drivers/hwmon/max31827.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * max31827.c - Support for Maxim Low-Power Switch
   4  *
   5  * Copyright (c) 2023 Daniel Matyas <daniel.matyas@analog.com>
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/bitops.h>
  10 #include <linux/delay.h>
  11 #include <linux/hwmon.h>
  12 #include <linux/i2c.h>
  13 #include <linux/mutex.h>
  14 #include <linux/of_device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/regulator/consumer.h>
  17
  18 #define MAX31827_T_REG                  0x0
  19 #define MAX31827_CONFIGURATION_REG      0x2
  20 #define MAX31827_TH_REG                 0x4
  21 #define MAX31827_TL_REG                 0x6
  22 #define MAX31827_TH_HYST_REG            0x8
  23 #define MAX31827_TL_HYST_REG            0xA
  24
  25 #define MAX31827_CONFIGURATION_1SHOT_MASK       BIT(0)
  26 #define MAX31827_CONFIGURATION_CNV_RATE_MASK    GENMASK(3, 1)
  27 #define MAX31827_CONFIGURATION_PEC_EN_MASK      BIT(4)
  28 #define MAX31827_CONFIGURATION_TIMEOUT_MASK     BIT(5)
  29 #define MAX31827_CONFIGURATION_RESOLUTION_MASK  GENMASK(7, 6)
  30 #define MAX31827_CONFIGURATION_ALRM_POL_MASK    BIT(8)
  31 #define MAX31827_CONFIGURATION_COMP_INT_MASK    BIT(9)
  32 #define MAX31827_CONFIGURATION_FLT_Q_MASK       GENMASK(11, 10)
  33 #define MAX31827_CONFIGURATION_U_TEMP_STAT_MASK BIT(14)
  34 #define MAX31827_CONFIGURATION_O_TEMP_STAT_MASK BIT(15)
  35
  36 #define MAX31827_ALRM_POL_LOW   0x0
  37 #define MAX31827_ALRM_POL_HIGH  0x1
  38 #define MAX31827_FLT_Q_1        0x0
  39 #define MAX31827_FLT_Q_4        0x2
  40
  41 #define MAX31827_8_BIT_CNV_TIME         9
  42 #define MAX31827_9_BIT_CNV_TIME         18
  43 #define MAX31827_10_BIT_CNV_TIME        35
  44 #define MAX31827_12_BIT_CNV_TIME        140
  45
  46 #define MAX31827_16_BIT_TO_M_DGR(x)     (sign_extend32(x, 15) * 1000 / 16)
  47 #define MAX31827_M_DGR_TO_16_BIT(x)     (((x) << 4) / 1000)
  48 #define MAX31827_DEVICE_ENABLE(x)       ((x) ? 0xA : 0x0)
  49
  50 /*
  51  * The enum passed in the .data pointer of struct of_device_id must
  52  * start with a value != 0 since that is a requirement for using
  53  * device_get_match_data().
  54  */
  55 enum chips { max31827 = 1, max31828, max31829 };
  56
  57 enum max31827_cnv {
  58         MAX31827_CNV_1_DIV_64_HZ = 1,
  59         MAX31827_CNV_1_DIV_32_HZ,
  60         MAX31827_CNV_1_DIV_16_HZ,
  61         MAX31827_CNV_1_DIV_4_HZ,
  62         MAX31827_CNV_1_HZ,
  63         MAX31827_CNV_4_HZ,
  64         MAX31827_CNV_8_HZ,
  65 };
  66
  67 static const u16 max31827_conversions[] = {
  68         [MAX31827_CNV_1_DIV_64_HZ] = 64000,
  69         [MAX31827_CNV_1_DIV_32_HZ] = 32000,
  70         [MAX31827_CNV_1_DIV_16_HZ] = 16000,
  71         [MAX31827_CNV_1_DIV_4_HZ] = 4000,
  72         [MAX31827_CNV_1_HZ] = 1000,
  73         [MAX31827_CNV_4_HZ] = 250,
  74         [MAX31827_CNV_8_HZ] = 125,
  75 };
  76
  77 enum max31827_resolution {
  78         MAX31827_RES_8_BIT = 0,
  79         MAX31827_RES_9_BIT,
  80         MAX31827_RES_10_BIT,
  81         MAX31827_RES_12_BIT,
  82 };
  83
  84 static const u16 max31827_resolutions[] = {
  85         [MAX31827_RES_8_BIT] = 1000,
  86         [MAX31827_RES_9_BIT] = 500,
  87         [MAX31827_RES_10_BIT] = 250,
  88         [MAX31827_RES_12_BIT] = 62,
  89 };
  90
  91 static const u16 max31827_conv_times[] = {
  92         [MAX31827_RES_8_BIT] = MAX31827_8_BIT_CNV_TIME,
  93         [MAX31827_RES_9_BIT] = MAX31827_9_BIT_CNV_TIME,
  94         [MAX31827_RES_10_BIT] = MAX31827_10_BIT_CNV_TIME,
  95         [MAX31827_RES_12_BIT] = MAX31827_12_BIT_CNV_TIME,
  96 };
  97
  98 struct max31827_state {
  99         /*
 100          * Prevent simultaneous access to the i2c client.
 101          */
 102         struct mutex lock;
 103         struct regmap *regmap;
 104         bool enable;
 105         unsigned int resolution;
 106         unsigned int update_interval;
 107 };
 108
 109 static const struct regmap_config max31827_regmap = {
 110         .reg_bits = 8,
 111         .val_bits = 16,
 112         .max_register = 0xA,
 113 };
 114
 115 static int shutdown_write(struct max31827_state *st, unsigned int reg,
 116                           unsigned int mask, unsigned int val)
 117 {
 118         unsigned int cfg;
 119         unsigned int cnv_rate;
 120         int ret;
 121
 122         /*
 123          * Before the Temperature Threshold Alarm, Alarm Hysteresis Threshold
 124          * and Resolution bits from Configuration register are changed over I2C,
 125          * the part must be in shutdown mode.
 126          *
 127          * Mutex is used to ensure, that some other process doesn't change the
 128          * configuration register.
 129          */
 130         mutex_lock(&st->lock);
 131
 132         if (!st->enable) {
 133                 if (!mask)
 134                         ret = regmap_write(st->regmap, reg, val);
 135                 else
 136                         ret = regmap_update_bits(st->regmap, reg, mask, val);
 137                 goto unlock;
 138         }
 139
 140         ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &cfg);
 141         if (ret)
 142                 goto unlock;
 143
 144         cnv_rate = MAX31827_CONFIGURATION_CNV_RATE_MASK & cfg;
 145         cfg = cfg & ~(MAX31827_CONFIGURATION_1SHOT_MASK |
 146                       MAX31827_CONFIGURATION_CNV_RATE_MASK);
 147         ret = regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, cfg);
 148         if (ret)
 149                 goto unlock;
 150
 151         if (!mask)
 152                 ret = regmap_write(st->regmap, reg, val);
 153         else
 154                 ret = regmap_update_bits(st->regmap, reg, mask, val);
 155
 156         if (ret)
 157                 goto unlock;
 158
 159         ret = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
 160                                  MAX31827_CONFIGURATION_CNV_RATE_MASK,
 161                                  cnv_rate);
 162
 163 unlock:
 164         mutex_unlock(&st->lock);
 165         return ret;
 166 }
 167
 168 static int write_alarm_val(struct max31827_state *st, unsigned int reg,
 169                            long val)
 170 {
 171         val = MAX31827_M_DGR_TO_16_BIT(val);
 172
 173         return shutdown_write(st, reg, 0, val);
 174 }
 175
 176 static umode_t max31827_is_visible(const void *state,
 177                                    enum hwmon_sensor_types type, u32 attr,
 178                                    int channel)
 179 {
 180         if (type == hwmon_temp) {
 181                 switch (attr) {
 182                 case hwmon_temp_enable:
 183                 case hwmon_temp_max:
 184                 case hwmon_temp_min:
 185                 case hwmon_temp_max_hyst:
 186                 case hwmon_temp_min_hyst:
 187                         return 0644;
 188                 case hwmon_temp_input:
 189                 case hwmon_temp_min_alarm:
 190                 case hwmon_temp_max_alarm:
 191                         return 0444;
 192                 default:
 193                         return 0;
 194                 }
 195         } else if (type == hwmon_chip) {
 196                 if (attr == hwmon_chip_update_interval)
 197                         return 0644;
 198         }
 199
 200         return 0;
 201 }
 202
 203 static int max31827_read(struct device *dev, enum hwmon_sensor_types type,
 204                          u32 attr, int channel, long *val)
 205 {
 206         struct max31827_state *st = dev_get_drvdata(dev);
 207         unsigned int uval;
 208         int ret = 0;
 209
 210         switch (type) {
 211         case hwmon_temp:
 212                 switch (attr) {
 213                 case hwmon_temp_enable:
 214                         ret = regmap_read(st->regmap,
 215                                           MAX31827_CONFIGURATION_REG, &uval);
 216                         if (ret)
 217                                 break;
 218
 219                         uval = FIELD_GET(MAX31827_CONFIGURATION_1SHOT_MASK |
 220                                          MAX31827_CONFIGURATION_CNV_RATE_MASK,
 221                                          uval);
 222                         *val = !!uval;
 223
 224                         break;
 225                 case hwmon_temp_input:
 226                         mutex_lock(&st->lock);
 227
 228                         if (!st->enable) {
 229                                 /*
 230                                  * This operation requires mutex protection,
 231                                  * because the chip configuration should not
 232                                  * be changed during the conversion process.
 233                                  */
 234
 235                                 ret = regmap_update_bits(st->regmap,
 236                                                          MAX31827_CONFIGURATION_REG,
 237                                                          MAX31827_CONFIGURATION_1SHOT_MASK,
 238                                                          1);
 239                                 if (ret) {
 240                                         mutex_unlock(&st->lock);
 241                                         return ret;
 242                                 }
 243                                 msleep(max31827_conv_times[st->resolution]);
 244                         }
 245
 246                         /*
 247                          * For 12-bit resolution the conversion time is 140 ms,
 248                          * thus an additional 15 ms is needed to complete the
 249                          * conversion: 125 ms + 15 ms = 140 ms
 250                          */
 251                         if (max31827_resolutions[st->resolution] == 12 &&
 252                             st->update_interval == 125)
 253                                 usleep_range(15000, 20000);
 254
 255                         ret = regmap_read(st->regmap, MAX31827_T_REG, &uval);
 256
 257                         mutex_unlock(&st->lock);
 258
 259                         if (ret)
 260                                 break;
 261
 262                         *val = MAX31827_16_BIT_TO_M_DGR(uval);
 263
 264                         break;
 265                 case hwmon_temp_max:
 266                         ret = regmap_read(st->regmap, MAX31827_TH_REG, &uval);
 267                         if (ret)
 268                                 break;
 269
 270                         *val = MAX31827_16_BIT_TO_M_DGR(uval);
 271                         break;
 272                 case hwmon_temp_max_hyst:
 273                         ret = regmap_read(st->regmap, MAX31827_TH_HYST_REG,
 274                                           &uval);
 275                         if (ret)
 276                                 break;
 277
 278                         *val = MAX31827_16_BIT_TO_M_DGR(uval);
 279                         break;
 280                 case hwmon_temp_max_alarm:
 281                         ret = regmap_read(st->regmap,
 282                                           MAX31827_CONFIGURATION_REG, &uval);
 283                         if (ret)
 284                                 break;
 285
 286                         *val = FIELD_GET(MAX31827_CONFIGURATION_O_TEMP_STAT_MASK,
 287                                          uval);
 288                         break;
 289                 case hwmon_temp_min:
 290                         ret = regmap_read(st->regmap, MAX31827_TL_REG, &uval);
 291                         if (ret)
 292                                 break;
 293
 294                         *val = MAX31827_16_BIT_TO_M_DGR(uval);
 295                         break;
 296                 case hwmon_temp_min_hyst:
 297                         ret = regmap_read(st->regmap, MAX31827_TL_HYST_REG,
 298                                           &uval);
 299                         if (ret)
 300                                 break;
 301
 302                         *val = MAX31827_16_BIT_TO_M_DGR(uval);
 303                         break;
 304                 case hwmon_temp_min_alarm:
 305                         ret = regmap_read(st->regmap,
 306                                           MAX31827_CONFIGURATION_REG, &uval);
 307                         if (ret)
 308                                 break;
 309
 310                         *val = FIELD_GET(MAX31827_CONFIGURATION_U_TEMP_STAT_MASK,
 311                                          uval);
 312                         break;
 313                 default:
 314                         ret = -EOPNOTSUPP;
 315                         break;
 316                 }
 317
 318                 break;
 319
 320         case hwmon_chip:
 321                 if (attr == hwmon_chip_update_interval) {
 322                         ret = regmap_read(st->regmap,
 323                                           MAX31827_CONFIGURATION_REG, &uval);
 324                         if (ret)
 325                                 break;
 326
 327                         uval = FIELD_GET(MAX31827_CONFIGURATION_CNV_RATE_MASK,
 328                                          uval);
 329                         *val = max31827_conversions[uval];
 330                 }
 331                 break;
 332
 333         default:
 334                 ret = -EOPNOTSUPP;
 335                 break;
 336         }
 337
 338         return ret;
 339 }
 340
 341 static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
 342                           u32 attr, int channel, long val)
 343 {
 344         struct max31827_state *st = dev_get_drvdata(dev);
 345         int res = 1;
 346         int ret;
 347
 348         switch (type) {
 349         case hwmon_temp:
 350                 switch (attr) {
 351                 case hwmon_temp_enable:
 352                         if (val >> 1)
 353                                 return -EINVAL;
 354
 355                         mutex_lock(&st->lock);
 356                         /**
 357                          * The chip should not be enabled while a conversion is
 358                          * performed. Neither should the chip be enabled when
 359                          * the alarm values are changed.
 360                          */
 361
 362                         st->enable = val;
 363
 364                         ret = regmap_update_bits(st->regmap,
 365                                                  MAX31827_CONFIGURATION_REG,
 366                                                  MAX31827_CONFIGURATION_1SHOT_MASK |
 367                                                  MAX31827_CONFIGURATION_CNV_RATE_MASK,
 368                                                  MAX31827_DEVICE_ENABLE(val));
 369
 370                         mutex_unlock(&st->lock);
 371
 372                         return ret;
 373
 374                 case hwmon_temp_max:
 375                         return write_alarm_val(st, MAX31827_TH_REG, val);
 376
 377                 case hwmon_temp_max_hyst:
 378                         return write_alarm_val(st, MAX31827_TH_HYST_REG, val);
 379
 380                 case hwmon_temp_min:
 381                         return write_alarm_val(st, MAX31827_TL_REG, val);
 382
 383                 case hwmon_temp_min_hyst:
 384                         return write_alarm_val(st, MAX31827_TL_HYST_REG, val);
 385
 386                 default:
 387                         return -EOPNOTSUPP;
 388                 }
 389
 390         case hwmon_chip:
 391                 switch (attr) {
 392                 case hwmon_chip_update_interval:
 393                         if (!st->enable)
 394                                 return -EINVAL;
 395
 396                         /*
 397                          * Convert the desired conversion rate into register
 398                          * bits. res is already initialized with 1.
 399                          *
 400                          * This was inspired by lm73 driver.
 401                          */
 402                         while (res < ARRAY_SIZE(max31827_conversions) &&
 403                                val < max31827_conversions[res])
 404                                 res++;
 405
 406                         if (res == ARRAY_SIZE(max31827_conversions))
 407                                 res = ARRAY_SIZE(max31827_conversions) - 1;
 408
 409                         res = FIELD_PREP(MAX31827_CONFIGURATION_CNV_RATE_MASK,
 410                                          res);
 411
 412                         ret = regmap_update_bits(st->regmap,
 413                                                  MAX31827_CONFIGURATION_REG,
 414                                                  MAX31827_CONFIGURATION_CNV_RATE_MASK,
 415                                                  res);
 416                         if (ret)
 417                                 return ret;
 418
 419                         st->update_interval = val;
 420
 421                         return 0;
 422                 case hwmon_chip_pec:
 423                         return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
 424                                                   MAX31827_CONFIGURATION_PEC_EN_MASK,
 425                                                   val ? MAX31827_CONFIGURATION_PEC_EN_MASK : 0);
 426                 default:
 427                         return -EOPNOTSUPP;
 428                 }
 429         default:
 430                 return -EOPNOTSUPP;
 431         }
 432 }
 433
 434 static ssize_t temp1_resolution_show(struct device *dev,
 435                                      struct device_attribute *devattr,
 436                                      char *buf)
 437 {
 438         struct max31827_state *st = dev_get_drvdata(dev);
 439         unsigned int val;
 440         int ret;
 441
 442         ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &val);
 443         if (ret)
 444                 return ret;
 445
 446         val = FIELD_GET(MAX31827_CONFIGURATION_RESOLUTION_MASK, val);
 447
 448         return scnprintf(buf, PAGE_SIZE, "%u\n", max31827_resolutions[val]);
 449 }
 450
 451 static ssize_t temp1_resolution_store(struct device *dev,
 452                                       struct device_attribute *devattr,
 453                                       const char *buf, size_t count)
 454 {
 455         struct max31827_state *st = dev_get_drvdata(dev);
 456         unsigned int idx = 0;
 457         unsigned int val;
 458         int ret;
 459
 460         ret = kstrtouint(buf, 10, &val);
 461         if (ret)
 462                 return ret;
 463
 464         /*
 465          * Convert the desired resolution into register
 466          * bits. idx is already initialized with 0.
 467          *
 468          * This was inspired by lm73 driver.
 469          */
 470         while (idx < ARRAY_SIZE(max31827_resolutions) &&
 471                val < max31827_resolutions[idx])
 472                 idx++;
 473
 474         if (idx == ARRAY_SIZE(max31827_resolutions))
 475                 idx = ARRAY_SIZE(max31827_resolutions) - 1;
 476
 477         st->resolution = idx;
 478
 479         ret = shutdown_write(st, MAX31827_CONFIGURATION_REG,
 480                              MAX31827_CONFIGURATION_RESOLUTION_MASK,
 481                              FIELD_PREP(MAX31827_CONFIGURATION_RESOLUTION_MASK,
 482                                         idx));
 483
 484         return ret ? ret : count;
 485 }
 486
 487 static DEVICE_ATTR_RW(temp1_resolution);
 488
 489 static struct attribute *max31827_attrs[] = {
 490         &dev_attr_temp1_resolution.attr,
 491         NULL
 492 };
 493 ATTRIBUTE_GROUPS(max31827);
 494
 495 static const struct i2c_device_id max31827_i2c_ids[] = {
 496         { "max31827", max31827 },
 497         { "max31828", max31828 },
 498         { "max31829", max31829 },
 499         { }
 500 };
 501 MODULE_DEVICE_TABLE(i2c, max31827_i2c_ids);
 502
 503 static int max31827_init_client(struct max31827_state *st,
 504                                 struct device *dev)
 505 {
 506         struct fwnode_handle *fwnode;
 507         unsigned int res = 0;
 508         u32 data, lsb_idx;
 509         enum chips type;
 510         bool prop;
 511         int ret;
 512
 513         fwnode = dev_fwnode(dev);
 514
 515         st->enable = true;
 516         res |= MAX31827_DEVICE_ENABLE(1);
 517
 518         res |= MAX31827_CONFIGURATION_RESOLUTION_MASK;
 519
 520         prop = fwnode_property_read_bool(fwnode, "adi,comp-int");
 521         res |= FIELD_PREP(MAX31827_CONFIGURATION_COMP_INT_MASK, prop);
 522
 523         prop = fwnode_property_read_bool(fwnode, "adi,timeout-enable");
 524         res |= FIELD_PREP(MAX31827_CONFIGURATION_TIMEOUT_MASK, !prop);
 525
 526         type = (enum chips)(uintptr_t)device_get_match_data(dev);
 527
 528         if (fwnode_property_present(fwnode, "adi,alarm-pol")) {
 529                 ret = fwnode_property_read_u32(fwnode, "adi,alarm-pol", &data);
 530                 if (ret)
 531                         return ret;
 532
 533                 res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK, !!data);
 534         } else {
 535                 /*
 536                  * Set default value.
 537                  */
 538                 switch (type) {
 539                 case max31827:
 540                 case max31828:
 541                         res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK,
 542                                           MAX31827_ALRM_POL_LOW);
 543                         break;
 544                 case max31829:
 545                         res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK,
 546                                           MAX31827_ALRM_POL_HIGH);
 547                         break;
 548                 default:
 549                         return -EOPNOTSUPP;
 550                 }
 551         }
 552
 553         if (fwnode_property_present(fwnode, "adi,fault-q")) {
 554                 ret = fwnode_property_read_u32(fwnode, "adi,fault-q", &data);
 555                 if (ret)
 556                         return ret;
 557
 558                 /*
 559                  * Convert the desired fault queue into register bits.
 560                  */
 561                 if (data != 0)
 562                         lsb_idx = __ffs(data);
 563
 564                 if (hweight32(data) != 1 || lsb_idx > 4) {
 565                         dev_err(dev, "Invalid data in adi,fault-q\n");
 566                         return -EINVAL;
 567                 }
 568
 569                 res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK, lsb_idx);
 570         } else {
 571                 /*
 572                  * Set default value.
 573                  */
 574                 switch (type) {
 575                 case max31827:
 576                         res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK,
 577                                           MAX31827_FLT_Q_1);
 578                         break;
 579                 case max31828:
 580                 case max31829:
 581                         res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK,
 582                                           MAX31827_FLT_Q_4);
 583                         break;
 584                 default:
 585                         return -EOPNOTSUPP;
 586                 }
 587         }
 588
 589         return regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, res);
 590 }
 591
 592 static const struct hwmon_channel_info *max31827_info[] = {
 593         HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT | HWMON_T_MIN |
 594                                          HWMON_T_MIN_HYST | HWMON_T_MIN_ALARM |
 595                                          HWMON_T_MAX | HWMON_T_MAX_HYST |
 596                                          HWMON_T_MAX_ALARM),
 597         HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL | HWMON_C_PEC),
 598         NULL,
 599 };
 600
 601 static const struct hwmon_ops max31827_hwmon_ops = {
 602         .is_visible = max31827_is_visible,
 603         .read = max31827_read,
 604         .write = max31827_write,
 605 };
 606
 607 static const struct hwmon_chip_info max31827_chip_info = {
 608         .ops = &max31827_hwmon_ops,
 609         .info = max31827_info,
 610 };
 611
 612 static int max31827_probe(struct i2c_client *client)
 613 {
 614         struct device *dev = &client->dev;
 615         struct device *hwmon_dev;
 616         struct max31827_state *st;
 617         int err;
 618
 619         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 620                 return -EOPNOTSUPP;
 621
 622         st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
 623         if (!st)
 624                 return -ENOMEM;
 625
 626         mutex_init(&st->lock);
 627
 628         st->regmap = devm_regmap_init_i2c(client, &max31827_regmap);
 629         if (IS_ERR(st->regmap))
 630                 return dev_err_probe(dev, PTR_ERR(st->regmap),
 631                                      "Failed to allocate regmap.\n");
 632
 633         err = devm_regulator_get_enable(dev, "vref");
 634         if (err)
 635                 return dev_err_probe(dev, err, "failed to enable regulator\n");
 636
 637         err = max31827_init_client(st, dev);
 638         if (err)
 639                 return err;
 640
 641         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, st,
 642                                                          &max31827_chip_info,
 643                                                          max31827_groups);
 644
 645         return PTR_ERR_OR_ZERO(hwmon_dev);
 646 }
 647
 648 static const struct of_device_id max31827_of_match[] = {
 649         {
 650                 .compatible = "adi,max31827",
 651                 .data = (void *)max31827
 652         },
 653         {
 654                 .compatible = "adi,max31828",
 655                 .data = (void *)max31828
 656         },
 657         {
 658                 .compatible = "adi,max31829",
 659                 .data = (void *)max31829
 660         },
 661         { }
 662 };
 663 MODULE_DEVICE_TABLE(of, max31827_of_match);
 664
 665 static struct i2c_driver max31827_driver = {
 666         .driver = {
 667                 .name = "max31827",
 668                 .of_match_table = max31827_of_match,
 669         },
 670         .probe = max31827_probe,
 671         .id_table = max31827_i2c_ids,
 672 };
 673 module_i2c_driver(max31827_driver);
 674
 675 MODULE_AUTHOR("Daniel Matyas <daniel.matyas@analog.com>");
 676 MODULE_DESCRIPTION("Maxim MAX31827 low-power temperature switch driver");
 677 MODULE_LICENSE("GPL");