drivers/regulator/virtual.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * reg-virtual-consumer.c
   4  *
   5  * Copyright 2008 Wolfson Microelectronics PLC.
   6  *
   7  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/mutex.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/regulator/consumer.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16
  17 struct virtual_consumer_data {
  18         struct mutex lock;
  19         struct regulator *regulator;
  20         bool enabled;
  21         int min_uV;
  22         int max_uV;
  23         int min_uA;
  24         int max_uA;
  25         unsigned int mode;
  26 };
  27
  28 static void update_voltage_constraints(struct device *dev,
  29                                        struct virtual_consumer_data *data)
  30 {
  31         int ret;
  32
  33         if (data->min_uV && data->max_uV
  34             && data->min_uV <= data->max_uV) {
  35                 dev_dbg(dev, "Requesting %d-%duV\n",
  36                         data->min_uV, data->max_uV);
  37                 ret = regulator_set_voltage(data->regulator,
  38                                         data->min_uV, data->max_uV);
  39                 if (ret != 0) {
  40                         dev_err(dev,
  41                                 "regulator_set_voltage() failed: %d\n", ret);
  42                         return;
  43                 }
  44         }
  45
  46         if (data->min_uV && data->max_uV && !data->enabled) {
  47                 dev_dbg(dev, "Enabling regulator\n");
  48                 ret = regulator_enable(data->regulator);
  49                 if (ret == 0)
  50                         data->enabled = true;
  51                 else
  52                         dev_err(dev, "regulator_enable() failed: %d\n",
  53                                 ret);
  54         }
  55
  56         if (!(data->min_uV && data->max_uV) && data->enabled) {
  57                 dev_dbg(dev, "Disabling regulator\n");
  58                 ret = regulator_disable(data->regulator);
  59                 if (ret == 0)
  60                         data->enabled = false;
  61                 else
  62                         dev_err(dev, "regulator_disable() failed: %d\n",
  63                                 ret);
  64         }
  65 }
  66
  67 static void update_current_limit_constraints(struct device *dev,
  68                                           struct virtual_consumer_data *data)
  69 {
  70         int ret;
  71
  72         if (data->max_uA
  73             && data->min_uA <= data->max_uA) {
  74                 dev_dbg(dev, "Requesting %d-%duA\n",
  75                         data->min_uA, data->max_uA);
  76                 ret = regulator_set_current_limit(data->regulator,
  77                                         data->min_uA, data->max_uA);
  78                 if (ret != 0) {
  79                         dev_err(dev,
  80                                 "regulator_set_current_limit() failed: %d\n",
  81                                 ret);
  82                         return;
  83                 }
  84         }
  85
  86         if (data->max_uA && !data->enabled) {
  87                 dev_dbg(dev, "Enabling regulator\n");
  88                 ret = regulator_enable(data->regulator);
  89                 if (ret == 0)
  90                         data->enabled = true;
  91                 else
  92                         dev_err(dev, "regulator_enable() failed: %d\n",
  93                                 ret);
  94         }
  95
  96         if (!(data->min_uA && data->max_uA) && data->enabled) {
  97                 dev_dbg(dev, "Disabling regulator\n");
  98                 ret = regulator_disable(data->regulator);
  99                 if (ret == 0)
 100                         data->enabled = false;
 101                 else
 102                         dev_err(dev, "regulator_disable() failed: %d\n",
 103                                 ret);
 104         }
 105 }
 106
 107 static ssize_t show_min_uV(struct device *dev,
 108                            struct device_attribute *attr, char *buf)
 109 {
 110         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 111         return sprintf(buf, "%d\n", data->min_uV);
 112 }
 113
 114 static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
 115                           const char *buf, size_t count)
 116 {
 117         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 118         long val;
 119
 120         if (kstrtol(buf, 10, &val) != 0)
 121                 return count;
 122
 123         mutex_lock(&data->lock);
 124
 125         data->min_uV = val;
 126         update_voltage_constraints(dev, data);
 127
 128         mutex_unlock(&data->lock);
 129
 130         return count;
 131 }
 132
 133 static ssize_t show_max_uV(struct device *dev,
 134                            struct device_attribute *attr, char *buf)
 135 {
 136         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 137         return sprintf(buf, "%d\n", data->max_uV);
 138 }
 139
 140 static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
 141                           const char *buf, size_t count)
 142 {
 143         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 144         long val;
 145
 146         if (kstrtol(buf, 10, &val) != 0)
 147                 return count;
 148
 149         mutex_lock(&data->lock);
 150
 151         data->max_uV = val;
 152         update_voltage_constraints(dev, data);
 153
 154         mutex_unlock(&data->lock);
 155
 156         return count;
 157 }
 158
 159 static ssize_t show_min_uA(struct device *dev,
 160                            struct device_attribute *attr, char *buf)
 161 {
 162         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 163         return sprintf(buf, "%d\n", data->min_uA);
 164 }
 165
 166 static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
 167                           const char *buf, size_t count)
 168 {
 169         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 170         long val;
 171
 172         if (kstrtol(buf, 10, &val) != 0)
 173                 return count;
 174
 175         mutex_lock(&data->lock);
 176
 177         data->min_uA = val;
 178         update_current_limit_constraints(dev, data);
 179
 180         mutex_unlock(&data->lock);
 181
 182         return count;
 183 }
 184
 185 static ssize_t show_max_uA(struct device *dev,
 186                            struct device_attribute *attr, char *buf)
 187 {
 188         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 189         return sprintf(buf, "%d\n", data->max_uA);
 190 }
 191
 192 static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
 193                           const char *buf, size_t count)
 194 {
 195         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 196         long val;
 197
 198         if (kstrtol(buf, 10, &val) != 0)
 199                 return count;
 200
 201         mutex_lock(&data->lock);
 202
 203         data->max_uA = val;
 204         update_current_limit_constraints(dev, data);
 205
 206         mutex_unlock(&data->lock);
 207
 208         return count;
 209 }
 210
 211 static ssize_t show_mode(struct device *dev,
 212                          struct device_attribute *attr, char *buf)
 213 {
 214         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 215
 216         switch (data->mode) {
 217         case REGULATOR_MODE_FAST:
 218                 return sprintf(buf, "fast\n");
 219         case REGULATOR_MODE_NORMAL:
 220                 return sprintf(buf, "normal\n");
 221         case REGULATOR_MODE_IDLE:
 222                 return sprintf(buf, "idle\n");
 223         case REGULATOR_MODE_STANDBY:
 224                 return sprintf(buf, "standby\n");
 225         default:
 226                 return sprintf(buf, "unknown\n");
 227         }
 228 }
 229
 230 static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
 231                         const char *buf, size_t count)
 232 {
 233         struct virtual_consumer_data *data = dev_get_drvdata(dev);
 234         unsigned int mode;
 235         int ret;
 236
 237         /*
 238          * sysfs_streq() doesn't need the \n's, but we add them so the strings
 239          * will be shared with show_mode(), above.
 240          */
 241         if (sysfs_streq(buf, "fast\n"))
 242                 mode = REGULATOR_MODE_FAST;
 243         else if (sysfs_streq(buf, "normal\n"))
 244                 mode = REGULATOR_MODE_NORMAL;
 245         else if (sysfs_streq(buf, "idle\n"))
 246                 mode = REGULATOR_MODE_IDLE;
 247         else if (sysfs_streq(buf, "standby\n"))
 248                 mode = REGULATOR_MODE_STANDBY;
 249         else {
 250                 dev_err(dev, "Configuring invalid mode\n");
 251                 return count;
 252         }
 253
 254         mutex_lock(&data->lock);
 255         ret = regulator_set_mode(data->regulator, mode);
 256         if (ret == 0)
 257                 data->mode = mode;
 258         else
 259                 dev_err(dev, "Failed to configure mode: %d\n", ret);
 260         mutex_unlock(&data->lock);
 261
 262         return count;
 263 }
 264
 265 static DEVICE_ATTR(min_microvolts, 0664, show_min_uV, set_min_uV);
 266 static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV);
 267 static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA);
 268 static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA);
 269 static DEVICE_ATTR(mode, 0664, show_mode, set_mode);
 270
 271 static struct attribute *regulator_virtual_attributes[] = {
 272         &dev_attr_min_microvolts.attr,
 273         &dev_attr_max_microvolts.attr,
 274         &dev_attr_min_microamps.attr,
 275         &dev_attr_max_microamps.attr,
 276         &dev_attr_mode.attr,
 277         NULL
 278 };
 279
 280 static const struct attribute_group regulator_virtual_attr_group = {
 281         .attrs  = regulator_virtual_attributes,
 282 };
 283
 284 static int regulator_virtual_probe(struct platform_device *pdev)
 285 {
 286         char *reg_id = dev_get_platdata(&pdev->dev);
 287         struct virtual_consumer_data *drvdata;
 288         int ret;
 289
 290         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
 291                                GFP_KERNEL);
 292         if (drvdata == NULL)
 293                 return -ENOMEM;
 294
 295         mutex_init(&drvdata->lock);
 296
 297         drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
 298         if (IS_ERR(drvdata->regulator)) {
 299                 ret = PTR_ERR(drvdata->regulator);
 300                 dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n",
 301                         reg_id, ret);
 302                 return ret;
 303         }
 304
 305         ret = sysfs_create_group(&pdev->dev.kobj,
 306                                  &regulator_virtual_attr_group);
 307         if (ret != 0) {
 308                 dev_err(&pdev->dev,
 309                         "Failed to create attribute group: %d\n", ret);
 310                 return ret;
 311         }
 312
 313         drvdata->mode = regulator_get_mode(drvdata->regulator);
 314
 315         platform_set_drvdata(pdev, drvdata);
 316
 317         return 0;
 318 }
 319
 320 static int regulator_virtual_remove(struct platform_device *pdev)
 321 {
 322         struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
 323
 324         sysfs_remove_group(&pdev->dev.kobj, &regulator_virtual_attr_group);
 325
 326         if (drvdata->enabled)
 327                 regulator_disable(drvdata->regulator);
 328
 329         return 0;
 330 }
 331
 332 static struct platform_driver regulator_virtual_consumer_driver = {
 333         .probe          = regulator_virtual_probe,
 334         .remove         = regulator_virtual_remove,
 335         .driver         = {
 336                 .name           = "reg-virt-consumer",
 337         },
 338 };
 339
 340 module_platform_driver(regulator_virtual_consumer_driver);
 341
 342 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 343 MODULE_DESCRIPTION("Virtual regulator consumer");
 344 MODULE_LICENSE("GPL");
 345 MODULE_ALIAS("platform:reg-virt-consumer");