1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC3022 4 * temperature + relative humidity sensors 5 * 6 * Copyright (C) 2023 7 * 8 * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH 9 * 10 * Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf 11 */ 12 13 #include <linux/bitfield.h> 14 #include <linux/bitops.h> 15 #include <linux/cleanup.h> 16 #include <linux/crc8.h> 17 #include <linux/delay.h> 18 #include <linux/gpio/consumer.h> 19 #include <linux/i2c.h> 20 #include <linux/init.h> 21 #include <linux/interrupt.h> 22 #include <linux/math64.h> 23 #include <linux/module.h> 24 #include <linux/mutex.h> 25 #include <linux/pm.h> 26 #include <linux/regulator/consumer.h> 27 #include <linux/units.h> 28 29 #include <linux/unaligned.h> 30 31 #include <linux/iio/events.h> 32 #include <linux/iio/iio.h> 33 34 #define HDC3020_S_AUTO_10HZ_MOD0 0x2737 35 #define HDC3020_S_STATUS 0x3041 36 #define HDC3020_HEATER_DISABLE 0x3066 37 #define HDC3020_HEATER_ENABLE 0x306D 38 #define HDC3020_HEATER_CONFIG 0x306E 39 #define HDC3020_EXIT_AUTO 0x3093 40 #define HDC3020_S_T_RH_THRESH_LOW 0x6100 41 #define HDC3020_S_T_RH_THRESH_LOW_CLR 0x610B 42 #define HDC3020_S_T_RH_THRESH_HIGH_CLR 0x6116 43 #define HDC3020_S_T_RH_THRESH_HIGH 0x611D 44 #define HDC3020_R_T_RH_AUTO 0xE000 45 #define HDC3020_R_T_LOW_AUTO 0xE002 46 #define HDC3020_R_T_HIGH_AUTO 0xE003 47 #define HDC3020_R_RH_LOW_AUTO 0xE004 48 #define HDC3020_R_RH_HIGH_AUTO 0xE005 49 #define HDC3020_R_T_RH_THRESH_LOW 0xE102 50 #define HDC3020_R_T_RH_THRESH_LOW_CLR 0xE109 51 #define HDC3020_R_T_RH_THRESH_HIGH_CLR 0xE114 52 #define HDC3020_R_T_RH_THRESH_HIGH 0xE11F 53 #define HDC3020_R_STATUS 0xF32D 54 55 #define HDC3020_THRESH_TEMP_MASK GENMASK(8, 0) 56 #define HDC3020_THRESH_TEMP_TRUNC_SHIFT 7 57 #define HDC3020_THRESH_HUM_MASK GENMASK(15, 9) 58 #define HDC3020_THRESH_HUM_TRUNC_SHIFT 9 59 60 #define HDC3020_STATUS_T_LOW_ALERT BIT(6) 61 #define HDC3020_STATUS_T_HIGH_ALERT BIT(7) 62 #define HDC3020_STATUS_RH_LOW_ALERT BIT(8) 63 #define HDC3020_STATUS_RH_HIGH_ALERT BIT(9) 64 65 #define HDC3020_READ_RETRY_TIMES 10 66 #define HDC3020_BUSY_DELAY_MS 10 67 68 #define HDC3020_CRC8_POLYNOMIAL 0x31 69 70 #define HDC3020_MIN_TEMP_MICRO -39872968 71 #define HDC3020_MAX_TEMP_MICRO 124875639 72 #define HDC3020_MAX_TEMP_HYST_MICRO 164748607 73 #define HDC3020_MAX_HUM_MICRO 99220264 74 75 struct hdc3020_data { 76 struct i2c_client *client; 77 struct gpio_desc *reset_gpio; 78 struct regulator *vdd_supply; 79 /* 80 * Ensure that the sensor configuration (currently only heater is 81 * supported) will not be changed during the process of reading 82 * sensor data (this driver will try HDC3020_READ_RETRY_TIMES times 83 * if the device does not respond). 84 */ 85 struct mutex lock; 86 }; 87 88 static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF}; 89 90 static const struct iio_event_spec hdc3020_t_rh_event[] = { 91 { 92 .type = IIO_EV_TYPE_THRESH, 93 .dir = IIO_EV_DIR_RISING, 94 .mask_separate = BIT(IIO_EV_INFO_VALUE) | 95 BIT(IIO_EV_INFO_HYSTERESIS), 96 }, 97 { 98 .type = IIO_EV_TYPE_THRESH, 99 .dir = IIO_EV_DIR_FALLING, 100 .mask_separate = BIT(IIO_EV_INFO_VALUE) | 101 BIT(IIO_EV_INFO_HYSTERESIS), 102 }, 103 }; 104 105 static const struct iio_chan_spec hdc3020_channels[] = { 106 { 107 .type = IIO_TEMP, 108 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 109 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) | 110 BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET), 111 .event_spec = hdc3020_t_rh_event, 112 .num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event), 113 }, 114 { 115 .type = IIO_HUMIDITYRELATIVE, 116 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 117 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) | 118 BIT(IIO_CHAN_INFO_TROUGH), 119 .event_spec = hdc3020_t_rh_event, 120 .num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event), 121 }, 122 { 123 /* 124 * For setting the internal heater, which can be switched on to 125 * prevent or remove any condensation that may develop when the 126 * ambient environment approaches its dew point temperature. 127 */ 128 .type = IIO_CURRENT, 129 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 130 .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), 131 .output = 1, 132 }, 133 }; 134 135 DECLARE_CRC8_TABLE(hdc3020_crc8_table); 136 137 static int hdc3020_write_bytes(struct hdc3020_data *data, u8 *buf, u8 len) 138 { 139 struct i2c_client *client = data->client; 140 struct i2c_msg msg; 141 int ret, cnt; 142 143 msg.addr = client->addr; 144 msg.flags = 0; 145 msg.buf = buf; 146 msg.len = len; 147 148 /* 149 * During the measurement process, HDC3020 will not return data. 150 * So wait for a while and try again 151 */ 152 for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) { 153 ret = i2c_transfer(client->adapter, &msg, 1); 154 if (ret == 1) 155 return 0; 156 157 mdelay(HDC3020_BUSY_DELAY_MS); 158 } 159 dev_err(&client->dev, "Could not write sensor command\n"); 160 161 return -ETIMEDOUT; 162 } 163 164 static 165 int hdc3020_read_bytes(struct hdc3020_data *data, u16 reg, u8 *buf, int len) 166 { 167 u8 reg_buf[2]; 168 int ret, cnt; 169 struct i2c_client *client = data->client; 170 struct i2c_msg msg[2] = { 171 [0] = { 172 .addr = client->addr, 173 .flags = 0, 174 .buf = reg_buf, 175 .len = 2, 176 }, 177 [1] = { 178 .addr = client->addr, 179 .flags = I2C_M_RD, 180 .buf = buf, 181 .len = len, 182 }, 183 }; 184 185 put_unaligned_be16(reg, reg_buf); 186 /* 187 * During the measurement process, HDC3020 will not return data. 188 * So wait for a while and try again 189 */ 190 for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) { 191 ret = i2c_transfer(client->adapter, msg, 2); 192 if (ret == 2) 193 return 0; 194 195 mdelay(HDC3020_BUSY_DELAY_MS); 196 } 197 dev_err(&client->dev, "Could not read sensor data\n"); 198 199 return -ETIMEDOUT; 200 } 201 202 static int hdc3020_read_be16(struct hdc3020_data *data, u16 reg) 203 { 204 u8 crc, buf[3]; 205 int ret; 206 207 ret = hdc3020_read_bytes(data, reg, buf, 3); 208 if (ret < 0) 209 return ret; 210 211 crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); 212 if (crc != buf[2]) 213 return -EINVAL; 214 215 return get_unaligned_be16(buf); 216 } 217 218 static int hdc3020_exec_cmd(struct hdc3020_data *data, u16 reg) 219 { 220 u8 reg_buf[2]; 221 222 put_unaligned_be16(reg, reg_buf); 223 return hdc3020_write_bytes(data, reg_buf, 2); 224 } 225 226 static int hdc3020_read_measurement(struct hdc3020_data *data, 227 enum iio_chan_type type, int *val) 228 { 229 u8 crc, buf[6]; 230 int ret; 231 232 ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6); 233 if (ret < 0) 234 return ret; 235 236 /* CRC check of the temperature measurement */ 237 crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE); 238 if (crc != buf[2]) 239 return -EINVAL; 240 241 /* CRC check of the relative humidity measurement */ 242 crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE); 243 if (crc != buf[5]) 244 return -EINVAL; 245 246 if (type == IIO_TEMP) 247 *val = get_unaligned_be16(buf); 248 else if (type == IIO_HUMIDITYRELATIVE) 249 *val = get_unaligned_be16(&buf[3]); 250 else 251 return -EINVAL; 252 253 return 0; 254 } 255 256 static int hdc3020_read_raw(struct iio_dev *indio_dev, 257 struct iio_chan_spec const *chan, int *val, 258 int *val2, long mask) 259 { 260 struct hdc3020_data *data = iio_priv(indio_dev); 261 int ret; 262 263 if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE) 264 return -EINVAL; 265 266 switch (mask) { 267 case IIO_CHAN_INFO_RAW: { 268 guard(mutex)(&data->lock); 269 ret = hdc3020_read_measurement(data, chan->type, val); 270 if (ret < 0) 271 return ret; 272 273 return IIO_VAL_INT; 274 } 275 case IIO_CHAN_INFO_PEAK: { 276 guard(mutex)(&data->lock); 277 if (chan->type == IIO_TEMP) 278 ret = hdc3020_read_be16(data, HDC3020_R_T_HIGH_AUTO); 279 else 280 ret = hdc3020_read_be16(data, HDC3020_R_RH_HIGH_AUTO); 281 282 if (ret < 0) 283 return ret; 284 285 *val = ret; 286 return IIO_VAL_INT; 287 } 288 case IIO_CHAN_INFO_TROUGH: { 289 guard(mutex)(&data->lock); 290 if (chan->type == IIO_TEMP) 291 ret = hdc3020_read_be16(data, HDC3020_R_T_LOW_AUTO); 292 else 293 ret = hdc3020_read_be16(data, HDC3020_R_RH_LOW_AUTO); 294 295 if (ret < 0) 296 return ret; 297 298 *val = ret; 299 return IIO_VAL_INT; 300 } 301 case IIO_CHAN_INFO_SCALE: 302 *val2 = 65536; 303 if (chan->type == IIO_TEMP) 304 *val = 175; 305 else 306 *val = 100; 307 return IIO_VAL_FRACTIONAL; 308 309 case IIO_CHAN_INFO_OFFSET: 310 if (chan->type != IIO_TEMP) 311 return -EINVAL; 312 313 *val = -16852; 314 return IIO_VAL_INT; 315 316 default: 317 return -EINVAL; 318 } 319 } 320 321 static int hdc3020_read_available(struct iio_dev *indio_dev, 322 struct iio_chan_spec const *chan, 323 const int **vals, 324 int *type, int *length, long mask) 325 { 326 if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT) 327 return -EINVAL; 328 329 *vals = hdc3020_heater_vals; 330 *type = IIO_VAL_INT; 331 332 return IIO_AVAIL_RANGE; 333 } 334 335 static int hdc3020_update_heater(struct hdc3020_data *data, int val) 336 { 337 u8 buf[5]; 338 int ret; 339 340 if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2]) 341 return -EINVAL; 342 343 if (!val) 344 hdc3020_exec_cmd(data, HDC3020_HEATER_DISABLE); 345 346 put_unaligned_be16(HDC3020_HEATER_CONFIG, buf); 347 put_unaligned_be16(val & GENMASK(13, 0), &buf[2]); 348 buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE); 349 ret = hdc3020_write_bytes(data, buf, 5); 350 if (ret < 0) 351 return ret; 352 353 return hdc3020_exec_cmd(data, HDC3020_HEATER_ENABLE); 354 } 355 356 static int hdc3020_write_raw(struct iio_dev *indio_dev, 357 struct iio_chan_spec const *chan, 358 int val, int val2, long mask) 359 { 360 struct hdc3020_data *data = iio_priv(indio_dev); 361 362 switch (mask) { 363 case IIO_CHAN_INFO_RAW: 364 if (chan->type != IIO_CURRENT) 365 return -EINVAL; 366 367 guard(mutex)(&data->lock); 368 return hdc3020_update_heater(data, val); 369 } 370 371 return -EINVAL; 372 } 373 374 static int hdc3020_thresh_get_temp(u16 thresh) 375 { 376 int temp; 377 378 /* 379 * Get the temperature threshold from 9 LSBs, shift them to get 380 * the truncated temperature threshold representation and 381 * calculate the threshold according to the formula in the 382 * datasheet. Result is degree celsius scaled by 65535. 383 */ 384 temp = FIELD_GET(HDC3020_THRESH_TEMP_MASK, thresh) << 385 HDC3020_THRESH_TEMP_TRUNC_SHIFT; 386 387 return -2949075 + (175 * temp); 388 } 389 390 static int hdc3020_thresh_get_hum(u16 thresh) 391 { 392 int hum; 393 394 /* 395 * Get the humidity threshold from 7 MSBs, shift them to get the 396 * truncated humidity threshold representation and calculate the 397 * threshold according to the formula in the datasheet. Result is 398 * percent scaled by 65535. 399 */ 400 hum = FIELD_GET(HDC3020_THRESH_HUM_MASK, thresh) << 401 HDC3020_THRESH_HUM_TRUNC_SHIFT; 402 403 return hum * 100; 404 } 405 406 static u16 hdc3020_thresh_set_temp(int s_temp, u16 curr_thresh) 407 { 408 u64 temp; 409 u16 thresh; 410 411 /* 412 * Calculate temperature threshold, shift it down to get the 413 * truncated threshold representation in the 9LSBs while keeping 414 * the current humidity threshold in the 7 MSBs. 415 */ 416 temp = (u64)(s_temp + 45000000) * 65535ULL; 417 temp = div_u64(temp, 1000000 * 175) >> HDC3020_THRESH_TEMP_TRUNC_SHIFT; 418 thresh = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, temp); 419 thresh |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, curr_thresh) << 420 HDC3020_THRESH_HUM_TRUNC_SHIFT); 421 422 return thresh; 423 } 424 425 static u16 hdc3020_thresh_set_hum(int s_hum, u16 curr_thresh) 426 { 427 u64 hum; 428 u16 thresh; 429 430 /* 431 * Calculate humidity threshold, shift it down and up to get the 432 * truncated threshold representation in the 7MSBs while keeping 433 * the current temperature threshold in the 9 LSBs. 434 */ 435 hum = (u64)(s_hum) * 65535ULL; 436 hum = div_u64(hum, 1000000 * 100) >> HDC3020_THRESH_HUM_TRUNC_SHIFT; 437 thresh = FIELD_PREP(HDC3020_THRESH_HUM_MASK, hum); 438 thresh |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, curr_thresh); 439 440 return thresh; 441 } 442 443 static 444 int hdc3020_thresh_clr(s64 s_thresh, s64 s_hyst, enum iio_event_direction dir) 445 { 446 s64 s_clr; 447 448 /* 449 * Include directions when calculation the clear value, 450 * since hysteresis is unsigned by definition and the 451 * clear value is an absolute value which is signed. 452 */ 453 if (dir == IIO_EV_DIR_RISING) 454 s_clr = s_thresh - s_hyst; 455 else 456 s_clr = s_thresh + s_hyst; 457 458 /* Divide by 65535 to get units of micro */ 459 return div_s64(s_clr, 65535); 460 } 461 462 static int _hdc3020_write_thresh(struct hdc3020_data *data, u16 reg, u16 val) 463 { 464 u8 buf[5]; 465 466 put_unaligned_be16(reg, buf); 467 put_unaligned_be16(val, buf + 2); 468 buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE); 469 470 return hdc3020_write_bytes(data, buf, 5); 471 } 472 473 static int hdc3020_write_thresh(struct iio_dev *indio_dev, 474 const struct iio_chan_spec *chan, 475 enum iio_event_type type, 476 enum iio_event_direction dir, 477 enum iio_event_info info, 478 int val, int val2) 479 { 480 struct hdc3020_data *data = iio_priv(indio_dev); 481 u16 reg, reg_val, reg_thresh_rd, reg_clr_rd, reg_thresh_wr, reg_clr_wr; 482 s64 s_thresh, s_hyst, s_clr; 483 int s_val, thresh, clr, ret; 484 485 /* Select threshold registers */ 486 if (dir == IIO_EV_DIR_RISING) { 487 reg_thresh_rd = HDC3020_R_T_RH_THRESH_HIGH; 488 reg_thresh_wr = HDC3020_S_T_RH_THRESH_HIGH; 489 reg_clr_rd = HDC3020_R_T_RH_THRESH_HIGH_CLR; 490 reg_clr_wr = HDC3020_S_T_RH_THRESH_HIGH_CLR; 491 } else { 492 reg_thresh_rd = HDC3020_R_T_RH_THRESH_LOW; 493 reg_thresh_wr = HDC3020_S_T_RH_THRESH_LOW; 494 reg_clr_rd = HDC3020_R_T_RH_THRESH_LOW_CLR; 495 reg_clr_wr = HDC3020_S_T_RH_THRESH_LOW_CLR; 496 } 497 498 guard(mutex)(&data->lock); 499 ret = hdc3020_read_be16(data, reg_thresh_rd); 500 if (ret < 0) 501 return ret; 502 503 thresh = ret; 504 ret = hdc3020_read_be16(data, reg_clr_rd); 505 if (ret < 0) 506 return ret; 507 508 clr = ret; 509 /* Scale value to include decimal part into calculations */ 510 s_val = (val < 0) ? (val * 1000000 - val2) : (val * 1000000 + val2); 511 switch (chan->type) { 512 case IIO_TEMP: 513 switch (info) { 514 case IIO_EV_INFO_VALUE: 515 s_val = max(s_val, HDC3020_MIN_TEMP_MICRO); 516 s_val = min(s_val, HDC3020_MAX_TEMP_MICRO); 517 reg = reg_thresh_wr; 518 reg_val = hdc3020_thresh_set_temp(s_val, thresh); 519 ret = _hdc3020_write_thresh(data, reg, reg_val); 520 if (ret < 0) 521 return ret; 522 523 /* Calculate old hysteresis */ 524 s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000; 525 s_clr = (s64)hdc3020_thresh_get_temp(clr) * 1000000; 526 s_hyst = div_s64(abs(s_thresh - s_clr), 65535); 527 /* Set new threshold */ 528 thresh = reg_val; 529 /* Set old hysteresis */ 530 s_val = s_hyst; 531 fallthrough; 532 case IIO_EV_INFO_HYSTERESIS: 533 /* 534 * Function hdc3020_thresh_get_temp returns temperature 535 * in degree celsius scaled by 65535. Scale by 1000000 536 * to be able to subtract scaled hysteresis value. 537 */ 538 s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000; 539 /* 540 * Units of s_val are in micro degree celsius, scale by 541 * 65535 to get same units as s_thresh. 542 */ 543 s_val = min(abs(s_val), HDC3020_MAX_TEMP_HYST_MICRO); 544 s_hyst = (s64)s_val * 65535; 545 s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir); 546 s_clr = max(s_clr, HDC3020_MIN_TEMP_MICRO); 547 s_clr = min(s_clr, HDC3020_MAX_TEMP_MICRO); 548 reg = reg_clr_wr; 549 reg_val = hdc3020_thresh_set_temp(s_clr, clr); 550 break; 551 default: 552 return -EOPNOTSUPP; 553 } 554 break; 555 case IIO_HUMIDITYRELATIVE: 556 s_val = (s_val < 0) ? 0 : min(s_val, HDC3020_MAX_HUM_MICRO); 557 switch (info) { 558 case IIO_EV_INFO_VALUE: 559 reg = reg_thresh_wr; 560 reg_val = hdc3020_thresh_set_hum(s_val, thresh); 561 ret = _hdc3020_write_thresh(data, reg, reg_val); 562 if (ret < 0) 563 return ret; 564 565 /* Calculate old hysteresis */ 566 s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000; 567 s_clr = (s64)hdc3020_thresh_get_hum(clr) * 1000000; 568 s_hyst = div_s64(abs(s_thresh - s_clr), 65535); 569 /* Set new threshold */ 570 thresh = reg_val; 571 /* Try to set old hysteresis */ 572 s_val = min(abs(s_hyst), HDC3020_MAX_HUM_MICRO); 573 fallthrough; 574 case IIO_EV_INFO_HYSTERESIS: 575 /* 576 * Function hdc3020_thresh_get_hum returns relative 577 * humidity in percent scaled by 65535. Scale by 1000000 578 * to be able to subtract scaled hysteresis value. 579 */ 580 s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000; 581 /* 582 * Units of s_val are in micro percent, scale by 65535 583 * to get same units as s_thresh. 584 */ 585 s_hyst = (s64)s_val * 65535; 586 s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir); 587 s_clr = max(s_clr, 0); 588 s_clr = min(s_clr, HDC3020_MAX_HUM_MICRO); 589 reg = reg_clr_wr; 590 reg_val = hdc3020_thresh_set_hum(s_clr, clr); 591 break; 592 default: 593 return -EOPNOTSUPP; 594 } 595 break; 596 default: 597 return -EOPNOTSUPP; 598 } 599 600 return _hdc3020_write_thresh(data, reg, reg_val); 601 } 602 603 static int hdc3020_read_thresh(struct iio_dev *indio_dev, 604 const struct iio_chan_spec *chan, 605 enum iio_event_type type, 606 enum iio_event_direction dir, 607 enum iio_event_info info, 608 int *val, int *val2) 609 { 610 struct hdc3020_data *data = iio_priv(indio_dev); 611 u16 reg_thresh, reg_clr; 612 int thresh, clr, ret; 613 614 /* Select threshold registers */ 615 if (dir == IIO_EV_DIR_RISING) { 616 reg_thresh = HDC3020_R_T_RH_THRESH_HIGH; 617 reg_clr = HDC3020_R_T_RH_THRESH_HIGH_CLR; 618 } else { 619 reg_thresh = HDC3020_R_T_RH_THRESH_LOW; 620 reg_clr = HDC3020_R_T_RH_THRESH_LOW_CLR; 621 } 622 623 guard(mutex)(&data->lock); 624 ret = hdc3020_read_be16(data, reg_thresh); 625 if (ret < 0) 626 return ret; 627 628 switch (chan->type) { 629 case IIO_TEMP: 630 thresh = hdc3020_thresh_get_temp(ret); 631 switch (info) { 632 case IIO_EV_INFO_VALUE: 633 *val = thresh; 634 break; 635 case IIO_EV_INFO_HYSTERESIS: 636 ret = hdc3020_read_be16(data, reg_clr); 637 if (ret < 0) 638 return ret; 639 640 clr = hdc3020_thresh_get_temp(ret); 641 *val = abs(thresh - clr); 642 break; 643 default: 644 return -EOPNOTSUPP; 645 } 646 *val2 = 65535; 647 return IIO_VAL_FRACTIONAL; 648 case IIO_HUMIDITYRELATIVE: 649 thresh = hdc3020_thresh_get_hum(ret); 650 switch (info) { 651 case IIO_EV_INFO_VALUE: 652 *val = thresh; 653 break; 654 case IIO_EV_INFO_HYSTERESIS: 655 ret = hdc3020_read_be16(data, reg_clr); 656 if (ret < 0) 657 return ret; 658 659 clr = hdc3020_thresh_get_hum(ret); 660 *val = abs(thresh - clr); 661 break; 662 default: 663 return -EOPNOTSUPP; 664 } 665 *val2 = 65535; 666 return IIO_VAL_FRACTIONAL; 667 default: 668 return -EOPNOTSUPP; 669 } 670 } 671 672 static irqreturn_t hdc3020_interrupt_handler(int irq, void *private) 673 { 674 struct iio_dev *indio_dev = private; 675 struct hdc3020_data *data; 676 s64 time; 677 int ret; 678 679 data = iio_priv(indio_dev); 680 ret = hdc3020_read_be16(data, HDC3020_R_STATUS); 681 if (ret < 0) 682 return IRQ_HANDLED; 683 684 if (!(ret & (HDC3020_STATUS_T_HIGH_ALERT | HDC3020_STATUS_T_LOW_ALERT | 685 HDC3020_STATUS_RH_HIGH_ALERT | HDC3020_STATUS_RH_LOW_ALERT))) 686 return IRQ_NONE; 687 688 time = iio_get_time_ns(indio_dev); 689 if (ret & HDC3020_STATUS_T_HIGH_ALERT) 690 iio_push_event(indio_dev, 691 IIO_MOD_EVENT_CODE(IIO_TEMP, 0, 692 IIO_NO_MOD, 693 IIO_EV_TYPE_THRESH, 694 IIO_EV_DIR_RISING), 695 time); 696 697 if (ret & HDC3020_STATUS_T_LOW_ALERT) 698 iio_push_event(indio_dev, 699 IIO_MOD_EVENT_CODE(IIO_TEMP, 0, 700 IIO_NO_MOD, 701 IIO_EV_TYPE_THRESH, 702 IIO_EV_DIR_FALLING), 703 time); 704 705 if (ret & HDC3020_STATUS_RH_HIGH_ALERT) 706 iio_push_event(indio_dev, 707 IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0, 708 IIO_NO_MOD, 709 IIO_EV_TYPE_THRESH, 710 IIO_EV_DIR_RISING), 711 time); 712 713 if (ret & HDC3020_STATUS_RH_LOW_ALERT) 714 iio_push_event(indio_dev, 715 IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0, 716 IIO_NO_MOD, 717 IIO_EV_TYPE_THRESH, 718 IIO_EV_DIR_FALLING), 719 time); 720 721 return IRQ_HANDLED; 722 } 723 724 static const struct iio_info hdc3020_info = { 725 .read_raw = hdc3020_read_raw, 726 .write_raw = hdc3020_write_raw, 727 .read_avail = hdc3020_read_available, 728 .read_event_value = hdc3020_read_thresh, 729 .write_event_value = hdc3020_write_thresh, 730 }; 731 732 static int hdc3020_power_off(struct hdc3020_data *data) 733 { 734 hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO); 735 736 if (data->reset_gpio) 737 gpiod_set_value_cansleep(data->reset_gpio, 1); 738 739 return regulator_disable(data->vdd_supply); 740 } 741 742 static int hdc3020_power_on(struct hdc3020_data *data) 743 { 744 int ret; 745 746 ret = regulator_enable(data->vdd_supply); 747 if (ret) 748 return ret; 749 750 fsleep(5000); 751 752 if (data->reset_gpio) { 753 gpiod_set_value_cansleep(data->reset_gpio, 0); 754 fsleep(3000); 755 } 756 757 if (data->client->irq) { 758 /* 759 * The alert output is activated by default upon power up, 760 * hardware reset, and soft reset. Clear the status register. 761 */ 762 ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS); 763 if (ret) { 764 hdc3020_power_off(data); 765 return ret; 766 } 767 } 768 769 ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0); 770 if (ret) 771 hdc3020_power_off(data); 772 773 return ret; 774 } 775 776 static void hdc3020_exit(void *data) 777 { 778 hdc3020_power_off(data); 779 } 780 781 static int hdc3020_probe(struct i2c_client *client) 782 { 783 struct iio_dev *indio_dev; 784 struct hdc3020_data *data; 785 int ret; 786 787 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 788 return -EOPNOTSUPP; 789 790 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 791 if (!indio_dev) 792 return -ENOMEM; 793 794 dev_set_drvdata(&client->dev, indio_dev); 795 796 data = iio_priv(indio_dev); 797 data->client = client; 798 mutex_init(&data->lock); 799 800 crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL); 801 802 indio_dev->name = "hdc3020"; 803 indio_dev->modes = INDIO_DIRECT_MODE; 804 indio_dev->info = &hdc3020_info; 805 indio_dev->channels = hdc3020_channels; 806 indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels); 807 808 data->vdd_supply = devm_regulator_get(&client->dev, "vdd"); 809 if (IS_ERR(data->vdd_supply)) 810 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply), 811 "Unable to get VDD regulator\n"); 812 813 data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", 814 GPIOD_OUT_HIGH); 815 if (IS_ERR(data->reset_gpio)) 816 return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio), 817 "Cannot get reset GPIO\n"); 818 819 ret = hdc3020_power_on(data); 820 if (ret) 821 return dev_err_probe(&client->dev, ret, "Power on failed\n"); 822 823 ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data); 824 if (ret) 825 return ret; 826 827 if (client->irq) { 828 ret = devm_request_threaded_irq(&client->dev, client->irq, 829 NULL, hdc3020_interrupt_handler, 830 IRQF_ONESHOT, "hdc3020", 831 indio_dev); 832 if (ret) 833 return dev_err_probe(&client->dev, ret, 834 "Failed to request IRQ\n"); 835 } 836 837 ret = devm_iio_device_register(&data->client->dev, indio_dev); 838 if (ret) 839 return dev_err_probe(&client->dev, ret, "Failed to add device"); 840 841 return 0; 842 } 843 844 static int hdc3020_suspend(struct device *dev) 845 { 846 struct iio_dev *iio_dev = dev_get_drvdata(dev); 847 struct hdc3020_data *data = iio_priv(iio_dev); 848 849 return hdc3020_power_off(data); 850 } 851 852 static int hdc3020_resume(struct device *dev) 853 { 854 struct iio_dev *iio_dev = dev_get_drvdata(dev); 855 struct hdc3020_data *data = iio_priv(iio_dev); 856 857 return hdc3020_power_on(data); 858 } 859 860 static DEFINE_SIMPLE_DEV_PM_OPS(hdc3020_pm_ops, hdc3020_suspend, hdc3020_resume); 861 862 static const struct i2c_device_id hdc3020_id[] = { 863 { "hdc3020" }, 864 { "hdc3021" }, 865 { "hdc3022" }, 866 { } 867 }; 868 MODULE_DEVICE_TABLE(i2c, hdc3020_id); 869 870 static const struct of_device_id hdc3020_dt_ids[] = { 871 { .compatible = "ti,hdc3020" }, 872 { .compatible = "ti,hdc3021" }, 873 { .compatible = "ti,hdc3022" }, 874 { } 875 }; 876 MODULE_DEVICE_TABLE(of, hdc3020_dt_ids); 877 878 static struct i2c_driver hdc3020_driver = { 879 .driver = { 880 .name = "hdc3020", 881 .pm = pm_sleep_ptr(&hdc3020_pm_ops), 882 .of_match_table = hdc3020_dt_ids, 883 }, 884 .probe = hdc3020_probe, 885 .id_table = hdc3020_id, 886 }; 887 module_i2c_driver(hdc3020_driver); 888 889 MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>"); 890 MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>"); 891 MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver"); 892 MODULE_LICENSE("GPL"); 893