drivers/hwmon/lm95245.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
   4  *
   5  * The LM95245 is a sensor chip made by TI / National Semiconductor.
   6  * It reports up to two temperatures (its own plus an external one).
   7  *
   8  * This driver is based on lm95241.c
   9  */
  10
  11 #include <linux/err.h>
  12 #include <linux/init.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/i2c.h>
  15 #include <linux/module.h>
  16 #include <linux/mutex.h>
  17 #include <linux/regmap.h>
  18 #include <linux/slab.h>
  19
  20 static const unsigned short normal_i2c[] = {
  21         0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
  22
  23 /* LM95245 registers */
  24 /* general registers */
  25 #define LM95245_REG_RW_CONFIG1          0x03
  26 #define LM95245_REG_RW_CONVERS_RATE     0x04
  27 #define LM95245_REG_W_ONE_SHOT          0x0F
  28
  29 /* diode configuration */
  30 #define LM95245_REG_RW_CONFIG2          0xBF
  31 #define LM95245_REG_RW_REMOTE_OFFH      0x11
  32 #define LM95245_REG_RW_REMOTE_OFFL      0x12
  33
  34 /* status registers */
  35 #define LM95245_REG_R_STATUS1           0x02
  36 #define LM95245_REG_R_STATUS2           0x33
  37
  38 /* limit registers */
  39 #define LM95245_REG_RW_REMOTE_OS_LIMIT          0x07
  40 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT     0x20
  41 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT       0x19
  42 #define LM95245_REG_RW_COMMON_HYSTERESIS        0x21
  43
  44 /* temperature signed */
  45 #define LM95245_REG_R_LOCAL_TEMPH_S     0x00
  46 #define LM95245_REG_R_LOCAL_TEMPL_S     0x30
  47 #define LM95245_REG_R_REMOTE_TEMPH_S    0x01
  48 #define LM95245_REG_R_REMOTE_TEMPL_S    0x10
  49 /* temperature unsigned */
  50 #define LM95245_REG_R_REMOTE_TEMPH_U    0x31
  51 #define LM95245_REG_R_REMOTE_TEMPL_U    0x32
  52
  53 /* id registers */
  54 #define LM95245_REG_R_MAN_ID            0xFE
  55 #define LM95245_REG_R_CHIP_ID           0xFF
  56
  57 /* LM95245 specific bitfields */
  58 #define CFG_STOP                0x40
  59 #define CFG_REMOTE_TCRIT_MASK   0x10
  60 #define CFG_REMOTE_OS_MASK      0x08
  61 #define CFG_LOCAL_TCRIT_MASK    0x04
  62 #define CFG_LOCAL_OS_MASK       0x02
  63
  64 #define CFG2_OS_A0              0x40
  65 #define CFG2_DIODE_FAULT_OS     0x20
  66 #define CFG2_DIODE_FAULT_TCRIT  0x10
  67 #define CFG2_REMOTE_TT          0x08
  68 #define CFG2_REMOTE_FILTER_DIS  0x00
  69 #define CFG2_REMOTE_FILTER_EN   0x06
  70
  71 /* conversation rate in ms */
  72 #define RATE_CR0063     0x00
  73 #define RATE_CR0364     0x01
  74 #define RATE_CR1000     0x02
  75 #define RATE_CR2500     0x03
  76
  77 #define STATUS1_ROS             0x10
  78 #define STATUS1_DIODE_FAULT     0x04
  79 #define STATUS1_RTCRIT          0x02
  80 #define STATUS1_LOC             0x01
  81
  82 #define MANUFACTURER_ID         0x01
  83 #define LM95235_REVISION        0xB1
  84 #define LM95245_REVISION        0xB3
  85
  86 /* Client data (each client gets its own) */
  87 struct lm95245_data {
  88         struct regmap *regmap;
  89         struct mutex update_lock;
  90         int interval;   /* in msecs */
  91 };
  92
  93 /* Conversions */
  94 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
  95 {
  96         return val_h * 1000 + val_l * 1000 / 256;
  97 }
  98
  99 static int temp_from_reg_signed(u8 val_h, u8 val_l)
 100 {
 101         if (val_h & 0x80)
 102                 return (val_h - 0x100) * 1000;
 103         return temp_from_reg_unsigned(val_h, val_l);
 104 }
 105
 106 static int lm95245_read_conversion_rate(struct lm95245_data *data)
 107 {
 108         unsigned int rate;
 109         int ret;
 110
 111         ret = regmap_read(data->regmap, LM95245_REG_RW_CONVERS_RATE, &rate);
 112         if (ret < 0)
 113                 return ret;
 114
 115         switch (rate) {
 116         case RATE_CR0063:
 117                 data->interval = 63;
 118                 break;
 119         case RATE_CR0364:
 120                 data->interval = 364;
 121                 break;
 122         case RATE_CR1000:
 123                 data->interval = 1000;
 124                 break;
 125         case RATE_CR2500:
 126         default:
 127                 data->interval = 2500;
 128                 break;
 129         }
 130         return 0;
 131 }
 132
 133 static int lm95245_set_conversion_rate(struct lm95245_data *data, long interval)
 134 {
 135         int ret, rate;
 136
 137         if (interval <= 63) {
 138                 interval = 63;
 139                 rate = RATE_CR0063;
 140         } else if (interval <= 364) {
 141                 interval = 364;
 142                 rate = RATE_CR0364;
 143         } else if (interval <= 1000) {
 144                 interval = 1000;
 145                 rate = RATE_CR1000;
 146         } else {
 147                 interval = 2500;
 148                 rate = RATE_CR2500;
 149         }
 150
 151         ret = regmap_write(data->regmap, LM95245_REG_RW_CONVERS_RATE, rate);
 152         if (ret < 0)
 153                 return ret;
 154
 155         data->interval = interval;
 156         return 0;
 157 }
 158
 159 static int lm95245_read_temp(struct device *dev, u32 attr, int channel,
 160                              long *val)
 161 {
 162         struct lm95245_data *data = dev_get_drvdata(dev);
 163         struct regmap *regmap = data->regmap;
 164         unsigned int regs[2];
 165         unsigned int regval;
 166         u8 regvals[2];
 167         int ret;
 168
 169         switch (attr) {
 170         case hwmon_temp_input:
 171                 regs[0] = channel ? LM95245_REG_R_REMOTE_TEMPL_S :
 172                                     LM95245_REG_R_LOCAL_TEMPL_S;
 173                 regs[1] = channel ? LM95245_REG_R_REMOTE_TEMPH_S :
 174                                     LM95245_REG_R_LOCAL_TEMPH_S;
 175                 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
 176                 if (ret < 0)
 177                         return ret;
 178                 /*
 179                  * Local temp is always signed.
 180                  * Remote temp has both signed and unsigned data.
 181                  * Use signed calculation for remote if signed bit is set
 182                  * or if reported temperature is below signed limit.
 183                  */
 184                 if (!channel || (regvals[1] & 0x80) || regvals[1] < 0x7f) {
 185                         *val = temp_from_reg_signed(regvals[1], regvals[0]);
 186                         return 0;
 187                 }
 188                 ret = regmap_bulk_read(regmap, LM95245_REG_R_REMOTE_TEMPH_U, regvals, 2);
 189                 if (ret)
 190                         return ret;
 191                 *val = temp_from_reg_unsigned(regvals[0], regvals[1]);
 192                 return 0;
 193         case hwmon_temp_max:
 194                 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT,
 195                                   &regval);
 196                 if (ret < 0)
 197                         return ret;
 198                 *val = regval * 1000;
 199                 return 0;
 200         case hwmon_temp_crit:
 201                 regs[0] = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
 202                                     LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
 203                 ret = regmap_read(regmap, regs[0], &regval);
 204                 if (ret < 0)
 205                         return ret;
 206                 *val = regval * 1000;
 207                 return 0;
 208         case hwmon_temp_max_hyst:
 209                 regs[0] = LM95245_REG_RW_REMOTE_OS_LIMIT;
 210                 regs[1] = LM95245_REG_RW_COMMON_HYSTERESIS;
 211                 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
 212                 if (ret < 0)
 213                         return ret;
 214                 *val = (regvals[0] - regvals[1]) * 1000;
 215                 return 0;
 216         case hwmon_temp_crit_hyst:
 217                 regs[0] = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
 218                                     LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
 219                 regs[1] = LM95245_REG_RW_COMMON_HYSTERESIS;
 220
 221                 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
 222                 if (ret < 0)
 223                         return ret;
 224                 *val = (regvals[0] - regvals[1]) * 1000;
 225                 return 0;
 226         case hwmon_temp_type:
 227                 ret = regmap_read(regmap, LM95245_REG_RW_CONFIG2, &regval);
 228                 if (ret < 0)
 229                         return ret;
 230                 *val = (regval & CFG2_REMOTE_TT) ? 1 : 2;
 231                 return 0;
 232         case hwmon_temp_offset:
 233                 ret = regmap_bulk_read(regmap, LM95245_REG_RW_REMOTE_OFFH, regvals, 2);
 234                 if (ret < 0)
 235                         return ret;
 236                 *val = temp_from_reg_signed(regvals[0], regvals[1]);
 237                 return 0;
 238         case hwmon_temp_max_alarm:
 239                 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, &regval);
 240                 if (ret < 0)
 241                         return ret;
 242                 *val = !!(regval & STATUS1_ROS);
 243                 return 0;
 244         case hwmon_temp_crit_alarm:
 245                 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, &regval);
 246                 if (ret < 0)
 247                         return ret;
 248                 *val = !!(regval & (channel ? STATUS1_RTCRIT : STATUS1_LOC));
 249                 return 0;
 250         case hwmon_temp_fault:
 251                 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, &regval);
 252                 if (ret < 0)
 253                         return ret;
 254                 *val = !!(regval & STATUS1_DIODE_FAULT);
 255                 return 0;
 256         default:
 257                 return -EOPNOTSUPP;
 258         }
 259 }
 260
 261 static int lm95245_write_temp(struct device *dev, u32 attr, int channel,
 262                               long val)
 263 {
 264         struct lm95245_data *data = dev_get_drvdata(dev);
 265         struct regmap *regmap = data->regmap;
 266         unsigned int regval;
 267         u8 regvals[2];
 268         int ret, reg;
 269
 270         switch (attr) {
 271         case hwmon_temp_max:
 272                 val = clamp_val(val / 1000, 0, 255);
 273                 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, val);
 274                 return ret;
 275         case hwmon_temp_crit:
 276                 reg = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
 277                                 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
 278                 val = clamp_val(val / 1000, 0, channel ? 255 : 127);
 279                 ret = regmap_write(regmap, reg, val);
 280                 return ret;
 281         case hwmon_temp_crit_hyst:
 282                 mutex_lock(&data->update_lock);
 283                 ret = regmap_read(regmap, LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
 284                                   &regval);
 285                 if (ret < 0) {
 286                         mutex_unlock(&data->update_lock);
 287                         return ret;
 288                 }
 289                 /* Clamp to reasonable range to prevent overflow */
 290                 val = clamp_val(val, -1000000, 1000000);
 291                 val = regval - val / 1000;
 292                 val = clamp_val(val, 0, 31);
 293                 ret = regmap_write(regmap, LM95245_REG_RW_COMMON_HYSTERESIS,
 294                                    val);
 295                 mutex_unlock(&data->update_lock);
 296                 return ret;
 297         case hwmon_temp_offset:
 298                 val = clamp_val(val, -128000, 127875);
 299                 val = val * 256 / 1000;
 300                 regvals[0] = val >> 8;
 301                 regvals[1] = val & 0xe0;
 302
 303                 ret = regmap_bulk_write(regmap, LM95245_REG_RW_REMOTE_OFFH, regvals, 2);
 304                 return ret;
 305         case hwmon_temp_type:
 306                 if (val != 1 && val != 2)
 307                         return -EINVAL;
 308                 ret = regmap_update_bits(regmap, LM95245_REG_RW_CONFIG2,
 309                                          CFG2_REMOTE_TT,
 310                                          val == 1 ? CFG2_REMOTE_TT : 0);
 311                 return ret;
 312         default:
 313                 return -EOPNOTSUPP;
 314         }
 315 }
 316
 317 static int lm95245_read_chip(struct device *dev, u32 attr, int channel,
 318                              long *val)
 319 {
 320         struct lm95245_data *data = dev_get_drvdata(dev);
 321
 322         switch (attr) {
 323         case hwmon_chip_update_interval:
 324                 *val = data->interval;
 325                 return 0;
 326         default:
 327                 return -EOPNOTSUPP;
 328         }
 329 }
 330
 331 static int lm95245_write_chip(struct device *dev, u32 attr, int channel,
 332                               long val)
 333 {
 334         struct lm95245_data *data = dev_get_drvdata(dev);
 335         int ret;
 336
 337         switch (attr) {
 338         case hwmon_chip_update_interval:
 339                 mutex_lock(&data->update_lock);
 340                 ret = lm95245_set_conversion_rate(data, val);
 341                 mutex_unlock(&data->update_lock);
 342                 return ret;
 343         default:
 344                 return -EOPNOTSUPP;
 345         }
 346 }
 347
 348 static int lm95245_read(struct device *dev, enum hwmon_sensor_types type,
 349                         u32 attr, int channel, long *val)
 350 {
 351         switch (type) {
 352         case hwmon_chip:
 353                 return lm95245_read_chip(dev, attr, channel, val);
 354         case hwmon_temp:
 355                 return lm95245_read_temp(dev, attr, channel, val);
 356         default:
 357                 return -EOPNOTSUPP;
 358         }
 359 }
 360
 361 static int lm95245_write(struct device *dev, enum hwmon_sensor_types type,
 362                          u32 attr, int channel, long val)
 363 {
 364         switch (type) {
 365         case hwmon_chip:
 366                 return lm95245_write_chip(dev, attr, channel, val);
 367         case hwmon_temp:
 368                 return lm95245_write_temp(dev, attr, channel, val);
 369         default:
 370                 return -EOPNOTSUPP;
 371         }
 372 }
 373
 374 static umode_t lm95245_temp_is_visible(const void *data, u32 attr, int channel)
 375 {
 376         switch (attr) {
 377         case hwmon_temp_input:
 378         case hwmon_temp_max_alarm:
 379         case hwmon_temp_max_hyst:
 380         case hwmon_temp_crit_alarm:
 381         case hwmon_temp_fault:
 382                 return 0444;
 383         case hwmon_temp_type:
 384         case hwmon_temp_max:
 385         case hwmon_temp_crit:
 386         case hwmon_temp_offset:
 387                 return 0644;
 388         case hwmon_temp_crit_hyst:
 389                 return (channel == 0) ? 0644 : 0444;
 390         default:
 391                 return 0;
 392         }
 393 }
 394
 395 static umode_t lm95245_is_visible(const void *data,
 396                                   enum hwmon_sensor_types type,
 397                                   u32 attr, int channel)
 398 {
 399         switch (type) {
 400         case hwmon_chip:
 401                 switch (attr) {
 402                 case hwmon_chip_update_interval:
 403                         return 0644;
 404                 default:
 405                         return 0;
 406                 }
 407         case hwmon_temp:
 408                 return lm95245_temp_is_visible(data, attr, channel);
 409         default:
 410                 return 0;
 411         }
 412 }
 413
 414 /* Return 0 if detection is successful, -ENODEV otherwise */
 415 static int lm95245_detect(struct i2c_client *new_client,
 416                           struct i2c_board_info *info)
 417 {
 418         struct i2c_adapter *adapter = new_client->adapter;
 419         int address = new_client->addr;
 420         const char *name;
 421         int rev, id;
 422
 423         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 424                 return -ENODEV;
 425
 426         id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID);
 427         if (id != MANUFACTURER_ID)
 428                 return -ENODEV;
 429
 430         rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID);
 431         switch (rev) {
 432         case LM95235_REVISION:
 433                 if (address != 0x18 && address != 0x29 && address != 0x4c)
 434                         return -ENODEV;
 435                 name = "lm95235";
 436                 break;
 437         case LM95245_REVISION:
 438                 name = "lm95245";
 439                 break;
 440         default:
 441                 return -ENODEV;
 442         }
 443
 444         strscpy(info->type, name, I2C_NAME_SIZE);
 445         return 0;
 446 }
 447
 448 static int lm95245_init_client(struct lm95245_data *data)
 449 {
 450         int ret;
 451
 452         ret = lm95245_read_conversion_rate(data);
 453         if (ret < 0)
 454                 return ret;
 455
 456         return regmap_update_bits(data->regmap, LM95245_REG_RW_CONFIG1,
 457                                   CFG_STOP, 0);
 458 }
 459
 460 static bool lm95245_is_writeable_reg(struct device *dev, unsigned int reg)
 461 {
 462         switch (reg) {
 463         case LM95245_REG_RW_CONFIG1:
 464         case LM95245_REG_RW_CONVERS_RATE:
 465         case LM95245_REG_W_ONE_SHOT:
 466         case LM95245_REG_RW_CONFIG2:
 467         case LM95245_REG_RW_REMOTE_OFFH:
 468         case LM95245_REG_RW_REMOTE_OFFL:
 469         case LM95245_REG_RW_REMOTE_OS_LIMIT:
 470         case LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT:
 471         case LM95245_REG_RW_REMOTE_TCRIT_LIMIT:
 472         case LM95245_REG_RW_COMMON_HYSTERESIS:
 473                 return true;
 474         default:
 475                 return false;
 476         }
 477 }
 478
 479 static bool lm95245_is_volatile_reg(struct device *dev, unsigned int reg)
 480 {
 481         switch (reg) {
 482         case LM95245_REG_R_STATUS1:
 483         case LM95245_REG_R_STATUS2:
 484         case LM95245_REG_R_LOCAL_TEMPH_S:
 485         case LM95245_REG_R_LOCAL_TEMPL_S:
 486         case LM95245_REG_R_REMOTE_TEMPH_S:
 487         case LM95245_REG_R_REMOTE_TEMPL_S:
 488         case LM95245_REG_R_REMOTE_TEMPH_U:
 489         case LM95245_REG_R_REMOTE_TEMPL_U:
 490                 return true;
 491         default:
 492                 return false;
 493         }
 494 }
 495
 496 static const struct regmap_config lm95245_regmap_config = {
 497         .reg_bits = 8,
 498         .val_bits = 8,
 499         .writeable_reg = lm95245_is_writeable_reg,
 500         .volatile_reg = lm95245_is_volatile_reg,
 501         .cache_type = REGCACHE_MAPLE,
 502         .use_single_read = true,
 503         .use_single_write = true,
 504 };
 505
 506 static const struct hwmon_channel_info * const lm95245_info[] = {
 507         HWMON_CHANNEL_INFO(chip,
 508                            HWMON_C_UPDATE_INTERVAL),
 509         HWMON_CHANNEL_INFO(temp,
 510                            HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_HYST |
 511                            HWMON_T_CRIT_ALARM,
 512                            HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
 513                            HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_FAULT |
 514                            HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM |
 515                            HWMON_T_TYPE | HWMON_T_OFFSET),
 516         NULL
 517 };
 518
 519 static const struct hwmon_ops lm95245_hwmon_ops = {
 520         .is_visible = lm95245_is_visible,
 521         .read = lm95245_read,
 522         .write = lm95245_write,
 523 };
 524
 525 static const struct hwmon_chip_info lm95245_chip_info = {
 526         .ops = &lm95245_hwmon_ops,
 527         .info = lm95245_info,
 528 };
 529
 530 static int lm95245_probe(struct i2c_client *client)
 531 {
 532         struct device *dev = &client->dev;
 533         struct lm95245_data *data;
 534         struct device *hwmon_dev;
 535         int ret;
 536
 537         data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL);
 538         if (!data)
 539                 return -ENOMEM;
 540
 541         data->regmap = devm_regmap_init_i2c(client, &lm95245_regmap_config);
 542         if (IS_ERR(data->regmap))
 543                 return PTR_ERR(data->regmap);
 544
 545         mutex_init(&data->update_lock);
 546
 547         /* Initialize the LM95245 chip */
 548         ret = lm95245_init_client(data);
 549         if (ret < 0)
 550                 return ret;
 551
 552         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 553                                                          data,
 554                                                          &lm95245_chip_info,
 555                                                          NULL);
 556         return PTR_ERR_OR_ZERO(hwmon_dev);
 557 }
 558
 559 /* Driver data (common to all clients) */
 560 static const struct i2c_device_id lm95245_id[] = {
 561         { "lm95235" },
 562         { "lm95245" },
 563         { }
 564 };
 565 MODULE_DEVICE_TABLE(i2c, lm95245_id);
 566
 567 static const struct of_device_id __maybe_unused lm95245_of_match[] = {
 568         { .compatible = "national,lm95235" },
 569         { .compatible = "national,lm95245" },
 570         { },
 571 };
 572 MODULE_DEVICE_TABLE(of, lm95245_of_match);
 573
 574 static struct i2c_driver lm95245_driver = {
 575         .class          = I2C_CLASS_HWMON,
 576         .driver = {
 577                 .name   = "lm95245",
 578                 .of_match_table = of_match_ptr(lm95245_of_match),
 579         },
 580         .probe          = lm95245_probe,
 581         .id_table       = lm95245_id,
 582         .detect         = lm95245_detect,
 583         .address_list   = normal_i2c,
 584 };
 585
 586 module_i2c_driver(lm95245_driver);
 587
 588 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
 589 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver");
 590 MODULE_LICENSE("GPL");