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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 | // SPDX-License-Identifier: GPL-2.0-or-later /* Sensirion SHT3x-DIS humidity and temperature sensor driver. * The SHT3x comes in many different versions, this driver is for the * I2C version only. * * Copyright (C) 2016 Sensirion AG, Switzerland * Author: David Frey <david.frey@sensirion.com> * Author: Pascal Sachs <pascal.sachs@sensirion.com> */ #include <asm/page.h> #include <linux/crc8.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/jiffies.h> #include <linux/platform_data/sht3x.h> /* commands (high precision mode) */ static const unsigned char sht3x_cmd_measure_blocking_hpm[] = { 0x2c, 0x06 }; static const unsigned char sht3x_cmd_measure_nonblocking_hpm[] = { 0x24, 0x00 }; /* commands (low power mode) */ static const unsigned char sht3x_cmd_measure_blocking_lpm[] = { 0x2c, 0x10 }; static const unsigned char sht3x_cmd_measure_nonblocking_lpm[] = { 0x24, 0x16 }; /* commands for periodic mode */ static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 }; static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 }; /* commands for heater control */ static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d }; static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 }; /* other commands */ static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d }; static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 }; /* delays for non-blocking i2c commands, both in us */ #define SHT3X_NONBLOCKING_WAIT_TIME_HPM 15000 #define SHT3X_NONBLOCKING_WAIT_TIME_LPM 4000 #define SHT3X_WORD_LEN 2 #define SHT3X_CMD_LENGTH 2 #define SHT3X_CRC8_LEN 1 #define SHT3X_RESPONSE_LENGTH 6 #define SHT3X_CRC8_POLYNOMIAL 0x31 #define SHT3X_CRC8_INIT 0xFF #define SHT3X_MIN_TEMPERATURE -45000 #define SHT3X_MAX_TEMPERATURE 130000 #define SHT3X_MIN_HUMIDITY 0 #define SHT3X_MAX_HUMIDITY 100000 enum sht3x_chips { sht3x, sts3x, }; enum sht3x_limits { limit_max = 0, limit_max_hyst, limit_min, limit_min_hyst, }; DECLARE_CRC8_TABLE(sht3x_crc8_table); /* periodic measure commands (high precision mode) */ static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = { /* 0.5 measurements per second */ {0x20, 0x32}, /* 1 measurements per second */ {0x21, 0x30}, /* 2 measurements per second */ {0x22, 0x36}, /* 4 measurements per second */ {0x23, 0x34}, /* 10 measurements per second */ {0x27, 0x37}, }; /* periodic measure commands (low power mode) */ static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = { /* 0.5 measurements per second */ {0x20, 0x2f}, /* 1 measurements per second */ {0x21, 0x2d}, /* 2 measurements per second */ {0x22, 0x2b}, /* 4 measurements per second */ {0x23, 0x29}, /* 10 measurements per second */ {0x27, 0x2a}, }; struct sht3x_limit_commands { const char read_command[SHT3X_CMD_LENGTH]; const char write_command[SHT3X_CMD_LENGTH]; }; static const struct sht3x_limit_commands limit_commands[] = { /* temp1_max, humidity1_max */ [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} }, /* temp_1_max_hyst, humidity1_max_hyst */ [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} }, /* temp1_min, humidity1_min */ [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} }, /* temp_1_min_hyst, humidity1_min_hyst */ [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} }, }; #define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands) static const u16 mode_to_update_interval[] = { 0, 2000, 1000, 500, 250, 100, }; struct sht3x_data { struct i2c_client *client; struct mutex i2c_lock; /* lock for sending i2c commands */ struct mutex data_lock; /* lock for updating driver data */ u8 mode; const unsigned char *command; u32 wait_time; /* in us*/ unsigned long last_update; /* last update in periodic mode*/ struct sht3x_platform_data setup; /* * cached values for temperature and humidity and limits * the limits arrays have the following order: * max, max_hyst, min, min_hyst */ int temperature; int temperature_limits[SHT3X_NUM_LIMIT_CMD]; u32 humidity; u32 humidity_limits[SHT3X_NUM_LIMIT_CMD]; }; static u8 get_mode_from_update_interval(u16 value) { size_t index; u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval); if (value == 0) return 0; /* find next faster update interval */ for (index = 1; index < number_of_modes; index++) { if (mode_to_update_interval[index] <= value) return index; } return number_of_modes - 1; } static int sht3x_read_from_command(struct i2c_client *client, struct sht3x_data *data, const char *command, char *buf, int length, u32 wait_time) { int ret; mutex_lock(&data->i2c_lock); ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); if (ret != SHT3X_CMD_LENGTH) { ret = ret < 0 ? ret : -EIO; goto out; } if (wait_time) usleep_range(wait_time, wait_time + 1000); ret = i2c_master_recv(client, buf, length); if (ret != length) { ret = ret < 0 ? ret : -EIO; goto out; } ret = 0; out: mutex_unlock(&data->i2c_lock); return ret; } static int sht3x_extract_temperature(u16 raw) { /* * From datasheet: * T = -45 + 175 * ST / 2^16 * Adapted for integer fixed point (3 digit) arithmetic. */ return ((21875 * (int)raw) >> 13) - 45000; } static u32 sht3x_extract_humidity(u16 raw) { /* * From datasheet: * RH = 100 * SRH / 2^16 * Adapted for integer fixed point (3 digit) arithmetic. */ return (12500 * (u32)raw) >> 13; } static struct sht3x_data *sht3x_update_client(struct device *dev) { struct sht3x_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; u16 interval_ms = mode_to_update_interval[data->mode]; unsigned long interval_jiffies = msecs_to_jiffies(interval_ms); unsigned char buf[SHT3X_RESPONSE_LENGTH]; u16 val; int ret = 0; mutex_lock(&data->data_lock); /* * Only update cached readings once per update interval in periodic * mode. In single shot mode the sensor measures values on demand, so * every time the sysfs interface is called, a measurement is triggered. * In periodic mode however, the measurement process is handled * internally by the sensor and reading out sensor values only makes * sense if a new reading is available. */ if (time_after(jiffies, data->last_update + interval_jiffies)) { ret = sht3x_read_from_command(client, data, data->command, buf, sizeof(buf), data->wait_time); if (ret) goto out; val = be16_to_cpup((__be16 *)buf); data->temperature = sht3x_extract_temperature(val); val = be16_to_cpup((__be16 *)(buf + 3)); data->humidity = sht3x_extract_humidity(val); data->last_update = jiffies; } out: mutex_unlock(&data->data_lock); if (ret) return ERR_PTR(ret); return data; } /* sysfs attributes */ static ssize_t temp1_input_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sht3x_data *data = sht3x_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", data->temperature); } static ssize_t humidity1_input_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sht3x_data *data = sht3x_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%u\n", data->humidity); } /* * limits_update must only be called from probe or with data_lock held */ static int limits_update(struct sht3x_data *data) { int ret; u8 index; int temperature; u32 humidity; u16 raw; char buffer[SHT3X_RESPONSE_LENGTH]; const struct sht3x_limit_commands *commands; struct i2c_client *client = data->client; for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) { commands = &limit_commands[index]; ret = sht3x_read_from_command(client, data, commands->read_command, buffer, SHT3X_RESPONSE_LENGTH, 0); if (ret) return ret; raw = be16_to_cpup((__be16 *)buffer); temperature = sht3x_extract_temperature((raw & 0x01ff) << 7); humidity = sht3x_extract_humidity(raw & 0xfe00); data->temperature_limits[index] = temperature; data->humidity_limits[index] = humidity; } return ret; } static ssize_t temp1_limit_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sht3x_data *data = dev_get_drvdata(dev); u8 index = to_sensor_dev_attr(attr)->index; int temperature_limit = data->temperature_limits[index]; return scnprintf(buf, PAGE_SIZE, "%d\n", temperature_limit); } static ssize_t humidity1_limit_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sht3x_data *data = dev_get_drvdata(dev); u8 index = to_sensor_dev_attr(attr)->index; u32 humidity_limit = data->humidity_limits[index]; return scnprintf(buf, PAGE_SIZE, "%u\n", humidity_limit); } /* * limit_store must only be called with data_lock held */ static size_t limit_store(struct device *dev, size_t count, u8 index, int temperature, u32 humidity) { char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; char *position = buffer; int ret; u16 raw; struct sht3x_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; const struct sht3x_limit_commands *commands; commands = &limit_commands[index]; memcpy(position, commands->write_command, SHT3X_CMD_LENGTH); position += SHT3X_CMD_LENGTH; /* * ST = (T + 45) / 175 * 2^16 * SRH = RH / 100 * 2^16 * adapted for fixed point arithmetic and packed the same as * in limit_show() */ raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7); raw |= ((humidity * 42950) >> 16) & 0xfe00; *((__be16 *)position) = cpu_to_be16(raw); position += SHT3X_WORD_LEN; *position = crc8(sht3x_crc8_table, position - SHT3X_WORD_LEN, SHT3X_WORD_LEN, SHT3X_CRC8_INIT); mutex_lock(&data->i2c_lock); ret = i2c_master_send(client, buffer, sizeof(buffer)); mutex_unlock(&data->i2c_lock); if (ret != sizeof(buffer)) return ret < 0 ? ret : -EIO; data->temperature_limits[index] = temperature; data->humidity_limits[index] = humidity; return count; } static ssize_t temp1_limit_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int temperature; int ret; struct sht3x_data *data = dev_get_drvdata(dev); u8 index = to_sensor_dev_attr(attr)->index; ret = kstrtoint(buf, 0, &temperature); if (ret) return ret; temperature = clamp_val(temperature, SHT3X_MIN_TEMPERATURE, SHT3X_MAX_TEMPERATURE); mutex_lock(&data->data_lock); ret = limit_store(dev, count, index, temperature, data->humidity_limits[index]); mutex_unlock(&data->data_lock); return ret; } static ssize_t humidity1_limit_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { u32 humidity; int ret; struct sht3x_data *data = dev_get_drvdata(dev); u8 index = to_sensor_dev_attr(attr)->index; ret = kstrtou32(buf, 0, &humidity); if (ret) return ret; humidity = clamp_val(humidity, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY); mutex_lock(&data->data_lock); ret = limit_store(dev, count, index, data->temperature_limits[index], humidity); mutex_unlock(&data->data_lock); return ret; } static void sht3x_select_command(struct sht3x_data *data) { /* * In blocking mode (clock stretching mode) the I2C bus * is blocked for other traffic, thus the call to i2c_master_recv() * will wait until the data is ready. For non blocking mode, we * have to wait ourselves. */ if (data->mode > 0) { data->command = sht3x_cmd_measure_periodic_mode; data->wait_time = 0; } else if (data->setup.blocking_io) { data->command = data->setup.high_precision ? sht3x_cmd_measure_blocking_hpm : sht3x_cmd_measure_blocking_lpm; data->wait_time = 0; } else { if (data->setup.high_precision) { data->command = sht3x_cmd_measure_nonblocking_hpm; data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_HPM; } else { data->command = sht3x_cmd_measure_nonblocking_lpm; data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_LPM; } } } static int status_register_read(struct device *dev, struct device_attribute *attr, char *buffer, int length) { int ret; struct sht3x_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg, buffer, length, 0); return ret; } static ssize_t temp1_alarm_show(struct device *dev, struct device_attribute *attr, char *buf) { char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; int ret; ret = status_register_read(dev, attr, buffer, SHT3X_WORD_LEN + SHT3X_CRC8_LEN); if (ret) return ret; return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x04)); } static ssize_t humidity1_alarm_show(struct device *dev, struct device_attribute *attr, char *buf) { char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; int ret; ret = status_register_read(dev, attr, buffer, SHT3X_WORD_LEN + SHT3X_CRC8_LEN); if (ret) return ret; return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x08)); } static ssize_t heater_enable_show(struct device *dev, struct device_attribute *attr, char *buf) { char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN]; int ret; ret = status_register_read(dev, attr, buffer, SHT3X_WORD_LEN + SHT3X_CRC8_LEN); if (ret) return ret; return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x20)); } static ssize_t heater_enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct sht3x_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int ret; bool status; ret = kstrtobool(buf, &status); if (ret) return ret; mutex_lock(&data->i2c_lock); if (status) ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on, SHT3X_CMD_LENGTH); else ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off, SHT3X_CMD_LENGTH); mutex_unlock(&data->i2c_lock); return ret; } static ssize_t update_interval_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sht3x_data *data = dev_get_drvdata(dev); return scnprintf(buf, PAGE_SIZE, "%u\n", mode_to_update_interval[data->mode]); } static ssize_t update_interval_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { u16 update_interval; u8 mode; int ret; const char *command; struct sht3x_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; ret = kstrtou16(buf, 0, &update_interval); if (ret) return ret; mode = get_mode_from_update_interval(update_interval); mutex_lock(&data->data_lock); /* mode did not change */ if (mode == data->mode) { mutex_unlock(&data->data_lock); return count; } mutex_lock(&data->i2c_lock); /* * Abort periodic measure mode. * To do any changes to the configuration while in periodic mode, we * have to send a break command to the sensor, which then falls back * to single shot (mode = 0). */ if (data->mode > 0) { ret = i2c_master_send(client, sht3x_cmd_break, SHT3X_CMD_LENGTH); if (ret != SHT3X_CMD_LENGTH) goto out; data->mode = 0; } if (mode > 0) { if (data->setup.high_precision) command = periodic_measure_commands_hpm[mode - 1]; else command = periodic_measure_commands_lpm[mode - 1]; /* select mode */ ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH); if (ret != SHT3X_CMD_LENGTH) goto out; } /* select mode and command */ data->mode = mode; sht3x_select_command(data); out: mutex_unlock(&data->i2c_lock); mutex_unlock(&data->data_lock); if (ret != SHT3X_CMD_LENGTH) return ret < 0 ? ret : -EIO; return count; } static SENSOR_DEVICE_ATTR_RO(temp1_input, temp1_input, 0); static SENSOR_DEVICE_ATTR_RO(humidity1_input, humidity1_input, 0); static SENSOR_DEVICE_ATTR_RW(temp1_max, temp1_limit, limit_max); static SENSOR_DEVICE_ATTR_RW(humidity1_max, humidity1_limit, limit_max); static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp1_limit, limit_max_hyst); static SENSOR_DEVICE_ATTR_RW(humidity1_max_hyst, humidity1_limit, limit_max_hyst); static SENSOR_DEVICE_ATTR_RW(temp1_min, temp1_limit, limit_min); static SENSOR_DEVICE_ATTR_RW(humidity1_min, humidity1_limit, limit_min); static SENSOR_DEVICE_ATTR_RW(temp1_min_hyst, temp1_limit, limit_min_hyst); static SENSOR_DEVICE_ATTR_RW(humidity1_min_hyst, humidity1_limit, limit_min_hyst); static SENSOR_DEVICE_ATTR_RO(temp1_alarm, temp1_alarm, 0); static SENSOR_DEVICE_ATTR_RO(humidity1_alarm, humidity1_alarm, 0); static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0); static SENSOR_DEVICE_ATTR_RW(update_interval, update_interval, 0); static struct attribute *sht3x_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_humidity1_input.dev_attr.attr, &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, &sensor_dev_attr_humidity1_max.dev_attr.attr, &sensor_dev_attr_humidity1_max_hyst.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, &sensor_dev_attr_temp1_min_hyst.dev_attr.attr, &sensor_dev_attr_humidity1_min.dev_attr.attr, &sensor_dev_attr_humidity1_min_hyst.dev_attr.attr, &sensor_dev_attr_temp1_alarm.dev_attr.attr, &sensor_dev_attr_humidity1_alarm.dev_attr.attr, &sensor_dev_attr_heater_enable.dev_attr.attr, &sensor_dev_attr_update_interval.dev_attr.attr, NULL }; static struct attribute *sts3x_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, NULL }; ATTRIBUTE_GROUPS(sht3x); ATTRIBUTE_GROUPS(sts3x); static const struct i2c_device_id sht3x_ids[]; static int sht3x_probe(struct i2c_client *client) { int ret; struct sht3x_data *data; struct device *hwmon_dev; struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; const struct attribute_group **attribute_groups; /* * we require full i2c support since the sht3x uses multi-byte read and * writes as well as multi-byte commands which are not supported by * the smbus protocol */ if (!i2c_check_functionality(adap, I2C_FUNC_I2C)) return -ENODEV; ret = i2c_master_send(client, sht3x_cmd_clear_status_reg, SHT3X_CMD_LENGTH); if (ret != SHT3X_CMD_LENGTH) return ret < 0 ? ret : -ENODEV; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->setup.blocking_io = false; data->setup.high_precision = true; data->mode = 0; data->last_update = jiffies - msecs_to_jiffies(3000); data->client = client; crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL); if (client->dev.platform_data) data->setup = *(struct sht3x_platform_data *)dev->platform_data; sht3x_select_command(data); mutex_init(&data->i2c_lock); mutex_init(&data->data_lock); /* * An attempt to read limits register too early * causes a NACK response from the chip. * Waiting for an empirical delay of 500 us solves the issue. */ usleep_range(500, 600); ret = limits_update(data); if (ret) return ret; if (i2c_match_id(sht3x_ids, client)->driver_data == sts3x) attribute_groups = sts3x_groups; else attribute_groups = sht3x_groups; hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, attribute_groups); if (IS_ERR(hwmon_dev)) dev_dbg(dev, "unable to register hwmon device\n"); return PTR_ERR_OR_ZERO(hwmon_dev); } /* device ID table */ static const struct i2c_device_id sht3x_ids[] = { {"sht3x", sht3x}, {"sts3x", sts3x}, {} }; MODULE_DEVICE_TABLE(i2c, sht3x_ids); static struct i2c_driver sht3x_i2c_driver = { .driver.name = "sht3x", .probe_new = sht3x_probe, .id_table = sht3x_ids, }; module_i2c_driver(sht3x_i2c_driver); MODULE_AUTHOR("David Frey <david.frey@sensirion.com>"); MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>"); MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver"); MODULE_LICENSE("GPL"); |