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