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/bitfield.h> 12 #include <linux/cleanup.h> 13 #include <linux/delay.h> 14 #include <linux/device.h> 15 #include <linux/log2.h> 16 #include <linux/module.h> 17 #include <linux/regmap.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 22 #include <asm/unaligned.h> 23 24 #include "bme680.h" 25 26 /* 1st set of calibration data */ 27 enum { 28 /* Temperature calib indexes */ 29 T2_LSB = 0, 30 T3 = 2, 31 /* Pressure calib indexes */ 32 P1_LSB = 4, 33 P2_LSB = 6, 34 P3 = 8, 35 P4_LSB = 10, 36 P5_LSB = 12, 37 P7 = 14, 38 P6 = 15, 39 P8_LSB = 18, 40 P9_LSB = 20, 41 P10 = 22, 42 }; 43 44 /* 2nd set of calibration data */ 45 enum { 46 /* Humidity calib indexes */ 47 H2_MSB = 0, 48 H1_LSB = 1, 49 H3 = 3, 50 H4 = 4, 51 H5 = 5, 52 H6 = 6, 53 H7 = 7, 54 /* Stray T1 calib index */ 55 T1_LSB = 8, 56 /* Gas heater calib indexes */ 57 GH2_LSB = 10, 58 GH1 = 12, 59 GH3 = 13, 60 }; 61 62 /* 3rd set of calibration data */ 63 enum { 64 RES_HEAT_VAL = 0, 65 RES_HEAT_RANGE = 2, 66 RANGE_SW_ERR = 4, 67 }; 68 69 struct bme680_calib { 70 u16 par_t1; 71 s16 par_t2; 72 s8 par_t3; 73 u16 par_p1; 74 s16 par_p2; 75 s8 par_p3; 76 s16 par_p4; 77 s16 par_p5; 78 s8 par_p6; 79 s8 par_p7; 80 s16 par_p8; 81 s16 par_p9; 82 u8 par_p10; 83 u16 par_h1; 84 u16 par_h2; 85 s8 par_h3; 86 s8 par_h4; 87 s8 par_h5; 88 u8 par_h6; 89 s8 par_h7; 90 s8 par_gh1; 91 s16 par_gh2; 92 s8 par_gh3; 93 u8 res_heat_range; 94 s8 res_heat_val; 95 s8 range_sw_err; 96 }; 97 98 struct bme680_data { 99 struct regmap *regmap; 100 struct bme680_calib bme680; 101 struct mutex lock; /* Protect multiple serial R/W ops to device. */ 102 u8 oversampling_temp; 103 u8 oversampling_press; 104 u8 oversampling_humid; 105 u16 heater_dur; 106 u16 heater_temp; 107 108 union { 109 u8 buf[3]; 110 unsigned int check; 111 __be16 be16; 112 u8 bme680_cal_buf_1[BME680_CALIB_RANGE_1_LEN]; 113 u8 bme680_cal_buf_2[BME680_CALIB_RANGE_2_LEN]; 114 u8 bme680_cal_buf_3[BME680_CALIB_RANGE_3_LEN]; 115 }; 116 }; 117 118 static const struct regmap_range bme680_volatile_ranges[] = { 119 regmap_reg_range(BME680_REG_MEAS_STAT_0, BME680_REG_GAS_R_LSB), 120 regmap_reg_range(BME680_REG_STATUS, BME680_REG_STATUS), 121 regmap_reg_range(BME680_T2_LSB_REG, BME680_GH3_REG), 122 }; 123 124 static const struct regmap_access_table bme680_volatile_table = { 125 .yes_ranges = bme680_volatile_ranges, 126 .n_yes_ranges = ARRAY_SIZE(bme680_volatile_ranges), 127 }; 128 129 const struct regmap_config bme680_regmap_config = { 130 .reg_bits = 8, 131 .val_bits = 8, 132 .max_register = 0xef, 133 .volatile_table = &bme680_volatile_table, 134 .cache_type = REGCACHE_RBTREE, 135 }; 136 EXPORT_SYMBOL_NS(bme680_regmap_config, IIO_BME680); 137 138 static const struct iio_chan_spec bme680_channels[] = { 139 { 140 .type = IIO_TEMP, 141 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 142 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 143 }, 144 { 145 .type = IIO_PRESSURE, 146 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 147 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 148 }, 149 { 150 .type = IIO_HUMIDITYRELATIVE, 151 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 152 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 153 }, 154 { 155 .type = IIO_RESISTANCE, 156 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 157 }, 158 }; 159 160 static int bme680_read_calib(struct bme680_data *data, 161 struct bme680_calib *calib) 162 { 163 struct device *dev = regmap_get_device(data->regmap); 164 unsigned int tmp_msb, tmp_lsb; 165 int ret; 166 167 ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG, 168 data->bme680_cal_buf_1, 169 sizeof(data->bme680_cal_buf_1)); 170 if (ret < 0) { 171 dev_err(dev, "failed to read 1st set of calib data;\n"); 172 return ret; 173 } 174 175 calib->par_t2 = get_unaligned_le16(&data->bme680_cal_buf_1[T2_LSB]); 176 calib->par_t3 = data->bme680_cal_buf_1[T3]; 177 calib->par_p1 = get_unaligned_le16(&data->bme680_cal_buf_1[P1_LSB]); 178 calib->par_p2 = get_unaligned_le16(&data->bme680_cal_buf_1[P2_LSB]); 179 calib->par_p3 = data->bme680_cal_buf_1[P3]; 180 calib->par_p4 = get_unaligned_le16(&data->bme680_cal_buf_1[P4_LSB]); 181 calib->par_p5 = get_unaligned_le16(&data->bme680_cal_buf_1[P5_LSB]); 182 calib->par_p7 = data->bme680_cal_buf_1[P7]; 183 calib->par_p6 = data->bme680_cal_buf_1[P6]; 184 calib->par_p8 = get_unaligned_le16(&data->bme680_cal_buf_1[P8_LSB]); 185 calib->par_p9 = get_unaligned_le16(&data->bme680_cal_buf_1[P9_LSB]); 186 calib->par_p10 = data->bme680_cal_buf_1[P10]; 187 188 ret = regmap_bulk_read(data->regmap, BME680_H2_MSB_REG, 189 data->bme680_cal_buf_2, 190 sizeof(data->bme680_cal_buf_2)); 191 if (ret < 0) { 192 dev_err(dev, "failed to read 2nd set of calib data;\n"); 193 return ret; 194 } 195 196 tmp_lsb = data->bme680_cal_buf_2[H1_LSB]; 197 tmp_msb = data->bme680_cal_buf_2[H1_LSB + 1]; 198 calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 199 (tmp_lsb & BME680_BIT_H1_DATA_MASK); 200 201 tmp_msb = data->bme680_cal_buf_2[H2_MSB]; 202 tmp_lsb = data->bme680_cal_buf_2[H2_MSB + 1]; 203 calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 204 (tmp_lsb >> BME680_HUM_REG_SHIFT_VAL); 205 206 calib->par_h3 = data->bme680_cal_buf_2[H3]; 207 calib->par_h4 = data->bme680_cal_buf_2[H4]; 208 calib->par_h5 = data->bme680_cal_buf_2[H5]; 209 calib->par_h6 = data->bme680_cal_buf_2[H6]; 210 calib->par_h7 = data->bme680_cal_buf_2[H7]; 211 calib->par_t1 = get_unaligned_le16(&data->bme680_cal_buf_2[T1_LSB]); 212 calib->par_gh2 = get_unaligned_le16(&data->bme680_cal_buf_2[GH2_LSB]); 213 calib->par_gh1 = data->bme680_cal_buf_2[GH1]; 214 calib->par_gh3 = data->bme680_cal_buf_2[GH3]; 215 216 ret = regmap_bulk_read(data->regmap, BME680_REG_RES_HEAT_VAL, 217 data->bme680_cal_buf_3, 218 sizeof(data->bme680_cal_buf_3)); 219 if (ret < 0) { 220 dev_err(dev, "failed to read 3rd set of calib data;\n"); 221 return ret; 222 } 223 224 calib->res_heat_val = data->bme680_cal_buf_3[RES_HEAT_VAL]; 225 226 calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK, 227 data->bme680_cal_buf_3[RES_HEAT_RANGE]); 228 229 calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK, 230 data->bme680_cal_buf_3[RANGE_SW_ERR]); 231 232 return 0; 233 } 234 235 static int bme680_read_temp_adc(struct bme680_data *data, u32 *adc_temp) 236 { 237 struct device *dev = regmap_get_device(data->regmap); 238 u32 value_temp; 239 int ret; 240 241 ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB, 242 data->buf, BME680_TEMP_NUM_BYTES); 243 if (ret < 0) { 244 dev_err(dev, "failed to read temperature\n"); 245 return ret; 246 } 247 248 value_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, 249 get_unaligned_be24(data->buf)); 250 if (value_temp == BME680_MEAS_SKIPPED) { 251 /* reading was skipped */ 252 dev_err(dev, "reading temperature skipped\n"); 253 return -EINVAL; 254 } 255 *adc_temp = value_temp; 256 257 return 0; 258 } 259 260 /* 261 * Taken from Bosch BME680 API: 262 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L876 263 * 264 * Returns temperature measurement in DegC, resolutions is 0.01 DegC. Therefore, 265 * output value of "3233" represents 32.33 DegC. 266 */ 267 static s32 bme680_calc_t_fine(struct bme680_data *data, u32 adc_temp) 268 { 269 struct bme680_calib *calib = &data->bme680; 270 s64 var1, var2, var3; 271 272 /* If the calibration is invalid, attempt to reload it */ 273 if (!calib->par_t2) 274 bme680_read_calib(data, calib); 275 276 var1 = ((s32)adc_temp >> 3) - ((s32)calib->par_t1 << 1); 277 var2 = (var1 * calib->par_t2) >> 11; 278 var3 = ((var1 >> 1) * (var1 >> 1)) >> 12; 279 var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14; 280 return var2 + var3; /* t_fine = var2 + var3 */ 281 } 282 283 static int bme680_get_t_fine(struct bme680_data *data, s32 *t_fine) 284 { 285 u32 adc_temp; 286 int ret; 287 288 ret = bme680_read_temp_adc(data, &adc_temp); 289 if (ret) 290 return ret; 291 292 *t_fine = bme680_calc_t_fine(data, adc_temp); 293 294 return 0; 295 } 296 297 static s16 bme680_compensate_temp(struct bme680_data *data, 298 u32 adc_temp) 299 { 300 return (bme680_calc_t_fine(data, adc_temp) * 5 + 128) / 256; 301 } 302 303 static int bme680_read_press_adc(struct bme680_data *data, u32 *adc_press) 304 { 305 struct device *dev = regmap_get_device(data->regmap); 306 u32 value_press; 307 int ret; 308 309 ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB, 310 data->buf, BME680_PRESS_NUM_BYTES); 311 if (ret < 0) { 312 dev_err(dev, "failed to read pressure\n"); 313 return ret; 314 } 315 316 value_press = FIELD_GET(BME680_MEAS_TRIM_MASK, 317 get_unaligned_be24(data->buf)); 318 if (value_press == BME680_MEAS_SKIPPED) { 319 /* reading was skipped */ 320 dev_err(dev, "reading pressure skipped\n"); 321 return -EINVAL; 322 } 323 *adc_press = value_press; 324 325 return 0; 326 } 327 328 /* 329 * Taken from Bosch BME680 API: 330 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L896 331 * 332 * Returns pressure measurement in Pa. Output value of "97356" represents 333 * 97356 Pa = 973.56 hPa. 334 */ 335 static u32 bme680_compensate_press(struct bme680_data *data, 336 u32 adc_press, s32 t_fine) 337 { 338 struct bme680_calib *calib = &data->bme680; 339 s32 var1, var2, var3, press_comp; 340 341 var1 = (t_fine >> 1) - 64000; 342 var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2; 343 var2 = var2 + (var1 * calib->par_p5 << 1); 344 var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16); 345 var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) * 346 ((s32)calib->par_p3 << 5)) >> 3) + 347 ((calib->par_p2 * var1) >> 1); 348 var1 = var1 >> 18; 349 var1 = ((32768 + var1) * calib->par_p1) >> 15; 350 press_comp = 1048576 - adc_press; 351 press_comp = ((press_comp - (var2 >> 12)) * 3125); 352 353 if (press_comp >= BME680_MAX_OVERFLOW_VAL) 354 press_comp = ((press_comp / (u32)var1) << 1); 355 else 356 press_comp = ((press_comp << 1) / (u32)var1); 357 358 var1 = (calib->par_p9 * (((press_comp >> 3) * 359 (press_comp >> 3)) >> 13)) >> 12; 360 var2 = ((press_comp >> 2) * calib->par_p8) >> 13; 361 var3 = ((press_comp >> 8) * (press_comp >> 8) * 362 (press_comp >> 8) * calib->par_p10) >> 17; 363 364 press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4; 365 366 return press_comp; 367 } 368 369 static int bme680_read_humid_adc(struct bme680_data *data, u32 *adc_humidity) 370 { 371 struct device *dev = regmap_get_device(data->regmap); 372 u32 value_humidity; 373 int ret; 374 375 ret = regmap_bulk_read(data->regmap, BME680_REG_HUMIDITY_MSB, 376 &data->be16, BME680_HUMID_NUM_BYTES); 377 if (ret < 0) { 378 dev_err(dev, "failed to read humidity\n"); 379 return ret; 380 } 381 382 value_humidity = be16_to_cpu(data->be16); 383 if (value_humidity == BME680_MEAS_SKIPPED) { 384 /* reading was skipped */ 385 dev_err(dev, "reading humidity skipped\n"); 386 return -EINVAL; 387 } 388 *adc_humidity = value_humidity; 389 390 return 0; 391 } 392 393 /* 394 * Taken from Bosch BME680 API: 395 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L937 396 * 397 * Returns humidity measurement in percent, resolution is 0.001 percent. Output 398 * value of "43215" represents 43.215 %rH. 399 */ 400 static u32 bme680_compensate_humid(struct bme680_data *data, 401 u16 adc_humid, s32 t_fine) 402 { 403 struct bme680_calib *calib = &data->bme680; 404 s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum; 405 406 temp_scaled = (t_fine * 5 + 128) >> 8; 407 var1 = (adc_humid - (((s32)calib->par_h1 * 16))) - 408 (((temp_scaled * calib->par_h3) / 100) >> 1); 409 var2 = (calib->par_h2 * 410 (((temp_scaled * calib->par_h4) / 100) + 411 (((temp_scaled * ((temp_scaled * calib->par_h5) / 100)) 412 >> 6) / 100) + (1 << 14))) >> 10; 413 var3 = var1 * var2; 414 var4 = (s32)calib->par_h6 << 7; 415 var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4; 416 var5 = ((var3 >> 14) * (var3 >> 14)) >> 10; 417 var6 = (var4 * var5) >> 1; 418 calc_hum = (((var3 + var6) >> 10) * 1000) >> 12; 419 420 calc_hum = clamp(calc_hum, 0, 100000); /* clamp between 0-100 %rH */ 421 422 return calc_hum; 423 } 424 425 /* 426 * Taken from Bosch BME680 API: 427 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L973 428 * 429 * Returns gas measurement in Ohm. Output value of "82986" represent 82986 ohms. 430 */ 431 static u32 bme680_compensate_gas(struct bme680_data *data, u16 gas_res_adc, 432 u8 gas_range) 433 { 434 struct bme680_calib *calib = &data->bme680; 435 s64 var1; 436 u64 var2; 437 s64 var3; 438 u32 calc_gas_res; 439 440 /* Look up table for the possible gas range values */ 441 static const u32 lookupTable[16] = {2147483647u, 2147483647u, 442 2147483647u, 2147483647u, 2147483647u, 443 2126008810u, 2147483647u, 2130303777u, 444 2147483647u, 2147483647u, 2143188679u, 445 2136746228u, 2147483647u, 2126008810u, 446 2147483647u, 2147483647u}; 447 448 var1 = ((1340 + (5 * (s64) calib->range_sw_err)) * 449 ((s64) lookupTable[gas_range])) >> 16; 450 var2 = ((gas_res_adc << 15) - 16777216) + var1; 451 var3 = ((125000 << (15 - gas_range)) * var1) >> 9; 452 var3 += (var2 >> 1); 453 calc_gas_res = div64_s64(var3, (s64) var2); 454 455 return calc_gas_res; 456 } 457 458 /* 459 * Taken from Bosch BME680 API: 460 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1002 461 */ 462 static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp) 463 { 464 struct bme680_calib *calib = &data->bme680; 465 s32 var1, var2, var3, var4, var5, heatr_res_x100; 466 u8 heatr_res; 467 468 if (temp > 400) /* Cap temperature */ 469 temp = 400; 470 471 var1 = (((s32) BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256; 472 var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) * 473 temp * 5) / 100) 474 + 3276800) / 10); 475 var3 = var1 + (var2 / 2); 476 var4 = (var3 / (calib->res_heat_range + 4)); 477 var5 = 131 * calib->res_heat_val + 65536; 478 heatr_res_x100 = ((var4 / var5) - 250) * 34; 479 heatr_res = DIV_ROUND_CLOSEST(heatr_res_x100, 100); 480 481 return heatr_res; 482 } 483 484 /* 485 * Taken from Bosch BME680 API: 486 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1188 487 */ 488 static u8 bme680_calc_heater_dur(u16 dur) 489 { 490 u8 durval, factor = 0; 491 492 if (dur >= 0xfc0) { 493 durval = 0xff; /* Max duration */ 494 } else { 495 while (dur > 0x3F) { 496 dur = dur / 4; 497 factor += 1; 498 } 499 durval = dur + (factor * 64); 500 } 501 502 return durval; 503 } 504 505 static int bme680_set_mode(struct bme680_data *data, bool mode) 506 { 507 struct device *dev = regmap_get_device(data->regmap); 508 int ret; 509 510 if (mode) { 511 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 512 BME680_MODE_MASK, BME680_MODE_FORCED); 513 if (ret < 0) 514 dev_err(dev, "failed to set forced mode\n"); 515 516 } else { 517 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 518 BME680_MODE_MASK, BME680_MODE_SLEEP); 519 if (ret < 0) 520 dev_err(dev, "failed to set sleep mode\n"); 521 522 } 523 524 return ret; 525 } 526 527 static u8 bme680_oversampling_to_reg(u8 val) 528 { 529 return ilog2(val) + 1; 530 } 531 532 /* 533 * Taken from Bosch BME680 API: 534 * https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490 535 */ 536 static int bme680_wait_for_eoc(struct bme680_data *data) 537 { 538 struct device *dev = regmap_get_device(data->regmap); 539 int ret; 540 /* 541 * (Sum of oversampling ratios * time per oversampling) + 542 * TPH measurement + gas measurement + wait transition from forced mode 543 * + heater duration 544 */ 545 int wait_eoc_us = ((data->oversampling_temp + data->oversampling_press + 546 data->oversampling_humid) * 1936) + (477 * 4) + 547 (477 * 5) + 1000 + (data->heater_dur * 1000); 548 549 usleep_range(wait_eoc_us, wait_eoc_us + 100); 550 551 ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); 552 if (ret) { 553 dev_err(dev, "failed to read measurement status register.\n"); 554 return ret; 555 } 556 if (data->check & BME680_MEAS_BIT) { 557 dev_err(dev, "Device measurement cycle incomplete.\n"); 558 return -EBUSY; 559 } 560 if (!(data->check & BME680_NEW_DATA_BIT)) { 561 dev_err(dev, "No new data available from the device.\n"); 562 return -ENODATA; 563 } 564 565 return 0; 566 } 567 568 static int bme680_chip_config(struct bme680_data *data) 569 { 570 struct device *dev = regmap_get_device(data->regmap); 571 int ret; 572 u8 osrs; 573 574 osrs = FIELD_PREP( 575 BME680_OSRS_HUMIDITY_MASK, 576 bme680_oversampling_to_reg(data->oversampling_humid)); 577 /* 578 * Highly recommended to set oversampling of humidity before 579 * temperature/pressure oversampling. 580 */ 581 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_HUMIDITY, 582 BME680_OSRS_HUMIDITY_MASK, osrs); 583 if (ret < 0) { 584 dev_err(dev, "failed to write ctrl_hum register\n"); 585 return ret; 586 } 587 588 /* IIR filter settings */ 589 ret = regmap_update_bits(data->regmap, BME680_REG_CONFIG, 590 BME680_FILTER_MASK, 591 BME680_FILTER_COEFF_VAL); 592 if (ret < 0) { 593 dev_err(dev, "failed to write config register\n"); 594 return ret; 595 } 596 597 osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK, 598 bme680_oversampling_to_reg(data->oversampling_temp)) | 599 FIELD_PREP(BME680_OSRS_PRESS_MASK, 600 bme680_oversampling_to_reg(data->oversampling_press)); 601 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 602 BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK, 603 osrs); 604 if (ret < 0) { 605 dev_err(dev, "failed to write ctrl_meas register\n"); 606 return ret; 607 } 608 609 return 0; 610 } 611 612 static int bme680_gas_config(struct bme680_data *data) 613 { 614 struct device *dev = regmap_get_device(data->regmap); 615 int ret; 616 u8 heatr_res, heatr_dur; 617 618 /* Go to sleep */ 619 ret = bme680_set_mode(data, false); 620 if (ret < 0) 621 return ret; 622 623 heatr_res = bme680_calc_heater_res(data, data->heater_temp); 624 625 /* set target heater temperature */ 626 ret = regmap_write(data->regmap, BME680_REG_RES_HEAT_0, heatr_res); 627 if (ret < 0) { 628 dev_err(dev, "failed to write res_heat_0 register\n"); 629 return ret; 630 } 631 632 heatr_dur = bme680_calc_heater_dur(data->heater_dur); 633 634 /* set target heating duration */ 635 ret = regmap_write(data->regmap, BME680_REG_GAS_WAIT_0, heatr_dur); 636 if (ret < 0) { 637 dev_err(dev, "failed to write gas_wait_0 register\n"); 638 return ret; 639 } 640 641 /* Enable the gas sensor and select heater profile set-point 0 */ 642 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1, 643 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK, 644 FIELD_PREP(BME680_RUN_GAS_MASK, 1) | 645 FIELD_PREP(BME680_NB_CONV_MASK, 0)); 646 if (ret < 0) 647 dev_err(dev, "failed to write ctrl_gas_1 register\n"); 648 649 return ret; 650 } 651 652 static int bme680_read_temp(struct bme680_data *data, int *val) 653 { 654 int ret; 655 u32 adc_temp; 656 s16 comp_temp; 657 658 ret = bme680_read_temp_adc(data, &adc_temp); 659 if (ret) 660 return ret; 661 662 comp_temp = bme680_compensate_temp(data, adc_temp); 663 *val = comp_temp * 10; /* Centidegrees to millidegrees */ 664 return IIO_VAL_INT; 665 } 666 667 static int bme680_read_press(struct bme680_data *data, 668 int *val, int *val2) 669 { 670 int ret; 671 u32 adc_press; 672 s32 t_fine; 673 674 ret = bme680_get_t_fine(data, &t_fine); 675 if (ret) 676 return ret; 677 678 ret = bme680_read_press_adc(data, &adc_press); 679 if (ret) 680 return ret; 681 682 *val = bme680_compensate_press(data, adc_press, t_fine); 683 *val2 = 1000; 684 return IIO_VAL_FRACTIONAL; 685 } 686 687 static int bme680_read_humid(struct bme680_data *data, 688 int *val, int *val2) 689 { 690 int ret; 691 u32 adc_humidity, comp_humidity; 692 s32 t_fine; 693 694 ret = bme680_get_t_fine(data, &t_fine); 695 if (ret) 696 return ret; 697 698 ret = bme680_read_humid_adc(data, &adc_humidity); 699 if (ret) 700 return ret; 701 702 comp_humidity = bme680_compensate_humid(data, adc_humidity, t_fine); 703 704 *val = comp_humidity; 705 *val2 = 1000; 706 return IIO_VAL_FRACTIONAL; 707 } 708 709 static int bme680_read_gas(struct bme680_data *data, 710 int *val) 711 { 712 struct device *dev = regmap_get_device(data->regmap); 713 int ret; 714 u16 adc_gas_res, gas_regs_val; 715 u8 gas_range; 716 717 ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); 718 if (data->check & BME680_GAS_MEAS_BIT) { 719 dev_err(dev, "gas measurement incomplete\n"); 720 return -EBUSY; 721 } 722 723 ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB, 724 &data->be16, BME680_GAS_NUM_BYTES); 725 if (ret < 0) { 726 dev_err(dev, "failed to read gas resistance\n"); 727 return ret; 728 } 729 730 gas_regs_val = be16_to_cpu(data->be16); 731 adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val); 732 733 /* 734 * occurs if either the gas heating duration was insuffient 735 * to reach the target heater temperature or the target 736 * heater temperature was too high for the heater sink to 737 * reach. 738 */ 739 if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) { 740 dev_err(dev, "heater failed to reach the target temperature\n"); 741 return -EINVAL; 742 } 743 744 gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val); 745 746 *val = bme680_compensate_gas(data, adc_gas_res, gas_range); 747 return IIO_VAL_INT; 748 } 749 750 static int bme680_read_raw(struct iio_dev *indio_dev, 751 struct iio_chan_spec const *chan, 752 int *val, int *val2, long mask) 753 { 754 struct bme680_data *data = iio_priv(indio_dev); 755 int ret; 756 757 guard(mutex)(&data->lock); 758 759 /* set forced mode to trigger measurement */ 760 ret = bme680_set_mode(data, true); 761 if (ret < 0) 762 return ret; 763 764 ret = bme680_wait_for_eoc(data); 765 if (ret) 766 return ret; 767 768 switch (mask) { 769 case IIO_CHAN_INFO_PROCESSED: 770 switch (chan->type) { 771 case IIO_TEMP: 772 return bme680_read_temp(data, val); 773 case IIO_PRESSURE: 774 return bme680_read_press(data, val, val2); 775 case IIO_HUMIDITYRELATIVE: 776 return bme680_read_humid(data, val, val2); 777 case IIO_RESISTANCE: 778 return bme680_read_gas(data, val); 779 default: 780 return -EINVAL; 781 } 782 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 783 switch (chan->type) { 784 case IIO_TEMP: 785 *val = data->oversampling_temp; 786 return IIO_VAL_INT; 787 case IIO_PRESSURE: 788 *val = data->oversampling_press; 789 return IIO_VAL_INT; 790 case IIO_HUMIDITYRELATIVE: 791 *val = data->oversampling_humid; 792 return IIO_VAL_INT; 793 default: 794 return -EINVAL; 795 } 796 default: 797 return -EINVAL; 798 } 799 } 800 801 static bool bme680_is_valid_oversampling(int rate) 802 { 803 return (rate > 0 && rate <= 16 && is_power_of_2(rate)); 804 } 805 806 static int bme680_write_raw(struct iio_dev *indio_dev, 807 struct iio_chan_spec const *chan, 808 int val, int val2, long mask) 809 { 810 struct bme680_data *data = iio_priv(indio_dev); 811 812 guard(mutex)(&data->lock); 813 814 if (val2 != 0) 815 return -EINVAL; 816 817 switch (mask) { 818 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 819 { 820 if (!bme680_is_valid_oversampling(val)) 821 return -EINVAL; 822 823 switch (chan->type) { 824 case IIO_TEMP: 825 data->oversampling_temp = val; 826 break; 827 case IIO_PRESSURE: 828 data->oversampling_press = val; 829 break; 830 case IIO_HUMIDITYRELATIVE: 831 data->oversampling_humid = val; 832 break; 833 default: 834 return -EINVAL; 835 } 836 837 return bme680_chip_config(data); 838 } 839 default: 840 return -EINVAL; 841 } 842 } 843 844 static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16"; 845 846 static IIO_CONST_ATTR(oversampling_ratio_available, 847 bme680_oversampling_ratio_show); 848 849 static struct attribute *bme680_attributes[] = { 850 &iio_const_attr_oversampling_ratio_available.dev_attr.attr, 851 NULL, 852 }; 853 854 static const struct attribute_group bme680_attribute_group = { 855 .attrs = bme680_attributes, 856 }; 857 858 static const struct iio_info bme680_info = { 859 .read_raw = &bme680_read_raw, 860 .write_raw = &bme680_write_raw, 861 .attrs = &bme680_attribute_group, 862 }; 863 864 int bme680_core_probe(struct device *dev, struct regmap *regmap, 865 const char *name) 866 { 867 struct iio_dev *indio_dev; 868 struct bme680_data *data; 869 int ret; 870 871 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 872 if (!indio_dev) 873 return -ENOMEM; 874 875 data = iio_priv(indio_dev); 876 mutex_init(&data->lock); 877 dev_set_drvdata(dev, indio_dev); 878 data->regmap = regmap; 879 indio_dev->name = name; 880 indio_dev->channels = bme680_channels; 881 indio_dev->num_channels = ARRAY_SIZE(bme680_channels); 882 indio_dev->info = &bme680_info; 883 indio_dev->modes = INDIO_DIRECT_MODE; 884 885 /* default values for the sensor */ 886 data->oversampling_humid = 2; /* 2X oversampling rate */ 887 data->oversampling_press = 4; /* 4X oversampling rate */ 888 data->oversampling_temp = 8; /* 8X oversampling rate */ 889 data->heater_temp = 320; /* degree Celsius */ 890 data->heater_dur = 150; /* milliseconds */ 891 892 ret = regmap_write(regmap, BME680_REG_SOFT_RESET, 893 BME680_CMD_SOFTRESET); 894 if (ret < 0) 895 return dev_err_probe(dev, ret, "Failed to reset chip\n"); 896 897 usleep_range(BME680_STARTUP_TIME_US, BME680_STARTUP_TIME_US + 1000); 898 899 ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check); 900 if (ret < 0) 901 return dev_err_probe(dev, ret, "Error reading chip ID\n"); 902 903 if (data->check != BME680_CHIP_ID_VAL) { 904 dev_err(dev, "Wrong chip ID, got %x expected %x\n", 905 data->check, BME680_CHIP_ID_VAL); 906 return -ENODEV; 907 } 908 909 ret = bme680_read_calib(data, &data->bme680); 910 if (ret < 0) { 911 return dev_err_probe(dev, ret, 912 "failed to read calibration coefficients at probe\n"); 913 } 914 915 ret = bme680_chip_config(data); 916 if (ret < 0) 917 return dev_err_probe(dev, ret, 918 "failed to set chip_config data\n"); 919 920 ret = bme680_gas_config(data); 921 if (ret < 0) 922 return dev_err_probe(dev, ret, 923 "failed to set gas config data\n"); 924 925 return devm_iio_device_register(dev, indio_dev); 926 } 927 EXPORT_SYMBOL_NS_GPL(bme680_core_probe, IIO_BME680); 928 929 MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>"); 930 MODULE_DESCRIPTION("Bosch BME680 Driver"); 931 MODULE_LICENSE("GPL v2"); 932