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