drivers/power/supply/power_supply_hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  power_supply_hwmon.c - power supply hwmon support.
   4  */
   5
   6 #include <linux/err.h>
   7 #include <linux/hwmon.h>
   8 #include <linux/power_supply.h>
   9 #include <linux/slab.h>
  10
  11 struct power_supply_hwmon {
  12         struct power_supply *psy;
  13         unsigned long *props;
  14 };
  15
  16 static const char *const ps_temp_label[] = {
  17         "temp",
  18         "ambient temp",
  19 };
  20
  21 static int power_supply_hwmon_in_to_property(u32 attr)
  22 {
  23         switch (attr) {
  24         case hwmon_in_average:
  25                 return POWER_SUPPLY_PROP_VOLTAGE_AVG;
  26         case hwmon_in_min:
  27                 return POWER_SUPPLY_PROP_VOLTAGE_MIN;
  28         case hwmon_in_max:
  29                 return POWER_SUPPLY_PROP_VOLTAGE_MAX;
  30         case hwmon_in_input:
  31                 return POWER_SUPPLY_PROP_VOLTAGE_NOW;
  32         default:
  33                 return -EINVAL;
  34         }
  35 }
  36
  37 static int power_supply_hwmon_curr_to_property(u32 attr)
  38 {
  39         switch (attr) {
  40         case hwmon_curr_average:
  41                 return POWER_SUPPLY_PROP_CURRENT_AVG;
  42         case hwmon_curr_max:
  43                 return POWER_SUPPLY_PROP_CURRENT_MAX;
  44         case hwmon_curr_input:
  45                 return POWER_SUPPLY_PROP_CURRENT_NOW;
  46         default:
  47                 return -EINVAL;
  48         }
  49 }
  50
  51 static int power_supply_hwmon_temp_to_property(u32 attr, int channel)
  52 {
  53         if (channel) {
  54                 switch (attr) {
  55                 case hwmon_temp_input:
  56                         return POWER_SUPPLY_PROP_TEMP_AMBIENT;
  57                 case hwmon_temp_min_alarm:
  58                         return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN;
  59                 case hwmon_temp_max_alarm:
  60                         return POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX;
  61                 default:
  62                         break;
  63                 }
  64         } else {
  65                 switch (attr) {
  66                 case hwmon_temp_input:
  67                         return POWER_SUPPLY_PROP_TEMP;
  68                 case hwmon_temp_max:
  69                         return POWER_SUPPLY_PROP_TEMP_MAX;
  70                 case hwmon_temp_min:
  71                         return POWER_SUPPLY_PROP_TEMP_MIN;
  72                 case hwmon_temp_min_alarm:
  73                         return POWER_SUPPLY_PROP_TEMP_ALERT_MIN;
  74                 case hwmon_temp_max_alarm:
  75                         return POWER_SUPPLY_PROP_TEMP_ALERT_MAX;
  76                 default:
  77                         break;
  78                 }
  79         }
  80
  81         return -EINVAL;
  82 }
  83
  84 static int
  85 power_supply_hwmon_to_property(enum hwmon_sensor_types type,
  86                                u32 attr, int channel)
  87 {
  88         switch (type) {
  89         case hwmon_in:
  90                 return power_supply_hwmon_in_to_property(attr);
  91         case hwmon_curr:
  92                 return power_supply_hwmon_curr_to_property(attr);
  93         case hwmon_temp:
  94                 return power_supply_hwmon_temp_to_property(attr, channel);
  95         default:
  96                 return -EINVAL;
  97         }
  98 }
  99
 100 static bool power_supply_hwmon_is_a_label(enum hwmon_sensor_types type,
 101                                            u32 attr)
 102 {
 103         return type == hwmon_temp && attr == hwmon_temp_label;
 104 }
 105
 106 struct hwmon_type_attr_list {
 107         const u32 *attrs;
 108         size_t n_attrs;
 109 };
 110
 111 static const u32 ps_temp_attrs[] = {
 112         hwmon_temp_input,
 113         hwmon_temp_min, hwmon_temp_max,
 114         hwmon_temp_min_alarm, hwmon_temp_max_alarm,
 115 };
 116
 117 static const struct hwmon_type_attr_list ps_type_attrs[hwmon_max] = {
 118         [hwmon_temp] = { ps_temp_attrs, ARRAY_SIZE(ps_temp_attrs) },
 119 };
 120
 121 static bool power_supply_hwmon_has_input(
 122         const struct power_supply_hwmon *psyhw,
 123         enum hwmon_sensor_types type, int channel)
 124 {
 125         const struct hwmon_type_attr_list *attr_list = &ps_type_attrs[type];
 126         size_t i;
 127
 128         for (i = 0; i < attr_list->n_attrs; ++i) {
 129                 int prop = power_supply_hwmon_to_property(type,
 130                         attr_list->attrs[i], channel);
 131
 132                 if (prop >= 0 && test_bit(prop, psyhw->props))
 133                         return true;
 134         }
 135
 136         return false;
 137 }
 138
 139 static bool power_supply_hwmon_is_writable(enum hwmon_sensor_types type,
 140                                            u32 attr)
 141 {
 142         switch (type) {
 143         case hwmon_in:
 144                 return attr == hwmon_in_min ||
 145                        attr == hwmon_in_max;
 146         case hwmon_curr:
 147                 return attr == hwmon_curr_max;
 148         case hwmon_temp:
 149                 return attr == hwmon_temp_max ||
 150                        attr == hwmon_temp_min ||
 151                        attr == hwmon_temp_min_alarm ||
 152                        attr == hwmon_temp_max_alarm;
 153         default:
 154                 return false;
 155         }
 156 }
 157
 158 static umode_t power_supply_hwmon_is_visible(const void *data,
 159                                              enum hwmon_sensor_types type,
 160                                              u32 attr, int channel)
 161 {
 162         const struct power_supply_hwmon *psyhw = data;
 163         int prop;
 164
 165         if (power_supply_hwmon_is_a_label(type, attr)) {
 166                 if (power_supply_hwmon_has_input(psyhw, type, channel))
 167                         return 0444;
 168                 else
 169                         return 0;
 170         }
 171
 172         prop = power_supply_hwmon_to_property(type, attr, channel);
 173         if (prop < 0 || !test_bit(prop, psyhw->props))
 174                 return 0;
 175
 176         if (power_supply_property_is_writeable(psyhw->psy, prop) > 0 &&
 177             power_supply_hwmon_is_writable(type, attr))
 178                 return 0644;
 179
 180         return 0444;
 181 }
 182
 183 static int power_supply_hwmon_read_string(struct device *dev,
 184                                           enum hwmon_sensor_types type,
 185                                           u32 attr, int channel,
 186                                           const char **str)
 187 {
 188         switch (type) {
 189         case hwmon_temp:
 190                 *str = ps_temp_label[channel];
 191                 break;
 192         default:
 193                 /* unreachable, but see:
 194                  * gcc bug #51513 [1] and clang bug #978 [2]
 195                  *
 196                  * [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51513
 197                  * [2] https://github.com/ClangBuiltLinux/linux/issues/978
 198                  */
 199                 break;
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int
 206 power_supply_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 207                         u32 attr, int channel, long *val)
 208 {
 209         struct power_supply_hwmon *psyhw = dev_get_drvdata(dev);
 210         struct power_supply *psy = psyhw->psy;
 211         union power_supply_propval pspval;
 212         int ret, prop;
 213
 214         prop = power_supply_hwmon_to_property(type, attr, channel);
 215         if (prop < 0)
 216                 return prop;
 217
 218         ret  = power_supply_get_property(psy, prop, &pspval);
 219         if (ret)
 220                 return ret;
 221
 222         switch (type) {
 223         /*
 224          * Both voltage and current is reported in units of
 225          * microvolts/microamps, so we need to adjust it to
 226          * milliamps(volts)
 227          */
 228         case hwmon_curr:
 229         case hwmon_in:
 230                 pspval.intval = DIV_ROUND_CLOSEST(pspval.intval, 1000);
 231                 break;
 232         /*
 233          * Temp needs to be converted from 1/10 C to milli-C
 234          */
 235         case hwmon_temp:
 236                 if (check_mul_overflow(pspval.intval, 100,
 237                                        &pspval.intval))
 238                         return -EOVERFLOW;
 239                 break;
 240         default:
 241                 return -EINVAL;
 242         }
 243
 244         *val = pspval.intval;
 245
 246         return 0;
 247 }
 248
 249 static int
 250 power_supply_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
 251                          u32 attr, int channel, long val)
 252 {
 253         struct power_supply_hwmon *psyhw = dev_get_drvdata(dev);
 254         struct power_supply *psy = psyhw->psy;
 255         union power_supply_propval pspval;
 256         int prop;
 257
 258         prop = power_supply_hwmon_to_property(type, attr, channel);
 259         if (prop < 0)
 260                 return prop;
 261
 262         pspval.intval = val;
 263
 264         switch (type) {
 265         /*
 266          * Both voltage and current is reported in units of
 267          * microvolts/microamps, so we need to adjust it to
 268          * milliamps(volts)
 269          */
 270         case hwmon_curr:
 271         case hwmon_in:
 272                 if (check_mul_overflow(pspval.intval, 1000,
 273                                        &pspval.intval))
 274                         return -EOVERFLOW;
 275                 break;
 276         /*
 277          * Temp needs to be converted from 1/10 C to milli-C
 278          */
 279         case hwmon_temp:
 280                 pspval.intval = DIV_ROUND_CLOSEST(pspval.intval, 100);
 281                 break;
 282         default:
 283                 return -EINVAL;
 284         }
 285
 286         return power_supply_set_property(psy, prop, &pspval);
 287 }
 288
 289 static const struct hwmon_ops power_supply_hwmon_ops = {
 290         .is_visible     = power_supply_hwmon_is_visible,
 291         .read           = power_supply_hwmon_read,
 292         .write          = power_supply_hwmon_write,
 293         .read_string    = power_supply_hwmon_read_string,
 294 };
 295
 296 static const struct hwmon_channel_info *power_supply_hwmon_info[] = {
 297         HWMON_CHANNEL_INFO(temp,
 298                            HWMON_T_LABEL     |
 299                            HWMON_T_INPUT     |
 300                            HWMON_T_MAX       |
 301                            HWMON_T_MIN       |
 302                            HWMON_T_MIN_ALARM,
 303
 304                            HWMON_T_LABEL     |
 305                            HWMON_T_INPUT     |
 306                            HWMON_T_MIN_ALARM |
 307                            HWMON_T_MAX_ALARM),
 308
 309         HWMON_CHANNEL_INFO(curr,
 310                            HWMON_C_AVERAGE |
 311                            HWMON_C_MAX     |
 312                            HWMON_C_INPUT),
 313
 314         HWMON_CHANNEL_INFO(in,
 315                            HWMON_I_AVERAGE |
 316                            HWMON_I_MIN     |
 317                            HWMON_I_MAX     |
 318                            HWMON_I_INPUT),
 319         NULL
 320 };
 321
 322 static const struct hwmon_chip_info power_supply_hwmon_chip_info = {
 323         .ops = &power_supply_hwmon_ops,
 324         .info = power_supply_hwmon_info,
 325 };
 326
 327 int power_supply_add_hwmon_sysfs(struct power_supply *psy)
 328 {
 329         const struct power_supply_desc *desc = psy->desc;
 330         struct power_supply_hwmon *psyhw;
 331         struct device *dev = &psy->dev;
 332         struct device *hwmon;
 333         int ret, i;
 334         const char *name;
 335
 336         if (!devres_open_group(dev, power_supply_add_hwmon_sysfs,
 337                                GFP_KERNEL))
 338                 return -ENOMEM;
 339
 340         psyhw = devm_kzalloc(dev, sizeof(*psyhw), GFP_KERNEL);
 341         if (!psyhw) {
 342                 ret = -ENOMEM;
 343                 goto error;
 344         }
 345
 346         psyhw->psy = psy;
 347         psyhw->props = devm_bitmap_zalloc(dev,
 348                                           POWER_SUPPLY_PROP_TIME_TO_FULL_AVG + 1,
 349                                           GFP_KERNEL);
 350         if (!psyhw->props) {
 351                 ret = -ENOMEM;
 352                 goto error;
 353         }
 354
 355         for (i = 0; i < desc->num_properties; i++) {
 356                 const enum power_supply_property prop = desc->properties[i];
 357
 358                 switch (prop) {
 359                 case POWER_SUPPLY_PROP_CURRENT_AVG:
 360                 case POWER_SUPPLY_PROP_CURRENT_MAX:
 361                 case POWER_SUPPLY_PROP_CURRENT_NOW:
 362                 case POWER_SUPPLY_PROP_TEMP:
 363                 case POWER_SUPPLY_PROP_TEMP_MAX:
 364                 case POWER_SUPPLY_PROP_TEMP_MIN:
 365                 case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
 366                 case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
 367                 case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 368                 case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MIN:
 369                 case POWER_SUPPLY_PROP_TEMP_AMBIENT_ALERT_MAX:
 370                 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 371                 case POWER_SUPPLY_PROP_VOLTAGE_MIN:
 372                 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
 373                 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 374                         set_bit(prop, psyhw->props);
 375                         break;
 376                 default:
 377                         break;
 378                 }
 379         }
 380
 381         name = psy->desc->name;
 382         if (strchr(name, '-')) {
 383                 char *new_name;
 384
 385                 new_name = devm_kstrdup(dev, name, GFP_KERNEL);
 386                 if (!new_name) {
 387                         ret = -ENOMEM;
 388                         goto error;
 389                 }
 390                 strreplace(new_name, '-', '_');
 391                 name = new_name;
 392         }
 393         hwmon = devm_hwmon_device_register_with_info(dev, name,
 394                                                 psyhw,
 395                                                 &power_supply_hwmon_chip_info,
 396                                                 NULL);
 397         ret = PTR_ERR_OR_ZERO(hwmon);
 398         if (ret)
 399                 goto error;
 400
 401         devres_close_group(dev, power_supply_add_hwmon_sysfs);
 402         return 0;
 403 error:
 404         devres_release_group(dev, NULL);
 405         return ret;
 406 }
 407
 408 void power_supply_remove_hwmon_sysfs(struct power_supply *psy)
 409 {
 410         devres_release_group(&psy->dev, power_supply_add_hwmon_sysfs);
 411 }