1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Bosch BME680 - Temperature, Pressure, Humidity & Gas Sensor 4 * 5 * Copyright (C) 2017 - 2018 Bosch Sensortec GmbH 6 * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com> 7 * 8 * Datasheet: 9 * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf 10 */ 11 #include <linux/acpi.h> 12 #include <linux/bitfield.h> 13 #include <linux/device.h> 14 #include <linux/module.h> 15 #include <linux/log2.h> 16 #include <linux/regmap.h> 17 #include <linux/iio/iio.h> 18 #include <linux/iio/sysfs.h> 19 20 #include "bme680.h" 21 22 struct bme680_calib { 23 u16 par_t1; 24 s16 par_t2; 25 s8 par_t3; 26 u16 par_p1; 27 s16 par_p2; 28 s8 par_p3; 29 s16 par_p4; 30 s16 par_p5; 31 s8 par_p6; 32 s8 par_p7; 33 s16 par_p8; 34 s16 par_p9; 35 u8 par_p10; 36 u16 par_h1; 37 u16 par_h2; 38 s8 par_h3; 39 s8 par_h4; 40 s8 par_h5; 41 s8 par_h6; 42 s8 par_h7; 43 s8 par_gh1; 44 s16 par_gh2; 45 s8 par_gh3; 46 u8 res_heat_range; 47 s8 res_heat_val; 48 s8 range_sw_err; 49 }; 50 51 struct bme680_data { 52 struct regmap *regmap; 53 struct bme680_calib bme680; 54 u8 oversampling_temp; 55 u8 oversampling_press; 56 u8 oversampling_humid; 57 u16 heater_dur; 58 u16 heater_temp; 59 /* 60 * Carryover value from temperature conversion, used in pressure 61 * and humidity compensation calculations. 62 */ 63 s32 t_fine; 64 }; 65 66 static const struct regmap_range bme680_volatile_ranges[] = { 67 regmap_reg_range(BME680_REG_MEAS_STAT_0, BME680_REG_GAS_R_LSB), 68 regmap_reg_range(BME680_REG_STATUS, BME680_REG_STATUS), 69 regmap_reg_range(BME680_T2_LSB_REG, BME680_GH3_REG), 70 }; 71 72 static const struct regmap_access_table bme680_volatile_table = { 73 .yes_ranges = bme680_volatile_ranges, 74 .n_yes_ranges = ARRAY_SIZE(bme680_volatile_ranges), 75 }; 76 77 const struct regmap_config bme680_regmap_config = { 78 .reg_bits = 8, 79 .val_bits = 8, 80 .max_register = 0xef, 81 .volatile_table = &bme680_volatile_table, 82 .cache_type = REGCACHE_RBTREE, 83 }; 84 EXPORT_SYMBOL_NS(bme680_regmap_config, IIO_BME680); 85 86 static const struct iio_chan_spec bme680_channels[] = { 87 { 88 .type = IIO_TEMP, 89 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 90 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 91 }, 92 { 93 .type = IIO_PRESSURE, 94 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 95 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 96 }, 97 { 98 .type = IIO_HUMIDITYRELATIVE, 99 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 100 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 101 }, 102 { 103 .type = IIO_RESISTANCE, 104 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 105 }, 106 }; 107 108 static int bme680_read_calib(struct bme680_data *data, 109 struct bme680_calib *calib) 110 { 111 struct device *dev = regmap_get_device(data->regmap); 112 unsigned int tmp, tmp_msb, tmp_lsb; 113 int ret; 114 __le16 buf; 115 116 /* Temperature related coefficients */ 117 ret = regmap_bulk_read(data->regmap, BME680_T1_LSB_REG, 118 &buf, sizeof(buf)); 119 if (ret < 0) { 120 dev_err(dev, "failed to read BME680_T1_LSB_REG\n"); 121 return ret; 122 } 123 calib->par_t1 = le16_to_cpu(buf); 124 125 ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG, 126 &buf, sizeof(buf)); 127 if (ret < 0) { 128 dev_err(dev, "failed to read BME680_T2_LSB_REG\n"); 129 return ret; 130 } 131 calib->par_t2 = le16_to_cpu(buf); 132 133 ret = regmap_read(data->regmap, BME680_T3_REG, &tmp); 134 if (ret < 0) { 135 dev_err(dev, "failed to read BME680_T3_REG\n"); 136 return ret; 137 } 138 calib->par_t3 = tmp; 139 140 /* Pressure related coefficients */ 141 ret = regmap_bulk_read(data->regmap, BME680_P1_LSB_REG, 142 &buf, sizeof(buf)); 143 if (ret < 0) { 144 dev_err(dev, "failed to read BME680_P1_LSB_REG\n"); 145 return ret; 146 } 147 calib->par_p1 = le16_to_cpu(buf); 148 149 ret = regmap_bulk_read(data->regmap, BME680_P2_LSB_REG, 150 &buf, sizeof(buf)); 151 if (ret < 0) { 152 dev_err(dev, "failed to read BME680_P2_LSB_REG\n"); 153 return ret; 154 } 155 calib->par_p2 = le16_to_cpu(buf); 156 157 ret = regmap_read(data->regmap, BME680_P3_REG, &tmp); 158 if (ret < 0) { 159 dev_err(dev, "failed to read BME680_P3_REG\n"); 160 return ret; 161 } 162 calib->par_p3 = tmp; 163 164 ret = regmap_bulk_read(data->regmap, BME680_P4_LSB_REG, 165 &buf, sizeof(buf)); 166 if (ret < 0) { 167 dev_err(dev, "failed to read BME680_P4_LSB_REG\n"); 168 return ret; 169 } 170 calib->par_p4 = le16_to_cpu(buf); 171 172 ret = regmap_bulk_read(data->regmap, BME680_P5_LSB_REG, 173 &buf, sizeof(buf)); 174 if (ret < 0) { 175 dev_err(dev, "failed to read BME680_P5_LSB_REG\n"); 176 return ret; 177 } 178 calib->par_p5 = le16_to_cpu(buf); 179 180 ret = regmap_read(data->regmap, BME680_P6_REG, &tmp); 181 if (ret < 0) { 182 dev_err(dev, "failed to read BME680_P6_REG\n"); 183 return ret; 184 } 185 calib->par_p6 = tmp; 186 187 ret = regmap_read(data->regmap, BME680_P7_REG, &tmp); 188 if (ret < 0) { 189 dev_err(dev, "failed to read BME680_P7_REG\n"); 190 return ret; 191 } 192 calib->par_p7 = tmp; 193 194 ret = regmap_bulk_read(data->regmap, BME680_P8_LSB_REG, 195 &buf, sizeof(buf)); 196 if (ret < 0) { 197 dev_err(dev, "failed to read BME680_P8_LSB_REG\n"); 198 return ret; 199 } 200 calib->par_p8 = le16_to_cpu(buf); 201 202 ret = regmap_bulk_read(data->regmap, BME680_P9_LSB_REG, 203 &buf, sizeof(buf)); 204 if (ret < 0) { 205 dev_err(dev, "failed to read BME680_P9_LSB_REG\n"); 206 return ret; 207 } 208 calib->par_p9 = le16_to_cpu(buf); 209 210 ret = regmap_read(data->regmap, BME680_P10_REG, &tmp); 211 if (ret < 0) { 212 dev_err(dev, "failed to read BME680_P10_REG\n"); 213 return ret; 214 } 215 calib->par_p10 = tmp; 216 217 /* Humidity related coefficients */ 218 ret = regmap_read(data->regmap, BME680_H1_MSB_REG, &tmp_msb); 219 if (ret < 0) { 220 dev_err(dev, "failed to read BME680_H1_MSB_REG\n"); 221 return ret; 222 } 223 ret = regmap_read(data->regmap, BME680_H1_LSB_REG, &tmp_lsb); 224 if (ret < 0) { 225 dev_err(dev, "failed to read BME680_H1_LSB_REG\n"); 226 return ret; 227 } 228 calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 229 (tmp_lsb & BME680_BIT_H1_DATA_MASK); 230 231 ret = regmap_read(data->regmap, BME680_H2_MSB_REG, &tmp_msb); 232 if (ret < 0) { 233 dev_err(dev, "failed to read BME680_H2_MSB_REG\n"); 234 return ret; 235 } 236 ret = regmap_read(data->regmap, BME680_H2_LSB_REG, &tmp_lsb); 237 if (ret < 0) { 238 dev_err(dev, "failed to read BME680_H2_LSB_REG\n"); 239 return ret; 240 } 241 calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 242 (tmp_lsb >> BME680_HUM_REG_SHIFT_VAL); 243 244 ret = regmap_read(data->regmap, BME680_H3_REG, &tmp); 245 if (ret < 0) { 246 dev_err(dev, "failed to read BME680_H3_REG\n"); 247 return ret; 248 } 249 calib->par_h3 = tmp; 250 251 ret = regmap_read(data->regmap, BME680_H4_REG, &tmp); 252 if (ret < 0) { 253 dev_err(dev, "failed to read BME680_H4_REG\n"); 254 return ret; 255 } 256 calib->par_h4 = tmp; 257 258 ret = regmap_read(data->regmap, BME680_H5_REG, &tmp); 259 if (ret < 0) { 260 dev_err(dev, "failed to read BME680_H5_REG\n"); 261 return ret; 262 } 263 calib->par_h5 = tmp; 264 265 ret = regmap_read(data->regmap, BME680_H6_REG, &tmp); 266 if (ret < 0) { 267 dev_err(dev, "failed to read BME680_H6_REG\n"); 268 return ret; 269 } 270 calib->par_h6 = tmp; 271 272 ret = regmap_read(data->regmap, BME680_H7_REG, &tmp); 273 if (ret < 0) { 274 dev_err(dev, "failed to read BME680_H7_REG\n"); 275 return ret; 276 } 277 calib->par_h7 = tmp; 278 279 /* Gas heater related coefficients */ 280 ret = regmap_read(data->regmap, BME680_GH1_REG, &tmp); 281 if (ret < 0) { 282 dev_err(dev, "failed to read BME680_GH1_REG\n"); 283 return ret; 284 } 285 calib->par_gh1 = tmp; 286 287 ret = regmap_bulk_read(data->regmap, BME680_GH2_LSB_REG, 288 &buf, sizeof(buf)); 289 if (ret < 0) { 290 dev_err(dev, "failed to read BME680_GH2_LSB_REG\n"); 291 return ret; 292 } 293 calib->par_gh2 = le16_to_cpu(buf); 294 295 ret = regmap_read(data->regmap, BME680_GH3_REG, &tmp); 296 if (ret < 0) { 297 dev_err(dev, "failed to read BME680_GH3_REG\n"); 298 return ret; 299 } 300 calib->par_gh3 = tmp; 301 302 /* Other coefficients */ 303 ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_RANGE, &tmp); 304 if (ret < 0) { 305 dev_err(dev, "failed to read resistance heat range\n"); 306 return ret; 307 } 308 calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK, tmp); 309 310 ret = regmap_read(data->regmap, BME680_REG_RES_HEAT_VAL, &tmp); 311 if (ret < 0) { 312 dev_err(dev, "failed to read resistance heat value\n"); 313 return ret; 314 } 315 calib->res_heat_val = tmp; 316 317 ret = regmap_read(data->regmap, BME680_REG_RANGE_SW_ERR, &tmp); 318 if (ret < 0) { 319 dev_err(dev, "failed to read range software error\n"); 320 return ret; 321 } 322 calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK, tmp); 323 324 return 0; 325 } 326 327 /* 328 * Taken from Bosch BME680 API: 329 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L876 330 * 331 * Returns temperature measurement in DegC, resolutions is 0.01 DegC. Therefore, 332 * output value of "3233" represents 32.33 DegC. 333 */ 334 static s16 bme680_compensate_temp(struct bme680_data *data, 335 s32 adc_temp) 336 { 337 struct bme680_calib *calib = &data->bme680; 338 s64 var1, var2, var3; 339 s16 calc_temp; 340 341 /* If the calibration is invalid, attempt to reload it */ 342 if (!calib->par_t2) 343 bme680_read_calib(data, calib); 344 345 var1 = (adc_temp >> 3) - (calib->par_t1 << 1); 346 var2 = (var1 * calib->par_t2) >> 11; 347 var3 = ((var1 >> 1) * (var1 >> 1)) >> 12; 348 var3 = (var3 * (calib->par_t3 << 4)) >> 14; 349 data->t_fine = var2 + var3; 350 calc_temp = (data->t_fine * 5 + 128) >> 8; 351 352 return calc_temp; 353 } 354 355 /* 356 * Taken from Bosch BME680 API: 357 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L896 358 * 359 * Returns pressure measurement in Pa. Output value of "97356" represents 360 * 97356 Pa = 973.56 hPa. 361 */ 362 static u32 bme680_compensate_press(struct bme680_data *data, 363 u32 adc_press) 364 { 365 struct bme680_calib *calib = &data->bme680; 366 s32 var1, var2, var3, press_comp; 367 368 var1 = (data->t_fine >> 1) - 64000; 369 var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2; 370 var2 = var2 + (var1 * calib->par_p5 << 1); 371 var2 = (var2 >> 2) + (calib->par_p4 << 16); 372 var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) * 373 (calib->par_p3 << 5)) >> 3) + 374 ((calib->par_p2 * var1) >> 1); 375 var1 = var1 >> 18; 376 var1 = ((32768 + var1) * calib->par_p1) >> 15; 377 press_comp = 1048576 - adc_press; 378 press_comp = ((press_comp - (var2 >> 12)) * 3125); 379 380 if (press_comp >= BME680_MAX_OVERFLOW_VAL) 381 press_comp = ((press_comp / (u32)var1) << 1); 382 else 383 press_comp = ((press_comp << 1) / (u32)var1); 384 385 var1 = (calib->par_p9 * (((press_comp >> 3) * 386 (press_comp >> 3)) >> 13)) >> 12; 387 var2 = ((press_comp >> 2) * calib->par_p8) >> 13; 388 var3 = ((press_comp >> 8) * (press_comp >> 8) * 389 (press_comp >> 8) * calib->par_p10) >> 17; 390 391 press_comp += (var1 + var2 + var3 + (calib->par_p7 << 7)) >> 4; 392 393 return press_comp; 394 } 395 396 /* 397 * Taken from Bosch BME680 API: 398 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L937 399 * 400 * Returns humidity measurement in percent, resolution is 0.001 percent. Output 401 * value of "43215" represents 43.215 %rH. 402 */ 403 static u32 bme680_compensate_humid(struct bme680_data *data, 404 u16 adc_humid) 405 { 406 struct bme680_calib *calib = &data->bme680; 407 s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum; 408 409 temp_scaled = (data->t_fine * 5 + 128) >> 8; 410 var1 = (adc_humid - ((s32) ((s32) calib->par_h1 * 16))) - 411 (((temp_scaled * (s32) calib->par_h3) / 100) >> 1); 412 var2 = ((s32) calib->par_h2 * 413 (((temp_scaled * calib->par_h4) / 100) + 414 (((temp_scaled * ((temp_scaled * calib->par_h5) / 100)) 415 >> 6) / 100) + (1 << 14))) >> 10; 416 var3 = var1 * var2; 417 var4 = calib->par_h6 << 7; 418 var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4; 419 var5 = ((var3 >> 14) * (var3 >> 14)) >> 10; 420 var6 = (var4 * var5) >> 1; 421 calc_hum = (((var3 + var6) >> 10) * 1000) >> 12; 422 423 calc_hum = clamp(calc_hum, 0, 100000); /* clamp between 0-100 %rH */ 424 425 return calc_hum; 426 } 427 428 /* 429 * Taken from Bosch BME680 API: 430 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L973 431 * 432 * Returns gas measurement in Ohm. Output value of "82986" represent 82986 ohms. 433 */ 434 static u32 bme680_compensate_gas(struct bme680_data *data, u16 gas_res_adc, 435 u8 gas_range) 436 { 437 struct bme680_calib *calib = &data->bme680; 438 s64 var1; 439 u64 var2; 440 s64 var3; 441 u32 calc_gas_res; 442 443 /* Look up table for the possible gas range values */ 444 const u32 lookupTable[16] = {2147483647u, 2147483647u, 445 2147483647u, 2147483647u, 2147483647u, 446 2126008810u, 2147483647u, 2130303777u, 447 2147483647u, 2147483647u, 2143188679u, 448 2136746228u, 2147483647u, 2126008810u, 449 2147483647u, 2147483647u}; 450 451 var1 = ((1340 + (5 * (s64) calib->range_sw_err)) * 452 ((s64) lookupTable[gas_range])) >> 16; 453 var2 = ((gas_res_adc << 15) - 16777216) + var1; 454 var3 = ((125000 << (15 - gas_range)) * var1) >> 9; 455 var3 += (var2 >> 1); 456 calc_gas_res = div64_s64(var3, (s64) var2); 457 458 return calc_gas_res; 459 } 460 461 /* 462 * Taken from Bosch BME680 API: 463 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1002 464 */ 465 static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp) 466 { 467 struct bme680_calib *calib = &data->bme680; 468 s32 var1, var2, var3, var4, var5, heatr_res_x100; 469 u8 heatr_res; 470 471 if (temp > 400) /* Cap temperature */ 472 temp = 400; 473 474 var1 = (((s32) BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256; 475 var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) * 476 temp * 5) / 100) 477 + 3276800) / 10); 478 var3 = var1 + (var2 / 2); 479 var4 = (var3 / (calib->res_heat_range + 4)); 480 var5 = 131 * calib->res_heat_val + 65536; 481 heatr_res_x100 = ((var4 / var5) - 250) * 34; 482 heatr_res = DIV_ROUND_CLOSEST(heatr_res_x100, 100); 483 484 return heatr_res; 485 } 486 487 /* 488 * Taken from Bosch BME680 API: 489 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1188 490 */ 491 static u8 bme680_calc_heater_dur(u16 dur) 492 { 493 u8 durval, factor = 0; 494 495 if (dur >= 0xfc0) { 496 durval = 0xff; /* Max duration */ 497 } else { 498 while (dur > 0x3F) { 499 dur = dur / 4; 500 factor += 1; 501 } 502 durval = dur + (factor * 64); 503 } 504 505 return durval; 506 } 507 508 static int bme680_set_mode(struct bme680_data *data, bool mode) 509 { 510 struct device *dev = regmap_get_device(data->regmap); 511 int ret; 512 513 if (mode) { 514 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 515 BME680_MODE_MASK, BME680_MODE_FORCED); 516 if (ret < 0) 517 dev_err(dev, "failed to set forced mode\n"); 518 519 } else { 520 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 521 BME680_MODE_MASK, BME680_MODE_SLEEP); 522 if (ret < 0) 523 dev_err(dev, "failed to set sleep mode\n"); 524 525 } 526 527 return ret; 528 } 529 530 static u8 bme680_oversampling_to_reg(u8 val) 531 { 532 return ilog2(val) + 1; 533 } 534 535 static int bme680_chip_config(struct bme680_data *data) 536 { 537 struct device *dev = regmap_get_device(data->regmap); 538 int ret; 539 u8 osrs; 540 541 osrs = FIELD_PREP( 542 BME680_OSRS_HUMIDITY_MASK, 543 bme680_oversampling_to_reg(data->oversampling_humid)); 544 /* 545 * Highly recommended to set oversampling of humidity before 546 * temperature/pressure oversampling. 547 */ 548 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_HUMIDITY, 549 BME680_OSRS_HUMIDITY_MASK, osrs); 550 if (ret < 0) { 551 dev_err(dev, "failed to write ctrl_hum register\n"); 552 return ret; 553 } 554 555 /* IIR filter settings */ 556 ret = regmap_update_bits(data->regmap, BME680_REG_CONFIG, 557 BME680_FILTER_MASK, 558 BME680_FILTER_COEFF_VAL); 559 if (ret < 0) { 560 dev_err(dev, "failed to write config register\n"); 561 return ret; 562 } 563 564 osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK, 565 bme680_oversampling_to_reg(data->oversampling_temp)) | 566 FIELD_PREP(BME680_OSRS_PRESS_MASK, 567 bme680_oversampling_to_reg(data->oversampling_press)); 568 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 569 BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK, 570 osrs); 571 if (ret < 0) 572 dev_err(dev, "failed to write ctrl_meas register\n"); 573 574 return ret; 575 } 576 577 static int bme680_gas_config(struct bme680_data *data) 578 { 579 struct device *dev = regmap_get_device(data->regmap); 580 int ret; 581 u8 heatr_res, heatr_dur; 582 583 heatr_res = bme680_calc_heater_res(data, data->heater_temp); 584 585 /* set target heater temperature */ 586 ret = regmap_write(data->regmap, BME680_REG_RES_HEAT_0, heatr_res); 587 if (ret < 0) { 588 dev_err(dev, "failed to write res_heat_0 register\n"); 589 return ret; 590 } 591 592 heatr_dur = bme680_calc_heater_dur(data->heater_dur); 593 594 /* set target heating duration */ 595 ret = regmap_write(data->regmap, BME680_REG_GAS_WAIT_0, heatr_dur); 596 if (ret < 0) { 597 dev_err(dev, "failed to write gas_wait_0 register\n"); 598 return ret; 599 } 600 601 /* Enable the gas sensor and select heater profile set-point 0 */ 602 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1, 603 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK, 604 FIELD_PREP(BME680_RUN_GAS_MASK, 1) | 605 FIELD_PREP(BME680_NB_CONV_MASK, 0)); 606 if (ret < 0) 607 dev_err(dev, "failed to write ctrl_gas_1 register\n"); 608 609 return ret; 610 } 611 612 static int bme680_read_temp(struct bme680_data *data, int *val) 613 { 614 struct device *dev = regmap_get_device(data->regmap); 615 int ret; 616 __be32 tmp = 0; 617 s32 adc_temp; 618 s16 comp_temp; 619 620 /* set forced mode to trigger measurement */ 621 ret = bme680_set_mode(data, true); 622 if (ret < 0) 623 return ret; 624 625 ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB, 626 &tmp, 3); 627 if (ret < 0) { 628 dev_err(dev, "failed to read temperature\n"); 629 return ret; 630 } 631 632 adc_temp = be32_to_cpu(tmp) >> 12; 633 if (adc_temp == BME680_MEAS_SKIPPED) { 634 /* reading was skipped */ 635 dev_err(dev, "reading temperature skipped\n"); 636 return -EINVAL; 637 } 638 comp_temp = bme680_compensate_temp(data, adc_temp); 639 /* 640 * val might be NULL if we're called by the read_press/read_humid 641 * routine which is called to get t_fine value used in 642 * compensate_press/compensate_humid to get compensated 643 * pressure/humidity readings. 644 */ 645 if (val) { 646 *val = comp_temp * 10; /* Centidegrees to millidegrees */ 647 return IIO_VAL_INT; 648 } 649 650 return ret; 651 } 652 653 static int bme680_read_press(struct bme680_data *data, 654 int *val, int *val2) 655 { 656 struct device *dev = regmap_get_device(data->regmap); 657 int ret; 658 __be32 tmp = 0; 659 s32 adc_press; 660 661 /* Read and compensate temperature to get a reading of t_fine */ 662 ret = bme680_read_temp(data, NULL); 663 if (ret < 0) 664 return ret; 665 666 ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB, 667 &tmp, 3); 668 if (ret < 0) { 669 dev_err(dev, "failed to read pressure\n"); 670 return ret; 671 } 672 673 adc_press = be32_to_cpu(tmp) >> 12; 674 if (adc_press == BME680_MEAS_SKIPPED) { 675 /* reading was skipped */ 676 dev_err(dev, "reading pressure skipped\n"); 677 return -EINVAL; 678 } 679 680 *val = bme680_compensate_press(data, adc_press); 681 *val2 = 100; 682 return IIO_VAL_FRACTIONAL; 683 } 684 685 static int bme680_read_humid(struct bme680_data *data, 686 int *val, int *val2) 687 { 688 struct device *dev = regmap_get_device(data->regmap); 689 int ret; 690 __be16 tmp = 0; 691 s32 adc_humidity; 692 u32 comp_humidity; 693 694 /* Read and compensate temperature to get a reading of t_fine */ 695 ret = bme680_read_temp(data, NULL); 696 if (ret < 0) 697 return ret; 698 699 ret = regmap_bulk_read(data->regmap, BM6880_REG_HUMIDITY_MSB, 700 &tmp, sizeof(tmp)); 701 if (ret < 0) { 702 dev_err(dev, "failed to read humidity\n"); 703 return ret; 704 } 705 706 adc_humidity = be16_to_cpu(tmp); 707 if (adc_humidity == BME680_MEAS_SKIPPED) { 708 /* reading was skipped */ 709 dev_err(dev, "reading humidity skipped\n"); 710 return -EINVAL; 711 } 712 comp_humidity = bme680_compensate_humid(data, adc_humidity); 713 714 *val = comp_humidity; 715 *val2 = 1000; 716 return IIO_VAL_FRACTIONAL; 717 } 718 719 static int bme680_read_gas(struct bme680_data *data, 720 int *val) 721 { 722 struct device *dev = regmap_get_device(data->regmap); 723 int ret; 724 __be16 tmp = 0; 725 unsigned int check; 726 u16 adc_gas_res; 727 u8 gas_range; 728 729 /* Set heater settings */ 730 ret = bme680_gas_config(data); 731 if (ret < 0) { 732 dev_err(dev, "failed to set gas config\n"); 733 return ret; 734 } 735 736 /* set forced mode to trigger measurement */ 737 ret = bme680_set_mode(data, true); 738 if (ret < 0) 739 return ret; 740 741 ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &check); 742 if (check & BME680_GAS_MEAS_BIT) { 743 dev_err(dev, "gas measurement incomplete\n"); 744 return -EBUSY; 745 } 746 747 ret = regmap_read(data->regmap, BME680_REG_GAS_R_LSB, &check); 748 if (ret < 0) { 749 dev_err(dev, "failed to read gas_r_lsb register\n"); 750 return ret; 751 } 752 753 /* 754 * occurs if either the gas heating duration was insuffient 755 * to reach the target heater temperature or the target 756 * heater temperature was too high for the heater sink to 757 * reach. 758 */ 759 if ((check & BME680_GAS_STAB_BIT) == 0) { 760 dev_err(dev, "heater failed to reach the target temperature\n"); 761 return -EINVAL; 762 } 763 764 ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB, 765 &tmp, sizeof(tmp)); 766 if (ret < 0) { 767 dev_err(dev, "failed to read gas resistance\n"); 768 return ret; 769 } 770 771 gas_range = check & BME680_GAS_RANGE_MASK; 772 adc_gas_res = be16_to_cpu(tmp) >> BME680_ADC_GAS_RES_SHIFT; 773 774 *val = bme680_compensate_gas(data, adc_gas_res, gas_range); 775 return IIO_VAL_INT; 776 } 777 778 static int bme680_read_raw(struct iio_dev *indio_dev, 779 struct iio_chan_spec const *chan, 780 int *val, int *val2, long mask) 781 { 782 struct bme680_data *data = iio_priv(indio_dev); 783 784 switch (mask) { 785 case IIO_CHAN_INFO_PROCESSED: 786 switch (chan->type) { 787 case IIO_TEMP: 788 return bme680_read_temp(data, val); 789 case IIO_PRESSURE: 790 return bme680_read_press(data, val, val2); 791 case IIO_HUMIDITYRELATIVE: 792 return bme680_read_humid(data, val, val2); 793 case IIO_RESISTANCE: 794 return bme680_read_gas(data, val); 795 default: 796 return -EINVAL; 797 } 798 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 799 switch (chan->type) { 800 case IIO_TEMP: 801 *val = data->oversampling_temp; 802 return IIO_VAL_INT; 803 case IIO_PRESSURE: 804 *val = data->oversampling_press; 805 return IIO_VAL_INT; 806 case IIO_HUMIDITYRELATIVE: 807 *val = data->oversampling_humid; 808 return IIO_VAL_INT; 809 default: 810 return -EINVAL; 811 } 812 default: 813 return -EINVAL; 814 } 815 } 816 817 static bool bme680_is_valid_oversampling(int rate) 818 { 819 return (rate > 0 && rate <= 16 && is_power_of_2(rate)); 820 } 821 822 static int bme680_write_raw(struct iio_dev *indio_dev, 823 struct iio_chan_spec const *chan, 824 int val, int val2, long mask) 825 { 826 struct bme680_data *data = iio_priv(indio_dev); 827 828 if (val2 != 0) 829 return -EINVAL; 830 831 switch (mask) { 832 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 833 { 834 if (!bme680_is_valid_oversampling(val)) 835 return -EINVAL; 836 837 switch (chan->type) { 838 case IIO_TEMP: 839 data->oversampling_temp = val; 840 break; 841 case IIO_PRESSURE: 842 data->oversampling_press = val; 843 break; 844 case IIO_HUMIDITYRELATIVE: 845 data->oversampling_humid = val; 846 break; 847 default: 848 return -EINVAL; 849 } 850 851 return bme680_chip_config(data); 852 } 853 default: 854 return -EINVAL; 855 } 856 } 857 858 static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16"; 859 860 static IIO_CONST_ATTR(oversampling_ratio_available, 861 bme680_oversampling_ratio_show); 862 863 static struct attribute *bme680_attributes[] = { 864 &iio_const_attr_oversampling_ratio_available.dev_attr.attr, 865 NULL, 866 }; 867 868 static const struct attribute_group bme680_attribute_group = { 869 .attrs = bme680_attributes, 870 }; 871 872 static const struct iio_info bme680_info = { 873 .read_raw = &bme680_read_raw, 874 .write_raw = &bme680_write_raw, 875 .attrs = &bme680_attribute_group, 876 }; 877 878 static const char *bme680_match_acpi_device(struct device *dev) 879 { 880 const struct acpi_device_id *id; 881 882 id = acpi_match_device(dev->driver->acpi_match_table, dev); 883 if (!id) 884 return NULL; 885 886 return dev_name(dev); 887 } 888 889 int bme680_core_probe(struct device *dev, struct regmap *regmap, 890 const char *name) 891 { 892 struct iio_dev *indio_dev; 893 struct bme680_data *data; 894 unsigned int val; 895 int ret; 896 897 ret = regmap_write(regmap, BME680_REG_SOFT_RESET, 898 BME680_CMD_SOFTRESET); 899 if (ret < 0) { 900 dev_err(dev, "Failed to reset chip\n"); 901 return ret; 902 } 903 904 ret = regmap_read(regmap, BME680_REG_CHIP_ID, &val); 905 if (ret < 0) { 906 dev_err(dev, "Error reading chip ID\n"); 907 return ret; 908 } 909 910 if (val != BME680_CHIP_ID_VAL) { 911 dev_err(dev, "Wrong chip ID, got %x expected %x\n", 912 val, BME680_CHIP_ID_VAL); 913 return -ENODEV; 914 } 915 916 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 917 if (!indio_dev) 918 return -ENOMEM; 919 920 if (!name && ACPI_HANDLE(dev)) 921 name = bme680_match_acpi_device(dev); 922 923 data = iio_priv(indio_dev); 924 dev_set_drvdata(dev, indio_dev); 925 data->regmap = regmap; 926 indio_dev->name = name; 927 indio_dev->channels = bme680_channels; 928 indio_dev->num_channels = ARRAY_SIZE(bme680_channels); 929 indio_dev->info = &bme680_info; 930 indio_dev->modes = INDIO_DIRECT_MODE; 931 932 /* default values for the sensor */ 933 data->oversampling_humid = 2; /* 2X oversampling rate */ 934 data->oversampling_press = 4; /* 4X oversampling rate */ 935 data->oversampling_temp = 8; /* 8X oversampling rate */ 936 data->heater_temp = 320; /* degree Celsius */ 937 data->heater_dur = 150; /* milliseconds */ 938 939 ret = bme680_chip_config(data); 940 if (ret < 0) { 941 dev_err(dev, "failed to set chip_config data\n"); 942 return ret; 943 } 944 945 ret = bme680_gas_config(data); 946 if (ret < 0) { 947 dev_err(dev, "failed to set gas config data\n"); 948 return ret; 949 } 950 951 ret = bme680_read_calib(data, &data->bme680); 952 if (ret < 0) { 953 dev_err(dev, 954 "failed to read calibration coefficients at probe\n"); 955 return ret; 956 } 957 958 return devm_iio_device_register(dev, indio_dev); 959 } 960 EXPORT_SYMBOL_NS_GPL(bme680_core_probe, IIO_BME680); 961 962 MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>"); 963 MODULE_DESCRIPTION("Bosch BME680 Driver"); 964 MODULE_LICENSE("GPL v2"); 965