1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Sensirion SHT3x-DIS humidity and temperature sensor driver. 3 * The SHT3x comes in many different versions, this driver is for the 4 * I2C version only. 5 * 6 * Copyright (C) 2016 Sensirion AG, Switzerland 7 * Author: David Frey <david.frey@sensirion.com> 8 * Author: Pascal Sachs <pascal.sachs@sensirion.com> 9 */ 10 11 #include <asm/page.h> 12 #include <linux/crc8.h> 13 #include <linux/delay.h> 14 #include <linux/err.h> 15 #include <linux/hwmon.h> 16 #include <linux/hwmon-sysfs.h> 17 #include <linux/i2c.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/jiffies.h> 23 24 /* commands (high repeatability mode) */ 25 static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 }; 26 27 /* commands (medium repeatability mode) */ 28 static const unsigned char sht3x_cmd_measure_single_mpm[] = { 0x24, 0x0b }; 29 30 /* commands (low repeatability mode) */ 31 static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 }; 32 33 /* commands for periodic mode */ 34 static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 }; 35 static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 }; 36 37 /* commands for heater control */ 38 static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d }; 39 static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 }; 40 41 /* other commands */ 42 static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d }; 43 static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 }; 44 45 /* delays for single-shot mode i2c commands, both in us */ 46 #define SHT3X_SINGLE_WAIT_TIME_HPM 15000 47 #define SHT3X_SINGLE_WAIT_TIME_MPM 6000 48 #define SHT3X_SINGLE_WAIT_TIME_LPM 4000 49 50 #define SHT3X_WORD_LEN 2 51 #define SHT3X_CMD_LENGTH 2 52 #define SHT3X_CRC8_LEN 1 53 #define SHT3X_RESPONSE_LENGTH 6 54 #define SHT3X_CRC8_POLYNOMIAL 0x31 55 #define SHT3X_CRC8_INIT 0xFF 56 #define SHT3X_MIN_TEMPERATURE -45000 57 #define SHT3X_MAX_TEMPERATURE 130000 58 #define SHT3X_MIN_HUMIDITY 0 59 #define SHT3X_MAX_HUMIDITY 100000 60 61 enum sht3x_chips { 62 sht3x, 63 sts3x, 64 }; 65 66 enum sht3x_limits { 67 limit_max = 0, 68 limit_max_hyst, 69 limit_min, 70 limit_min_hyst, 71 }; 72 73 enum sht3x_repeatability { 74 low_repeatability, 75 medium_repeatability, 76 high_repeatability, 77 }; 78 79 DECLARE_CRC8_TABLE(sht3x_crc8_table); 80 81 /* periodic measure commands (high repeatability mode) */ 82 static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = { 83 /* 0.5 measurements per second */ 84 {0x20, 0x32}, 85 /* 1 measurements per second */ 86 {0x21, 0x30}, 87 /* 2 measurements per second */ 88 {0x22, 0x36}, 89 /* 4 measurements per second */ 90 {0x23, 0x34}, 91 /* 10 measurements per second */ 92 {0x27, 0x37}, 93 }; 94 95 /* periodic measure commands (medium repeatability) */ 96 static const char periodic_measure_commands_mpm[][SHT3X_CMD_LENGTH] = { 97 /* 0.5 measurements per second */ 98 {0x20, 0x24}, 99 /* 1 measurements per second */ 100 {0x21, 0x26}, 101 /* 2 measurements per second */ 102 {0x22, 0x20}, 103 /* 4 measurements per second */ 104 {0x23, 0x22}, 105 /* 10 measurements per second */ 106 {0x27, 0x21}, 107 }; 108 109 /* periodic measure commands (low repeatability mode) */ 110 static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = { 111 /* 0.5 measurements per second */ 112 {0x20, 0x2f}, 113 /* 1 measurements per second */ 114 {0x21, 0x2d}, 115 /* 2 measurements per second */ 116 {0x22, 0x2b}, 117 /* 4 measurements per second */ 118 {0x23, 0x29}, 119 /* 10 measurements per second */ 120 {0x27, 0x2a}, 121 }; 122 123 struct sht3x_limit_commands { 124 const char read_command[SHT3X_CMD_LENGTH]; 125 const char write_command[SHT3X_CMD_LENGTH]; 126 }; 127 128 static const struct sht3x_limit_commands limit_commands[] = { 129 /* temp1_max, humidity1_max */ 130 [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} }, 131 /* temp_1_max_hyst, humidity1_max_hyst */ 132 [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} }, 133 /* temp1_min, humidity1_min */ 134 [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} }, 135 /* temp_1_min_hyst, humidity1_min_hyst */ 136 [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} }, 137 }; 138 139 #define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands) 140 141 static const u16 mode_to_update_interval[] = { 142 0, 143 2000, 144 1000, 145 500, 146 250, 147 100, 148 }; 149 150 static const struct hwmon_channel_info * const sht3x_channel_info[] = { 151 HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL), 152 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | 153 HWMON_T_MIN_HYST | HWMON_T_MAX | 154 HWMON_T_MAX_HYST | HWMON_T_ALARM), 155 HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN | 156 HWMON_H_MIN_HYST | HWMON_H_MAX | 157 HWMON_H_MAX_HYST | HWMON_H_ALARM), 158 NULL, 159 }; 160 161 struct sht3x_data { 162 struct i2c_client *client; 163 enum sht3x_chips chip_id; 164 struct mutex i2c_lock; /* lock for sending i2c commands */ 165 struct mutex data_lock; /* lock for updating driver data */ 166 167 u8 mode; 168 const unsigned char *command; 169 u32 wait_time; /* in us*/ 170 unsigned long last_update; /* last update in periodic mode*/ 171 enum sht3x_repeatability repeatability; 172 173 /* 174 * cached values for temperature and humidity and limits 175 * the limits arrays have the following order: 176 * max, max_hyst, min, min_hyst 177 */ 178 int temperature; 179 int temperature_limits[SHT3X_NUM_LIMIT_CMD]; 180 u32 humidity; 181 u32 humidity_limits[SHT3X_NUM_LIMIT_CMD]; 182 }; 183 184 static u8 get_mode_from_update_interval(u16 value) 185 { 186 size_t index; 187 u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval); 188 189 if (value == 0) 190 return 0; 191 192 /* find next faster update interval */ 193 for (index = 1; index < number_of_modes; index++) { 194 if (mode_to_update_interval[index] <= value) 195 return index; 196 } 197 198 return number_of_modes - 1; 199 } 200 201 static int sht3x_read_from_command(struct i2c_client *client, 202 struct sht3x_data *data, 203 const char *command, 204 char *buf, int length, u32 wait_time) 205 { 206 int ret; 207 208 mutex_lock(&data->i2c_lock); 209 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); 210 211 if (ret != SHT3X_CMD_LENGTH) { 212 ret = ret < 0 ? ret : -EIO; 213 goto out; 214 } 215 216 if (wait_time) 217 usleep_range(wait_time, wait_time + 1000); 218 219 ret = i2c_master_recv(client, buf, length); 220 if (ret != length) { 221 ret = ret < 0 ? ret : -EIO; 222 goto out; 223 } 224 225 ret = 0; 226 out: 227 mutex_unlock(&data->i2c_lock); 228 return ret; 229 } 230 231 static int sht3x_extract_temperature(u16 raw) 232 { 233 /* 234 * From datasheet: 235 * T = -45 + 175 * ST / 2^16 236 * Adapted for integer fixed point (3 digit) arithmetic. 237 */ 238 return ((21875 * (int)raw) >> 13) - 45000; 239 } 240 241 static u32 sht3x_extract_humidity(u16 raw) 242 { 243 /* 244 * From datasheet: 245 * RH = 100 * SRH / 2^16 246 * Adapted for integer fixed point (3 digit) arithmetic. 247 */ 248 return (12500 * (u32)raw) >> 13; 249 } 250 251 static struct sht3x_data *sht3x_update_client(struct device *dev) 252 { 253 struct sht3x_data *data = dev_get_drvdata(dev); 254 struct i2c_client *client = data->client; 255 u16 interval_ms = mode_to_update_interval[data->mode]; 256 unsigned long interval_jiffies = msecs_to_jiffies(interval_ms); 257 unsigned char buf[SHT3X_RESPONSE_LENGTH]; 258 u16 val; 259 int ret = 0; 260 261 mutex_lock(&data->data_lock); 262 /* 263 * Only update cached readings once per update interval in periodic 264 * mode. In single shot mode the sensor measures values on demand, so 265 * every time the sysfs interface is called, a measurement is triggered. 266 * In periodic mode however, the measurement process is handled 267 * internally by the sensor and reading out sensor values only makes 268 * sense if a new reading is available. 269 */ 270 if (time_after(jiffies, data->last_update + interval_jiffies)) { 271 ret = sht3x_read_from_command(client, data, data->command, buf, 272 sizeof(buf), data->wait_time); 273 if (ret) 274 goto out; 275 276 val = be16_to_cpup((__be16 *)buf); 277 data->temperature = sht3x_extract_temperature(val); 278 val = be16_to_cpup((__be16 *)(buf + 3)); 279 data->humidity = sht3x_extract_humidity(val); 280 data->last_update = jiffies; 281 } 282 283 out: 284 mutex_unlock(&data->data_lock); 285 if (ret) 286 return ERR_PTR(ret); 287 288 return data; 289 } 290 291 static int temp1_input_read(struct device *dev) 292 { 293 struct sht3x_data *data = sht3x_update_client(dev); 294 295 if (IS_ERR(data)) 296 return PTR_ERR(data); 297 298 return data->temperature; 299 } 300 301 static int humidity1_input_read(struct device *dev) 302 { 303 struct sht3x_data *data = sht3x_update_client(dev); 304 305 if (IS_ERR(data)) 306 return PTR_ERR(data); 307 308 return data->humidity; 309 } 310 311 /* 312 * limits_update must only be called from probe or with data_lock held 313 */ 314 static int limits_update(struct sht3x_data *data) 315 { 316 int ret; 317 u8 index; 318 int temperature; 319 u32 humidity; 320 u16 raw; 321 char buffer[SHT3X_RESPONSE_LENGTH]; 322 const struct sht3x_limit_commands *commands; 323 struct i2c_client *client = data->client; 324 325 for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) { 326 commands = &limit_commands[index]; 327 ret = sht3x_read_from_command(client, data, 328 commands->read_command, buffer, 329 SHT3X_RESPONSE_LENGTH, 0); 330 331 if (ret) 332 return ret; 333 334 raw = be16_to_cpup((__be16 *)buffer); 335 temperature = sht3x_extract_temperature((raw & 0x01ff) << 7); 336 humidity = sht3x_extract_humidity(raw & 0xfe00); 337 data->temperature_limits[index] = temperature; 338 data->humidity_limits[index] = humidity; 339 } 340 341 return ret; 342 } 343 344 static int temp1_limit_read(struct device *dev, int index) 345 { 346 struct sht3x_data *data = dev_get_drvdata(dev); 347 348 return data->temperature_limits[index]; 349 } 350 351 static int humidity1_limit_read(struct device *dev, int index) 352 { 353 struct sht3x_data *data = dev_get_drvdata(dev); 354 355 return data->humidity_limits[index]; 356 } 357 358 /* 359 * limit_write must only be called with data_lock held 360 */ 361 static size_t limit_write(struct device *dev, 362 u8 index, 363 int temperature, 364 u32 humidity) 365 { 366 char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 367 char *position = buffer; 368 int ret; 369 u16 raw; 370 struct sht3x_data *data = dev_get_drvdata(dev); 371 struct i2c_client *client = data->client; 372 const struct sht3x_limit_commands *commands; 373 374 commands = &limit_commands[index]; 375 376 memcpy(position, commands->write_command, SHT3X_CMD_LENGTH); 377 position += SHT3X_CMD_LENGTH; 378 /* 379 * ST = (T + 45) / 175 * 2^16 380 * SRH = RH / 100 * 2^16 381 * adapted for fixed point arithmetic and packed the same as 382 * in limit_read() 383 */ 384 raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7); 385 raw |= ((humidity * 42950) >> 16) & 0xfe00; 386 387 *((__be16 *)position) = cpu_to_be16(raw); 388 position += SHT3X_WORD_LEN; 389 *position = crc8(sht3x_crc8_table, 390 position - SHT3X_WORD_LEN, 391 SHT3X_WORD_LEN, 392 SHT3X_CRC8_INIT); 393 394 mutex_lock(&data->i2c_lock); 395 ret = i2c_master_send(client, buffer, sizeof(buffer)); 396 mutex_unlock(&data->i2c_lock); 397 398 if (ret != sizeof(buffer)) 399 return ret < 0 ? ret : -EIO; 400 401 data->temperature_limits[index] = temperature; 402 data->humidity_limits[index] = humidity; 403 404 return 0; 405 } 406 407 static int temp1_limit_write(struct device *dev, int index, int val) 408 { 409 int temperature; 410 int ret; 411 struct sht3x_data *data = dev_get_drvdata(dev); 412 413 temperature = clamp_val(val, SHT3X_MIN_TEMPERATURE, 414 SHT3X_MAX_TEMPERATURE); 415 mutex_lock(&data->data_lock); 416 ret = limit_write(dev, index, temperature, 417 data->humidity_limits[index]); 418 mutex_unlock(&data->data_lock); 419 420 return ret; 421 } 422 423 static int humidity1_limit_write(struct device *dev, int index, int val) 424 { 425 u32 humidity; 426 int ret; 427 struct sht3x_data *data = dev_get_drvdata(dev); 428 429 humidity = clamp_val(val, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY); 430 mutex_lock(&data->data_lock); 431 ret = limit_write(dev, index, data->temperature_limits[index], 432 humidity); 433 mutex_unlock(&data->data_lock); 434 435 return ret; 436 } 437 438 static void sht3x_select_command(struct sht3x_data *data) 439 { 440 /* 441 * For single-shot mode, only non blocking mode is support, 442 * we have to wait ourselves for result. 443 */ 444 if (data->mode > 0) { 445 data->command = sht3x_cmd_measure_periodic_mode; 446 data->wait_time = 0; 447 } else { 448 if (data->repeatability == high_repeatability) { 449 data->command = sht3x_cmd_measure_single_hpm; 450 data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM; 451 } else if (data->repeatability == medium_repeatability) { 452 data->command = sht3x_cmd_measure_single_mpm; 453 data->wait_time = SHT3X_SINGLE_WAIT_TIME_MPM; 454 } else { 455 data->command = sht3x_cmd_measure_single_lpm; 456 data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM; 457 } 458 } 459 } 460 461 static int status_register_read(struct device *dev, 462 char *buffer, int length) 463 { 464 int ret; 465 struct sht3x_data *data = dev_get_drvdata(dev); 466 struct i2c_client *client = data->client; 467 468 ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg, 469 buffer, length, 0); 470 471 return ret; 472 } 473 474 static int temp1_alarm_read(struct device *dev) 475 { 476 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 477 int ret; 478 479 ret = status_register_read(dev, buffer, 480 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 481 if (ret) 482 return ret; 483 484 return !!(buffer[0] & 0x04); 485 } 486 487 static int humidity1_alarm_read(struct device *dev) 488 { 489 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 490 int ret; 491 492 ret = status_register_read(dev, buffer, 493 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 494 if (ret) 495 return ret; 496 497 return !!(buffer[0] & 0x08); 498 } 499 500 static ssize_t heater_enable_show(struct device *dev, 501 struct device_attribute *attr, 502 char *buf) 503 { 504 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; 505 int ret; 506 507 ret = status_register_read(dev, buffer, 508 SHT3X_WORD_LEN + SHT3X_CRC8_LEN); 509 if (ret) 510 return ret; 511 512 return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x20)); 513 } 514 515 static ssize_t heater_enable_store(struct device *dev, 516 struct device_attribute *attr, 517 const char *buf, 518 size_t count) 519 { 520 struct sht3x_data *data = dev_get_drvdata(dev); 521 struct i2c_client *client = data->client; 522 int ret; 523 bool status; 524 525 ret = kstrtobool(buf, &status); 526 if (ret) 527 return ret; 528 529 mutex_lock(&data->i2c_lock); 530 531 if (status) 532 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on, 533 SHT3X_CMD_LENGTH); 534 else 535 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off, 536 SHT3X_CMD_LENGTH); 537 538 mutex_unlock(&data->i2c_lock); 539 540 return ret; 541 } 542 543 static int update_interval_read(struct device *dev) 544 { 545 struct sht3x_data *data = dev_get_drvdata(dev); 546 547 return mode_to_update_interval[data->mode]; 548 } 549 550 static int update_interval_write(struct device *dev, int val) 551 { 552 u8 mode; 553 int ret; 554 const char *command; 555 struct sht3x_data *data = dev_get_drvdata(dev); 556 struct i2c_client *client = data->client; 557 558 mode = get_mode_from_update_interval(val); 559 560 mutex_lock(&data->data_lock); 561 /* mode did not change */ 562 if (mode == data->mode) { 563 mutex_unlock(&data->data_lock); 564 return 0; 565 } 566 567 mutex_lock(&data->i2c_lock); 568 /* 569 * Abort periodic measure mode. 570 * To do any changes to the configuration while in periodic mode, we 571 * have to send a break command to the sensor, which then falls back 572 * to single shot (mode = 0). 573 */ 574 if (data->mode > 0) { 575 ret = i2c_master_send(client, sht3x_cmd_break, 576 SHT3X_CMD_LENGTH); 577 if (ret != SHT3X_CMD_LENGTH) 578 goto out; 579 data->mode = 0; 580 } 581 582 if (mode > 0) { 583 if (data->repeatability == high_repeatability) 584 command = periodic_measure_commands_hpm[mode - 1]; 585 else if (data->repeatability == medium_repeatability) 586 command = periodic_measure_commands_mpm[mode - 1]; 587 else 588 command = periodic_measure_commands_lpm[mode - 1]; 589 590 /* select mode */ 591 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); 592 if (ret != SHT3X_CMD_LENGTH) 593 goto out; 594 } 595 596 /* select mode and command */ 597 data->mode = mode; 598 sht3x_select_command(data); 599 600 out: 601 mutex_unlock(&data->i2c_lock); 602 mutex_unlock(&data->data_lock); 603 if (ret != SHT3X_CMD_LENGTH) 604 return ret < 0 ? ret : -EIO; 605 606 return 0; 607 } 608 609 static ssize_t repeatability_show(struct device *dev, 610 struct device_attribute *attr, 611 char *buf) 612 { 613 struct sht3x_data *data = dev_get_drvdata(dev); 614 615 return sysfs_emit(buf, "%d\n", data->repeatability); 616 } 617 618 static ssize_t repeatability_store(struct device *dev, 619 struct device_attribute *attr, 620 const char *buf, 621 size_t count) 622 { 623 int ret; 624 u8 val; 625 626 struct sht3x_data *data = dev_get_drvdata(dev); 627 628 ret = kstrtou8(buf, 0, &val); 629 if (ret) 630 return ret; 631 632 if (val > 2) 633 return -EINVAL; 634 635 data->repeatability = val; 636 637 return count; 638 } 639 640 static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0); 641 static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0); 642 643 static struct attribute *sht3x_attrs[] = { 644 &sensor_dev_attr_heater_enable.dev_attr.attr, 645 &sensor_dev_attr_repeatability.dev_attr.attr, 646 NULL 647 }; 648 649 ATTRIBUTE_GROUPS(sht3x); 650 651 static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type, 652 u32 attr, int channel) 653 { 654 const struct sht3x_data *chip_data = data; 655 656 switch (type) { 657 case hwmon_chip: 658 switch (attr) { 659 case hwmon_chip_update_interval: 660 return 0644; 661 default: 662 break; 663 } 664 break; 665 case hwmon_temp: 666 switch (attr) { 667 case hwmon_temp_input: 668 case hwmon_temp_alarm: 669 return 0444; 670 case hwmon_temp_max: 671 case hwmon_temp_max_hyst: 672 case hwmon_temp_min: 673 case hwmon_temp_min_hyst: 674 return 0644; 675 default: 676 break; 677 } 678 break; 679 case hwmon_humidity: 680 if (chip_data->chip_id == sts3x) 681 break; 682 switch (attr) { 683 case hwmon_humidity_input: 684 case hwmon_humidity_alarm: 685 return 0444; 686 case hwmon_humidity_max: 687 case hwmon_humidity_max_hyst: 688 case hwmon_humidity_min: 689 case hwmon_humidity_min_hyst: 690 return 0644; 691 default: 692 break; 693 } 694 break; 695 default: 696 break; 697 } 698 699 return 0; 700 } 701 702 static int sht3x_read(struct device *dev, enum hwmon_sensor_types type, 703 u32 attr, int channel, long *val) 704 { 705 enum sht3x_limits index; 706 707 switch (type) { 708 case hwmon_chip: 709 switch (attr) { 710 case hwmon_chip_update_interval: 711 *val = update_interval_read(dev); 712 break; 713 default: 714 return -EOPNOTSUPP; 715 } 716 break; 717 case hwmon_temp: 718 switch (attr) { 719 case hwmon_temp_input: 720 *val = temp1_input_read(dev); 721 break; 722 case hwmon_temp_alarm: 723 *val = temp1_alarm_read(dev); 724 break; 725 case hwmon_temp_max: 726 index = limit_max; 727 *val = temp1_limit_read(dev, index); 728 break; 729 case hwmon_temp_max_hyst: 730 index = limit_max_hyst; 731 *val = temp1_limit_read(dev, index); 732 break; 733 case hwmon_temp_min: 734 index = limit_min; 735 *val = temp1_limit_read(dev, index); 736 break; 737 case hwmon_temp_min_hyst: 738 index = limit_min_hyst; 739 *val = temp1_limit_read(dev, index); 740 break; 741 default: 742 return -EOPNOTSUPP; 743 } 744 break; 745 case hwmon_humidity: 746 switch (attr) { 747 case hwmon_humidity_input: 748 *val = humidity1_input_read(dev); 749 break; 750 case hwmon_humidity_alarm: 751 *val = humidity1_alarm_read(dev); 752 break; 753 case hwmon_humidity_max: 754 index = limit_max; 755 *val = humidity1_limit_read(dev, index); 756 break; 757 case hwmon_humidity_max_hyst: 758 index = limit_max_hyst; 759 *val = humidity1_limit_read(dev, index); 760 break; 761 case hwmon_humidity_min: 762 index = limit_min; 763 *val = humidity1_limit_read(dev, index); 764 break; 765 case hwmon_humidity_min_hyst: 766 index = limit_min_hyst; 767 *val = humidity1_limit_read(dev, index); 768 break; 769 default: 770 return -EOPNOTSUPP; 771 } 772 break; 773 default: 774 return -EOPNOTSUPP; 775 } 776 777 return 0; 778 } 779 780 static int sht3x_write(struct device *dev, enum hwmon_sensor_types type, 781 u32 attr, int channel, long val) 782 { 783 enum sht3x_limits index; 784 785 switch (type) { 786 case hwmon_chip: 787 switch (attr) { 788 case hwmon_chip_update_interval: 789 return update_interval_write(dev, val); 790 default: 791 return -EOPNOTSUPP; 792 } 793 case hwmon_temp: 794 switch (attr) { 795 case hwmon_temp_max: 796 index = limit_max; 797 break; 798 case hwmon_temp_max_hyst: 799 index = limit_max_hyst; 800 break; 801 case hwmon_temp_min: 802 index = limit_min; 803 break; 804 case hwmon_temp_min_hyst: 805 index = limit_min_hyst; 806 break; 807 default: 808 return -EOPNOTSUPP; 809 } 810 return temp1_limit_write(dev, index, val); 811 case hwmon_humidity: 812 switch (attr) { 813 case hwmon_humidity_max: 814 index = limit_max; 815 break; 816 case hwmon_humidity_max_hyst: 817 index = limit_max_hyst; 818 break; 819 case hwmon_humidity_min: 820 index = limit_min; 821 break; 822 case hwmon_humidity_min_hyst: 823 index = limit_min_hyst; 824 break; 825 default: 826 return -EOPNOTSUPP; 827 } 828 return humidity1_limit_write(dev, index, val); 829 default: 830 return -EOPNOTSUPP; 831 } 832 } 833 834 static const struct hwmon_ops sht3x_ops = { 835 .is_visible = sht3x_is_visible, 836 .read = sht3x_read, 837 .write = sht3x_write, 838 }; 839 840 static const struct hwmon_chip_info sht3x_chip_info = { 841 .ops = &sht3x_ops, 842 .info = sht3x_channel_info, 843 }; 844 845 /* device ID table */ 846 static const struct i2c_device_id sht3x_ids[] = { 847 {"sht3x", sht3x}, 848 {"sts3x", sts3x}, 849 {} 850 }; 851 852 MODULE_DEVICE_TABLE(i2c, sht3x_ids); 853 854 static int sht3x_probe(struct i2c_client *client) 855 { 856 int ret; 857 struct sht3x_data *data; 858 struct device *hwmon_dev; 859 struct i2c_adapter *adap = client->adapter; 860 struct device *dev = &client->dev; 861 862 /* 863 * we require full i2c support since the sht3x uses multi-byte read and 864 * writes as well as multi-byte commands which are not supported by 865 * the smbus protocol 866 */ 867 if (!i2c_check_functionality(adap, I2C_FUNC_I2C)) 868 return -ENODEV; 869 870 ret = i2c_master_send(client, sht3x_cmd_clear_status_reg, 871 SHT3X_CMD_LENGTH); 872 if (ret != SHT3X_CMD_LENGTH) 873 return ret < 0 ? ret : -ENODEV; 874 875 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 876 if (!data) 877 return -ENOMEM; 878 879 data->repeatability = high_repeatability; 880 data->mode = 0; 881 data->last_update = jiffies - msecs_to_jiffies(3000); 882 data->client = client; 883 data->chip_id = i2c_match_id(sht3x_ids, client)->driver_data; 884 crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL); 885 886 sht3x_select_command(data); 887 888 mutex_init(&data->i2c_lock); 889 mutex_init(&data->data_lock); 890 891 /* 892 * An attempt to read limits register too early 893 * causes a NACK response from the chip. 894 * Waiting for an empirical delay of 500 us solves the issue. 895 */ 896 usleep_range(500, 600); 897 898 ret = limits_update(data); 899 if (ret) 900 return ret; 901 902 hwmon_dev = devm_hwmon_device_register_with_info(dev, 903 client->name, 904 data, 905 &sht3x_chip_info, 906 sht3x_groups); 907 908 if (IS_ERR(hwmon_dev)) 909 dev_dbg(dev, "unable to register hwmon device\n"); 910 911 return PTR_ERR_OR_ZERO(hwmon_dev); 912 } 913 914 static struct i2c_driver sht3x_i2c_driver = { 915 .driver.name = "sht3x", 916 .probe = sht3x_probe, 917 .id_table = sht3x_ids, 918 }; 919 920 module_i2c_driver(sht3x_i2c_driver); 921 922 MODULE_AUTHOR("David Frey <david.frey@sensirion.com>"); 923 MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>"); 924 MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver"); 925 MODULE_LICENSE("GPL"); 926