drivers/hwmon/lm75.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * lm75.c - Part of lm_sensors, Linux kernel modules for hardware
   4  *       monitoring
   5  * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/jiffies.h>
  12 #include <linux/i2c.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/hwmon-sysfs.h>
  15 #include <linux/err.h>
  16 #include <linux/of_device.h>
  17 #include <linux/of.h>
  18 #include <linux/regmap.h>
  19 #include <linux/util_macros.h>
  20 #include <linux/regulator/consumer.h>
  21 #include "lm75.h"
  22
  23 /*
  24  * This driver handles the LM75 and compatible digital temperature sensors.
  25  */
  26
  27 enum lm75_type {                /* keep sorted in alphabetical order */
  28         adt75,
  29         at30ts74,
  30         ds1775,
  31         ds75,
  32         ds7505,
  33         g751,
  34         lm75,
  35         lm75a,
  36         lm75b,
  37         max6625,
  38         max6626,
  39         max31725,
  40         mcp980x,
  41         pct2075,
  42         stds75,
  43         stlm75,
  44         tcn75,
  45         tmp100,
  46         tmp101,
  47         tmp105,
  48         tmp112,
  49         tmp175,
  50         tmp275,
  51         tmp75,
  52         tmp75b,
  53         tmp75c,
  54         tmp1075,
  55 };
  56
  57 /**
  58  * struct lm75_params - lm75 configuration parameters.
  59  * @set_mask:           Bits to set in configuration register when configuring
  60  *                      the chip.
  61  * @clr_mask:           Bits to clear in configuration register when configuring
  62  *                      the chip.
  63  * @default_resolution: Default number of bits to represent the temperature
  64  *                      value.
  65  * @resolution_limits:  Limit register resolution. Optional. Should be set if
  66  *                      the resolution of limit registers does not match the
  67  *                      resolution of the temperature register.
  68  * @resolutions:        List of resolutions associated with sample times.
  69  *                      Optional. Should be set if num_sample_times is larger
  70  *                      than 1, and if the resolution changes with sample times.
  71  *                      If set, number of entries must match num_sample_times.
  72  * @default_sample_time:Sample time to be set by default.
  73  * @num_sample_times:   Number of possible sample times to be set. Optional.
  74  *                      Should be set if the number of sample times is larger
  75  *                      than one.
  76  * @sample_times:       All the possible sample times to be set. Mandatory if
  77  *                      num_sample_times is larger than 1. If set, number of
  78  *                      entries must match num_sample_times.
  79  */
  80
  81 struct lm75_params {
  82         u8                      set_mask;
  83         u8                      clr_mask;
  84         u8                      default_resolution;
  85         u8                      resolution_limits;
  86         const u8                *resolutions;
  87         unsigned int            default_sample_time;
  88         u8                      num_sample_times;
  89         const unsigned int      *sample_times;
  90 };
  91
  92 /* Addresses scanned */
  93 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
  94                                         0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
  95
  96 /* The LM75 registers */
  97 #define LM75_REG_TEMP           0x00
  98 #define LM75_REG_CONF           0x01
  99 #define LM75_REG_HYST           0x02
 100 #define LM75_REG_MAX            0x03
 101 #define PCT2075_REG_IDLE        0x04
 102
 103 /* Each client has this additional data */
 104 struct lm75_data {
 105         struct i2c_client               *client;
 106         struct regmap                   *regmap;
 107         struct regulator                *vs;
 108         u8                              orig_conf;
 109         u8                              current_conf;
 110         u8                              resolution;     /* In bits, 9 to 16 */
 111         unsigned int                    sample_time;    /* In ms */
 112         enum lm75_type                  kind;
 113         const struct lm75_params        *params;
 114 };
 115
 116 /*-----------------------------------------------------------------------*/
 117
 118 static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };
 119
 120 #define LM75_SAMPLE_CLEAR_MASK  (3 << 5)
 121
 122 /* The structure below stores the configuration values of the supported devices.
 123  * In case of being supported multiple configurations, the default one must
 124  * always be the first element of the array
 125  */
 126 static const struct lm75_params device_params[] = {
 127         [adt75] = {
 128                 .clr_mask = 1 << 5,     /* not one-shot mode */
 129                 .default_resolution = 12,
 130                 .default_sample_time = MSEC_PER_SEC / 10,
 131         },
 132         [at30ts74] = {
 133                 .set_mask = 3 << 5,     /* 12-bit mode*/
 134                 .default_resolution = 12,
 135                 .default_sample_time = 200,
 136                 .num_sample_times = 4,
 137                 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
 138                 .resolutions = (u8 []) {9, 10, 11, 12 },
 139         },
 140         [ds1775] = {
 141                 .clr_mask = 3 << 5,
 142                 .set_mask = 2 << 5,     /* 11-bit mode */
 143                 .default_resolution = 11,
 144                 .default_sample_time = 500,
 145                 .num_sample_times = 4,
 146                 .sample_times = (unsigned int []){ 125, 250, 500, 1000 },
 147                 .resolutions = (u8 []) {9, 10, 11, 12 },
 148         },
 149         [ds75] = {
 150                 .clr_mask = 3 << 5,
 151                 .set_mask = 2 << 5,     /* 11-bit mode */
 152                 .default_resolution = 11,
 153                 .default_sample_time = 600,
 154                 .num_sample_times = 4,
 155                 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
 156                 .resolutions = (u8 []) {9, 10, 11, 12 },
 157         },
 158         [stds75] = {
 159                 .clr_mask = 3 << 5,
 160                 .set_mask = 2 << 5,     /* 11-bit mode */
 161                 .default_resolution = 11,
 162                 .default_sample_time = 600,
 163                 .num_sample_times = 4,
 164                 .sample_times = (unsigned int []){ 150, 300, 600, 1200 },
 165                 .resolutions = (u8 []) {9, 10, 11, 12 },
 166         },
 167         [stlm75] = {
 168                 .default_resolution = 9,
 169                 .default_sample_time = MSEC_PER_SEC / 6,
 170         },
 171         [ds7505] = {
 172                 .set_mask = 3 << 5,     /* 12-bit mode*/
 173                 .default_resolution = 12,
 174                 .default_sample_time = 200,
 175                 .num_sample_times = 4,
 176                 .sample_times = (unsigned int []){ 25, 50, 100, 200 },
 177                 .resolutions = (u8 []) {9, 10, 11, 12 },
 178         },
 179         [g751] = {
 180                 .default_resolution = 9,
 181                 .default_sample_time = MSEC_PER_SEC / 10,
 182         },
 183         [lm75] = {
 184                 .default_resolution = 9,
 185                 .default_sample_time = MSEC_PER_SEC / 10,
 186         },
 187         [lm75a] = {
 188                 .default_resolution = 9,
 189                 .default_sample_time = MSEC_PER_SEC / 10,
 190         },
 191         [lm75b] = {
 192                 .default_resolution = 11,
 193                 .default_sample_time = MSEC_PER_SEC / 10,
 194         },
 195         [max6625] = {
 196                 .default_resolution = 9,
 197                 .default_sample_time = MSEC_PER_SEC / 7,
 198         },
 199         [max6626] = {
 200                 .default_resolution = 12,
 201                 .default_sample_time = MSEC_PER_SEC / 7,
 202                 .resolution_limits = 9,
 203         },
 204         [max31725] = {
 205                 .default_resolution = 16,
 206                 .default_sample_time = MSEC_PER_SEC / 20,
 207         },
 208         [tcn75] = {
 209                 .default_resolution = 9,
 210                 .default_sample_time = MSEC_PER_SEC / 18,
 211         },
 212         [pct2075] = {
 213                 .default_resolution = 11,
 214                 .default_sample_time = MSEC_PER_SEC / 10,
 215                 .num_sample_times = 31,
 216                 .sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600,
 217                 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700,
 218                 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700,
 219                 2800, 2900, 3000, 3100 },
 220         },
 221         [mcp980x] = {
 222                 .set_mask = 3 << 5,     /* 12-bit mode */
 223                 .clr_mask = 1 << 7,     /* not one-shot mode */
 224                 .default_resolution = 12,
 225                 .resolution_limits = 9,
 226                 .default_sample_time = 240,
 227                 .num_sample_times = 4,
 228                 .sample_times = (unsigned int []){ 30, 60, 120, 240 },
 229                 .resolutions = (u8 []) {9, 10, 11, 12 },
 230         },
 231         [tmp100] = {
 232                 .set_mask = 3 << 5,     /* 12-bit mode */
 233                 .clr_mask = 1 << 7,     /* not one-shot mode */
 234                 .default_resolution = 12,
 235                 .default_sample_time = 320,
 236                 .num_sample_times = 4,
 237                 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
 238                 .resolutions = (u8 []) {9, 10, 11, 12 },
 239         },
 240         [tmp101] = {
 241                 .set_mask = 3 << 5,     /* 12-bit mode */
 242                 .clr_mask = 1 << 7,     /* not one-shot mode */
 243                 .default_resolution = 12,
 244                 .default_sample_time = 320,
 245                 .num_sample_times = 4,
 246                 .sample_times = (unsigned int []){ 40, 80, 160, 320 },
 247                 .resolutions = (u8 []) {9, 10, 11, 12 },
 248         },
 249         [tmp105] = {
 250                 .set_mask = 3 << 5,     /* 12-bit mode */
 251                 .clr_mask = 1 << 7,     /* not one-shot mode*/
 252                 .default_resolution = 12,
 253                 .default_sample_time = 220,
 254                 .num_sample_times = 4,
 255                 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
 256                 .resolutions = (u8 []) {9, 10, 11, 12 },
 257         },
 258         [tmp112] = {
 259                 .set_mask = 3 << 5,     /* 8 samples / second */
 260                 .clr_mask = 1 << 7,     /* no one-shot mode*/
 261                 .default_resolution = 12,
 262                 .default_sample_time = 125,
 263                 .num_sample_times = 4,
 264                 .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
 265         },
 266         [tmp175] = {
 267                 .set_mask = 3 << 5,     /* 12-bit mode */
 268                 .clr_mask = 1 << 7,     /* not one-shot mode*/
 269                 .default_resolution = 12,
 270                 .default_sample_time = 220,
 271                 .num_sample_times = 4,
 272                 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
 273                 .resolutions = (u8 []) {9, 10, 11, 12 },
 274         },
 275         [tmp275] = {
 276                 .set_mask = 3 << 5,     /* 12-bit mode */
 277                 .clr_mask = 1 << 7,     /* not one-shot mode*/
 278                 .default_resolution = 12,
 279                 .default_sample_time = 220,
 280                 .num_sample_times = 4,
 281                 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
 282                 .resolutions = (u8 []) {9, 10, 11, 12 },
 283         },
 284         [tmp75] = {
 285                 .set_mask = 3 << 5,     /* 12-bit mode */
 286                 .clr_mask = 1 << 7,     /* not one-shot mode*/
 287                 .default_resolution = 12,
 288                 .default_sample_time = 220,
 289                 .num_sample_times = 4,
 290                 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
 291                 .resolutions = (u8 []) {9, 10, 11, 12 },
 292         },
 293         [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */
 294                 .clr_mask = 1 << 7 | 3 << 5,
 295                 .default_resolution = 12,
 296                 .default_sample_time = MSEC_PER_SEC / 37,
 297                 .sample_times = (unsigned int []){ MSEC_PER_SEC / 37,
 298                         MSEC_PER_SEC / 18,
 299                         MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 },
 300                 .num_sample_times = 4,
 301         },
 302         [tmp75c] = {
 303                 .clr_mask = 1 << 5,     /*not one-shot mode*/
 304                 .default_resolution = 12,
 305                 .default_sample_time = MSEC_PER_SEC / 12,
 306         },
 307         [tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */
 308                 .clr_mask = 1 << 5 | 1 << 6 | 1 << 7,
 309                 .default_resolution = 12,
 310                 .default_sample_time = 28,
 311                 .num_sample_times = 4,
 312                 .sample_times = (unsigned int []){ 28, 55, 110, 220 },
 313         }
 314 };
 315
 316 static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
 317 {
 318         return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
 319 }
 320
 321 static int lm75_write_config(struct lm75_data *data, u8 set_mask,
 322                              u8 clr_mask)
 323 {
 324         u8 value;
 325
 326         clr_mask |= LM75_SHUTDOWN;
 327         value = data->current_conf & ~clr_mask;
 328         value |= set_mask;
 329
 330         if (data->current_conf != value) {
 331                 s32 err;
 332
 333                 err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF,
 334                                                 value);
 335                 if (err)
 336                         return err;
 337                 data->current_conf = value;
 338         }
 339         return 0;
 340 }
 341
 342 static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
 343                      u32 attr, int channel, long *val)
 344 {
 345         struct lm75_data *data = dev_get_drvdata(dev);
 346         unsigned int regval;
 347         int err, reg;
 348
 349         switch (type) {
 350         case hwmon_chip:
 351                 switch (attr) {
 352                 case hwmon_chip_update_interval:
 353                         *val = data->sample_time;
 354                         break;
 355                 default:
 356                         return -EINVAL;
 357                 }
 358                 break;
 359         case hwmon_temp:
 360                 switch (attr) {
 361                 case hwmon_temp_input:
 362                         reg = LM75_REG_TEMP;
 363                         break;
 364                 case hwmon_temp_max:
 365                         reg = LM75_REG_MAX;
 366                         break;
 367                 case hwmon_temp_max_hyst:
 368                         reg = LM75_REG_HYST;
 369                         break;
 370                 default:
 371                         return -EINVAL;
 372                 }
 373                 err = regmap_read(data->regmap, reg, &regval);
 374                 if (err < 0)
 375                         return err;
 376
 377                 *val = lm75_reg_to_mc(regval, data->resolution);
 378                 break;
 379         default:
 380                 return -EINVAL;
 381         }
 382         return 0;
 383 }
 384
 385 static int lm75_write_temp(struct device *dev, u32 attr, long temp)
 386 {
 387         struct lm75_data *data = dev_get_drvdata(dev);
 388         u8 resolution;
 389         int reg;
 390
 391         switch (attr) {
 392         case hwmon_temp_max:
 393                 reg = LM75_REG_MAX;
 394                 break;
 395         case hwmon_temp_max_hyst:
 396                 reg = LM75_REG_HYST;
 397                 break;
 398         default:
 399                 return -EINVAL;
 400         }
 401
 402         /*
 403          * Resolution of limit registers is assumed to be the same as the
 404          * temperature input register resolution unless given explicitly.
 405          */
 406         if (data->params->resolution_limits)
 407                 resolution = data->params->resolution_limits;
 408         else
 409                 resolution = data->resolution;
 410
 411         temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
 412         temp = DIV_ROUND_CLOSEST(temp  << (resolution - 8),
 413                                  1000) << (16 - resolution);
 414
 415         return regmap_write(data->regmap, reg, (u16)temp);
 416 }
 417
 418 static int lm75_update_interval(struct device *dev, long val)
 419 {
 420         struct lm75_data *data = dev_get_drvdata(dev);
 421         unsigned int reg;
 422         u8 index;
 423         s32 err;
 424
 425         index = find_closest(val, data->params->sample_times,
 426                              (int)data->params->num_sample_times);
 427
 428         switch (data->kind) {
 429         default:
 430                 err = lm75_write_config(data, lm75_sample_set_masks[index],
 431                                         LM75_SAMPLE_CLEAR_MASK);
 432                 if (err)
 433                         return err;
 434
 435                 data->sample_time = data->params->sample_times[index];
 436                 if (data->params->resolutions)
 437                         data->resolution = data->params->resolutions[index];
 438                 break;
 439         case tmp112:
 440                 err = regmap_read(data->regmap, LM75_REG_CONF, &reg);
 441                 if (err < 0)
 442                         return err;
 443                 reg &= ~0x00c0;
 444                 reg |= (3 - index) << 6;
 445                 err = regmap_write(data->regmap, LM75_REG_CONF, reg);
 446                 if (err < 0)
 447                         return err;
 448                 data->sample_time = data->params->sample_times[index];
 449                 break;
 450         case pct2075:
 451                 err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE,
 452                                                 index + 1);
 453                 if (err)
 454                         return err;
 455                 data->sample_time = data->params->sample_times[index];
 456                 break;
 457         }
 458         return 0;
 459 }
 460
 461 static int lm75_write_chip(struct device *dev, u32 attr, long val)
 462 {
 463         switch (attr) {
 464         case hwmon_chip_update_interval:
 465                 return lm75_update_interval(dev, val);
 466         default:
 467                 return -EINVAL;
 468         }
 469         return 0;
 470 }
 471
 472 static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
 473                       u32 attr, int channel, long val)
 474 {
 475         switch (type) {
 476         case hwmon_chip:
 477                 return lm75_write_chip(dev, attr, val);
 478         case hwmon_temp:
 479                 return lm75_write_temp(dev, attr, val);
 480         default:
 481                 return -EINVAL;
 482         }
 483         return 0;
 484 }
 485
 486 static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
 487                                u32 attr, int channel)
 488 {
 489         const struct lm75_data *config_data = data;
 490
 491         switch (type) {
 492         case hwmon_chip:
 493                 switch (attr) {
 494                 case hwmon_chip_update_interval:
 495                         if (config_data->params->num_sample_times > 1)
 496                                 return 0644;
 497                         return 0444;
 498                 }
 499                 break;
 500         case hwmon_temp:
 501                 switch (attr) {
 502                 case hwmon_temp_input:
 503                         return 0444;
 504                 case hwmon_temp_max:
 505                 case hwmon_temp_max_hyst:
 506                         return 0644;
 507                 }
 508                 break;
 509         default:
 510                 break;
 511         }
 512         return 0;
 513 }
 514
 515 static const struct hwmon_channel_info * const lm75_info[] = {
 516         HWMON_CHANNEL_INFO(chip,
 517                            HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
 518         HWMON_CHANNEL_INFO(temp,
 519                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
 520         NULL
 521 };
 522
 523 static const struct hwmon_ops lm75_hwmon_ops = {
 524         .is_visible = lm75_is_visible,
 525         .read = lm75_read,
 526         .write = lm75_write,
 527 };
 528
 529 static const struct hwmon_chip_info lm75_chip_info = {
 530         .ops = &lm75_hwmon_ops,
 531         .info = lm75_info,
 532 };
 533
 534 static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
 535 {
 536         return reg != LM75_REG_TEMP;
 537 }
 538
 539 static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
 540 {
 541         return reg == LM75_REG_TEMP || reg == LM75_REG_CONF;
 542 }
 543
 544 static const struct regmap_config lm75_regmap_config = {
 545         .reg_bits = 8,
 546         .val_bits = 16,
 547         .max_register = PCT2075_REG_IDLE,
 548         .writeable_reg = lm75_is_writeable_reg,
 549         .volatile_reg = lm75_is_volatile_reg,
 550         .val_format_endian = REGMAP_ENDIAN_BIG,
 551         .cache_type = REGCACHE_MAPLE,
 552         .use_single_read = true,
 553         .use_single_write = true,
 554 };
 555
 556 static void lm75_disable_regulator(void *data)
 557 {
 558         struct lm75_data *lm75 = data;
 559
 560         regulator_disable(lm75->vs);
 561 }
 562
 563 static void lm75_remove(void *data)
 564 {
 565         struct lm75_data *lm75 = data;
 566         struct i2c_client *client = lm75->client;
 567
 568         i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
 569 }
 570
 571 static const struct i2c_device_id lm75_ids[];
 572
 573 static int lm75_probe(struct i2c_client *client)
 574 {
 575         struct device *dev = &client->dev;
 576         struct device *hwmon_dev;
 577         struct lm75_data *data;
 578         int status, err;
 579         enum lm75_type kind;
 580
 581         if (client->dev.of_node)
 582                 kind = (enum lm75_type)of_device_get_match_data(&client->dev);
 583         else
 584                 kind = i2c_match_id(lm75_ids, client)->driver_data;
 585
 586         if (!i2c_check_functionality(client->adapter,
 587                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 588                 return -EIO;
 589
 590         data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
 591         if (!data)
 592                 return -ENOMEM;
 593
 594         data->client = client;
 595         data->kind = kind;
 596
 597         data->vs = devm_regulator_get(dev, "vs");
 598         if (IS_ERR(data->vs))
 599                 return PTR_ERR(data->vs);
 600
 601         data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
 602         if (IS_ERR(data->regmap))
 603                 return PTR_ERR(data->regmap);
 604
 605         /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
 606          * Then tweak to be more precise when appropriate.
 607          */
 608
 609         data->params = &device_params[data->kind];
 610
 611         /* Save default sample time and resolution*/
 612         data->sample_time = data->params->default_sample_time;
 613         data->resolution = data->params->default_resolution;
 614
 615         /* Enable the power */
 616         err = regulator_enable(data->vs);
 617         if (err) {
 618                 dev_err(dev, "failed to enable regulator: %d\n", err);
 619                 return err;
 620         }
 621
 622         err = devm_add_action_or_reset(dev, lm75_disable_regulator, data);
 623         if (err)
 624                 return err;
 625
 626         /* Cache original configuration */
 627         status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
 628         if (status < 0) {
 629                 dev_dbg(dev, "Can't read config? %d\n", status);
 630                 return status;
 631         }
 632         data->orig_conf = status;
 633         data->current_conf = status;
 634
 635         err = lm75_write_config(data, data->params->set_mask,
 636                                 data->params->clr_mask);
 637         if (err)
 638                 return err;
 639
 640         err = devm_add_action_or_reset(dev, lm75_remove, data);
 641         if (err)
 642                 return err;
 643
 644         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 645                                                          data, &lm75_chip_info,
 646                                                          NULL);
 647         if (IS_ERR(hwmon_dev))
 648                 return PTR_ERR(hwmon_dev);
 649
 650         dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
 651
 652         return 0;
 653 }
 654
 655 static const struct i2c_device_id lm75_ids[] = {
 656         { "adt75", adt75, },
 657         { "at30ts74", at30ts74, },
 658         { "ds1775", ds1775, },
 659         { "ds75", ds75, },
 660         { "ds7505", ds7505, },
 661         { "g751", g751, },
 662         { "lm75", lm75, },
 663         { "lm75a", lm75a, },
 664         { "lm75b", lm75b, },
 665         { "max6625", max6625, },
 666         { "max6626", max6626, },
 667         { "max31725", max31725, },
 668         { "max31726", max31725, },
 669         { "mcp980x", mcp980x, },
 670         { "pct2075", pct2075, },
 671         { "stds75", stds75, },
 672         { "stlm75", stlm75, },
 673         { "tcn75", tcn75, },
 674         { "tmp100", tmp100, },
 675         { "tmp101", tmp101, },
 676         { "tmp105", tmp105, },
 677         { "tmp112", tmp112, },
 678         { "tmp175", tmp175, },
 679         { "tmp275", tmp275, },
 680         { "tmp75", tmp75, },
 681         { "tmp75b", tmp75b, },
 682         { "tmp75c", tmp75c, },
 683         { "tmp1075", tmp1075, },
 684         { /* LIST END */ }
 685 };
 686 MODULE_DEVICE_TABLE(i2c, lm75_ids);
 687
 688 static const struct of_device_id __maybe_unused lm75_of_match[] = {
 689         {
 690                 .compatible = "adi,adt75",
 691                 .data = (void *)adt75
 692         },
 693         {
 694                 .compatible = "atmel,at30ts74",
 695                 .data = (void *)at30ts74
 696         },
 697         {
 698                 .compatible = "dallas,ds1775",
 699                 .data = (void *)ds1775
 700         },
 701         {
 702                 .compatible = "dallas,ds75",
 703                 .data = (void *)ds75
 704         },
 705         {
 706                 .compatible = "dallas,ds7505",
 707                 .data = (void *)ds7505
 708         },
 709         {
 710                 .compatible = "gmt,g751",
 711                 .data = (void *)g751
 712         },
 713         {
 714                 .compatible = "national,lm75",
 715                 .data = (void *)lm75
 716         },
 717         {
 718                 .compatible = "national,lm75a",
 719                 .data = (void *)lm75a
 720         },
 721         {
 722                 .compatible = "national,lm75b",
 723                 .data = (void *)lm75b
 724         },
 725         {
 726                 .compatible = "maxim,max6625",
 727                 .data = (void *)max6625
 728         },
 729         {
 730                 .compatible = "maxim,max6626",
 731                 .data = (void *)max6626
 732         },
 733         {
 734                 .compatible = "maxim,max31725",
 735                 .data = (void *)max31725
 736         },
 737         {
 738                 .compatible = "maxim,max31726",
 739                 .data = (void *)max31725
 740         },
 741         {
 742                 .compatible = "maxim,mcp980x",
 743                 .data = (void *)mcp980x
 744         },
 745         {
 746                 .compatible = "nxp,pct2075",
 747                 .data = (void *)pct2075
 748         },
 749         {
 750                 .compatible = "st,stds75",
 751                 .data = (void *)stds75
 752         },
 753         {
 754                 .compatible = "st,stlm75",
 755                 .data = (void *)stlm75
 756         },
 757         {
 758                 .compatible = "microchip,tcn75",
 759                 .data = (void *)tcn75
 760         },
 761         {
 762                 .compatible = "ti,tmp100",
 763                 .data = (void *)tmp100
 764         },
 765         {
 766                 .compatible = "ti,tmp101",
 767                 .data = (void *)tmp101
 768         },
 769         {
 770                 .compatible = "ti,tmp105",
 771                 .data = (void *)tmp105
 772         },
 773         {
 774                 .compatible = "ti,tmp112",
 775                 .data = (void *)tmp112
 776         },
 777         {
 778                 .compatible = "ti,tmp175",
 779                 .data = (void *)tmp175
 780         },
 781         {
 782                 .compatible = "ti,tmp275",
 783                 .data = (void *)tmp275
 784         },
 785         {
 786                 .compatible = "ti,tmp75",
 787                 .data = (void *)tmp75
 788         },
 789         {
 790                 .compatible = "ti,tmp75b",
 791                 .data = (void *)tmp75b
 792         },
 793         {
 794                 .compatible = "ti,tmp75c",
 795                 .data = (void *)tmp75c
 796         },
 797         {
 798                 .compatible = "ti,tmp1075",
 799                 .data = (void *)tmp1075
 800         },
 801         { },
 802 };
 803 MODULE_DEVICE_TABLE(of, lm75_of_match);
 804
 805 #define LM75A_ID 0xA1
 806
 807 /* Return 0 if detection is successful, -ENODEV otherwise */
 808 static int lm75_detect(struct i2c_client *new_client,
 809                        struct i2c_board_info *info)
 810 {
 811         struct i2c_adapter *adapter = new_client->adapter;
 812         int i;
 813         int conf, hyst, os;
 814         bool is_lm75a = 0;
 815
 816         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 817                                      I2C_FUNC_SMBUS_WORD_DATA))
 818                 return -ENODEV;
 819
 820         /*
 821          * Now, we do the remaining detection. There is no identification-
 822          * dedicated register so we have to rely on several tricks:
 823          * unused bits, registers cycling over 8-address boundaries,
 824          * addresses 0x04-0x07 returning the last read value.
 825          * The cycling+unused addresses combination is not tested,
 826          * since it would significantly slow the detection down and would
 827          * hardly add any value.
 828          *
 829          * The National Semiconductor LM75A is different than earlier
 830          * LM75s.  It has an ID byte of 0xaX (where X is the chip
 831          * revision, with 1 being the only revision in existence) in
 832          * register 7, and unused registers return 0xff rather than the
 833          * last read value.
 834          *
 835          * Note that this function only detects the original National
 836          * Semiconductor LM75 and the LM75A. Clones from other vendors
 837          * aren't detected, on purpose, because they are typically never
 838          * found on PC hardware. They are found on embedded designs where
 839          * they can be instantiated explicitly so detection is not needed.
 840          * The absence of identification registers on all these clones
 841          * would make their exhaustive detection very difficult and weak,
 842          * and odds are that the driver would bind to unsupported devices.
 843          */
 844
 845         /* Unused bits */
 846         conf = i2c_smbus_read_byte_data(new_client, 1);
 847         if (conf & 0xe0)
 848                 return -ENODEV;
 849
 850         /* First check for LM75A */
 851         if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
 852                 /*
 853                  * LM75A returns 0xff on unused registers so
 854                  * just to be sure we check for that too.
 855                  */
 856                 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
 857                  || i2c_smbus_read_byte_data(new_client, 5) != 0xff
 858                  || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
 859                         return -ENODEV;
 860                 is_lm75a = 1;
 861                 hyst = i2c_smbus_read_byte_data(new_client, 2);
 862                 os = i2c_smbus_read_byte_data(new_client, 3);
 863         } else { /* Traditional style LM75 detection */
 864                 /* Unused addresses */
 865                 hyst = i2c_smbus_read_byte_data(new_client, 2);
 866                 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
 867                  || i2c_smbus_read_byte_data(new_client, 5) != hyst
 868                  || i2c_smbus_read_byte_data(new_client, 6) != hyst
 869                  || i2c_smbus_read_byte_data(new_client, 7) != hyst)
 870                         return -ENODEV;
 871                 os = i2c_smbus_read_byte_data(new_client, 3);
 872                 if (i2c_smbus_read_byte_data(new_client, 4) != os
 873                  || i2c_smbus_read_byte_data(new_client, 5) != os
 874                  || i2c_smbus_read_byte_data(new_client, 6) != os
 875                  || i2c_smbus_read_byte_data(new_client, 7) != os)
 876                         return -ENODEV;
 877         }
 878         /*
 879          * It is very unlikely that this is a LM75 if both
 880          * hysteresis and temperature limit registers are 0.
 881          */
 882         if (hyst == 0 && os == 0)
 883                 return -ENODEV;
 884
 885         /* Addresses cycling */
 886         for (i = 8; i <= 248; i += 40) {
 887                 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
 888                  || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
 889                  || i2c_smbus_read_byte_data(new_client, i + 3) != os)
 890                         return -ENODEV;
 891                 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
 892                                 != LM75A_ID)
 893                         return -ENODEV;
 894         }
 895
 896         strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
 897
 898         return 0;
 899 }
 900
 901 #ifdef CONFIG_PM
 902 static int lm75_suspend(struct device *dev)
 903 {
 904         int status;
 905         struct i2c_client *client = to_i2c_client(dev);
 906
 907         status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
 908         if (status < 0) {
 909                 dev_dbg(&client->dev, "Can't read config? %d\n", status);
 910                 return status;
 911         }
 912         status = status | LM75_SHUTDOWN;
 913         i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
 914         return 0;
 915 }
 916
 917 static int lm75_resume(struct device *dev)
 918 {
 919         int status;
 920         struct i2c_client *client = to_i2c_client(dev);
 921
 922         status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
 923         if (status < 0) {
 924                 dev_dbg(&client->dev, "Can't read config? %d\n", status);
 925                 return status;
 926         }
 927         status = status & ~LM75_SHUTDOWN;
 928         i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
 929         return 0;
 930 }
 931
 932 static const struct dev_pm_ops lm75_dev_pm_ops = {
 933         .suspend        = lm75_suspend,
 934         .resume         = lm75_resume,
 935 };
 936 #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
 937 #else
 938 #define LM75_DEV_PM_OPS NULL
 939 #endif /* CONFIG_PM */
 940
 941 static struct i2c_driver lm75_driver = {
 942         .class          = I2C_CLASS_HWMON,
 943         .driver = {
 944                 .name   = "lm75",
 945                 .of_match_table = of_match_ptr(lm75_of_match),
 946                 .pm     = LM75_DEV_PM_OPS,
 947         },
 948         .probe          = lm75_probe,
 949         .id_table       = lm75_ids,
 950         .detect         = lm75_detect,
 951         .address_list   = normal_i2c,
 952 };
 953
 954 module_i2c_driver(lm75_driver);
 955
 956 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
 957 MODULE_DESCRIPTION("LM75 driver");
 958 MODULE_LICENSE("GPL");