
   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
  23 struct 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
  34 static 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
  42 static 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
  53 static 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 strings
  62          * 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                 else
  79                         ret = regulator_bulk_disable(data->num_supplies,
  80                                                      data->supplies);
  81
  82                 if (ret == 0)
  83                         data->enabled = enabled;
  84                 else
  85                         dev_err(dev, "Failed to configure state: %d\n", ret);
  86         }
  87         mutex_unlock(&data->lock);
  88
  89         return count;
  90 }
  91
  92 static DEVICE_ATTR_RO(name);
  93 static DEVICE_ATTR_RW(state);
  94
  95 static struct attribute *attributes[] = {
  96         &dev_attr_name.attr,
  97         &dev_attr_state.attr,
  98         NULL,
  99 };
 100
 101 static 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
 113 static const struct attribute_group attr_group = {
 114         .attrs  = attributes,
 115         .is_visible =  attr_visible,
 116 };
 117
 118 static 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
 189 err_enable:
 190         sysfs_remove_group(&pdev->dev.kobj, &attr_group);
 191
 192         return ret;
 193 }
 194
 195 static 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
 205 static const struct of_device_id regulator_userspace_consumer_of_match[] = {
 206         { .compatible = "regulator-output", },
 207         {},
 208 };
 209 MODULE_DEVICE_TABLE(of, regulator_userspace_consumer_of_match);
 210
 211 static struct platform_driver regulator_userspace_consumer_driver = {
 212         .probe          = regulator_userspace_consumer_probe,
 213         .remove         = 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
 221 module_platform_driver(regulator_userspace_consumer_driver);
 222
 223 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
 224 MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
 225 MODULE_LICENSE("GPL");