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