1 // SPDX-License-Identifier: GPL-2.0+ 2 // Copyright IBM Corp 2019 3 /* 4 * The DPS310 is a barometric pressure and temperature sensor. 5 * Currently only reading a single temperature is supported by 6 * this driver. 7 * 8 * https://www.infineon.com/dgdl/?fileId=5546d462576f34750157750826c42242 9 * 10 * Temperature calculation: 11 * c0 * 0.5 + c1 * T_raw / kT °C 12 * 13 * TODO: 14 * - Optionally support the FIFO 15 */ 16 17 #include <linux/i2c.h> 18 #include <linux/limits.h> 19 #include <linux/math64.h> 20 #include <linux/module.h> 21 #include <linux/regmap.h> 22 23 #include <linux/iio/iio.h> 24 #include <linux/iio/sysfs.h> 25 26 #define DPS310_DEV_NAME "dps310" 27 28 #define DPS310_PRS_B0 0x00 29 #define DPS310_PRS_B1 0x01 30 #define DPS310_PRS_B2 0x02 31 #define DPS310_TMP_B0 0x03 32 #define DPS310_TMP_B1 0x04 33 #define DPS310_TMP_B2 0x05 34 #define DPS310_PRS_CFG 0x06 35 #define DPS310_PRS_RATE_BITS GENMASK(6, 4) 36 #define DPS310_PRS_PRC_BITS GENMASK(3, 0) 37 #define DPS310_TMP_CFG 0x07 38 #define DPS310_TMP_RATE_BITS GENMASK(6, 4) 39 #define DPS310_TMP_PRC_BITS GENMASK(3, 0) 40 #define DPS310_TMP_EXT BIT(7) 41 #define DPS310_MEAS_CFG 0x08 42 #define DPS310_MEAS_CTRL_BITS GENMASK(2, 0) 43 #define DPS310_PRS_EN BIT(0) 44 #define DPS310_TEMP_EN BIT(1) 45 #define DPS310_BACKGROUND BIT(2) 46 #define DPS310_PRS_RDY BIT(4) 47 #define DPS310_TMP_RDY BIT(5) 48 #define DPS310_SENSOR_RDY BIT(6) 49 #define DPS310_COEF_RDY BIT(7) 50 #define DPS310_CFG_REG 0x09 51 #define DPS310_INT_HL BIT(7) 52 #define DPS310_TMP_SHIFT_EN BIT(3) 53 #define DPS310_PRS_SHIFT_EN BIT(4) 54 #define DPS310_FIFO_EN BIT(5) 55 #define DPS310_SPI_EN BIT(6) 56 #define DPS310_RESET 0x0c 57 #define DPS310_RESET_MAGIC 0x09 58 #define DPS310_COEF_BASE 0x10 59 60 /* Make sure sleep time is <= 30ms for usleep_range */ 61 #define DPS310_POLL_SLEEP_US(t) min(30000, (t) / 8) 62 /* Silently handle error in rate value here */ 63 #define DPS310_POLL_TIMEOUT_US(rc) ((rc) <= 0 ? 1000000 : 1000000 / (rc)) 64 65 #define DPS310_PRS_BASE DPS310_PRS_B0 66 #define DPS310_TMP_BASE DPS310_TMP_B0 67 68 /* 69 * These values (defined in the spec) indicate how to scale the raw register 70 * values for each level of precision available. 71 */ 72 static const int scale_factors[] = { 73 524288, 74 1572864, 75 3670016, 76 7864320, 77 253952, 78 516096, 79 1040384, 80 2088960, 81 }; 82 83 struct dps310_data { 84 struct i2c_client *client; 85 struct regmap *regmap; 86 struct mutex lock; /* Lock for sequential HW access functions */ 87 88 s32 c0, c1; 89 s32 c00, c10, c20, c30, c01, c11, c21; 90 s32 pressure_raw; 91 s32 temp_raw; 92 bool timeout_recovery_failed; 93 }; 94 95 static const struct iio_chan_spec dps310_channels[] = { 96 { 97 .type = IIO_TEMP, 98 .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | 99 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 100 BIT(IIO_CHAN_INFO_PROCESSED), 101 }, 102 { 103 .type = IIO_PRESSURE, 104 .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | 105 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 106 BIT(IIO_CHAN_INFO_PROCESSED), 107 }, 108 }; 109 110 /* To be called after checking the COEF_RDY bit in MEAS_CFG */ dps310_get_coefs(struct dps310_data * data)111 static int dps310_get_coefs(struct dps310_data *data) 112 { 113 int rc; 114 u8 coef[18]; 115 u32 c0, c1; 116 u32 c00, c10, c20, c30, c01, c11, c21; 117 118 /* Read all sensor calibration coefficients from the COEF registers. */ 119 rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, 120 sizeof(coef)); 121 if (rc < 0) 122 return rc; 123 124 /* 125 * Calculate temperature calibration coefficients c0 and c1. The 126 * numbers are 12-bit 2's complement numbers. 127 */ 128 c0 = (coef[0] << 4) | (coef[1] >> 4); 129 data->c0 = sign_extend32(c0, 11); 130 131 c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; 132 data->c1 = sign_extend32(c1, 11); 133 134 /* 135 * Calculate pressure calibration coefficients. c00 and c10 are 20 bit 136 * 2's complement numbers, while the rest are 16 bit 2's complement 137 * numbers. 138 */ 139 c00 = (coef[3] << 12) | (coef[4] << 4) | (coef[5] >> 4); 140 data->c00 = sign_extend32(c00, 19); 141 142 c10 = ((coef[5] & GENMASK(3, 0)) << 16) | (coef[6] << 8) | coef[7]; 143 data->c10 = sign_extend32(c10, 19); 144 145 c01 = (coef[8] << 8) | coef[9]; 146 data->c01 = sign_extend32(c01, 15); 147 148 c11 = (coef[10] << 8) | coef[11]; 149 data->c11 = sign_extend32(c11, 15); 150 151 c20 = (coef[12] << 8) | coef[13]; 152 data->c20 = sign_extend32(c20, 15); 153 154 c21 = (coef[14] << 8) | coef[15]; 155 data->c21 = sign_extend32(c21, 15); 156 157 c30 = (coef[16] << 8) | coef[17]; 158 data->c30 = sign_extend32(c30, 15); 159 160 return 0; 161 } 162 163 /* 164 * Some versions of the chip will read temperatures in the ~60C range when 165 * it's actually ~20C. This is the manufacturer recommended workaround 166 * to correct the issue. The registers used below are undocumented. 167 */ dps310_temp_workaround(struct dps310_data * data)168 static int dps310_temp_workaround(struct dps310_data *data) 169 { 170 int rc; 171 int reg; 172 173 rc = regmap_read(data->regmap, 0x32, ®); 174 if (rc) 175 return rc; 176 177 /* 178 * If bit 1 is set then the device is okay, and the workaround does not 179 * need to be applied 180 */ 181 if (reg & BIT(1)) 182 return 0; 183 184 rc = regmap_write(data->regmap, 0x0e, 0xA5); 185 if (rc) 186 return rc; 187 188 rc = regmap_write(data->regmap, 0x0f, 0x96); 189 if (rc) 190 return rc; 191 192 rc = regmap_write(data->regmap, 0x62, 0x02); 193 if (rc) 194 return rc; 195 196 rc = regmap_write(data->regmap, 0x0e, 0x00); 197 if (rc) 198 return rc; 199 200 return regmap_write(data->regmap, 0x0f, 0x00); 201 } 202 dps310_startup(struct dps310_data * data)203 static int dps310_startup(struct dps310_data *data) 204 { 205 int rc; 206 int ready; 207 208 /* 209 * Set up pressure sensor in single sample, one measurement per second 210 * mode 211 */ 212 rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0); 213 if (rc) 214 return rc; 215 216 /* 217 * Set up external (MEMS) temperature sensor in single sample, one 218 * measurement per second mode 219 */ 220 rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT); 221 if (rc) 222 return rc; 223 224 /* Temp and pressure shifts are disabled when PRC <= 8 */ 225 rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, 226 DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0); 227 if (rc) 228 return rc; 229 230 /* MEAS_CFG doesn't update correctly unless first written with 0 */ 231 rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, 232 DPS310_MEAS_CTRL_BITS, 0); 233 if (rc) 234 return rc; 235 236 /* Turn on temperature and pressure measurement in the background */ 237 rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, 238 DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN | 239 DPS310_TEMP_EN | DPS310_BACKGROUND); 240 if (rc) 241 return rc; 242 243 /* 244 * Calibration coefficients required for reporting temperature. 245 * They are available 40ms after the device has started 246 */ 247 rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, 248 ready & DPS310_COEF_RDY, 10000, 40000); 249 if (rc) 250 return rc; 251 252 rc = dps310_get_coefs(data); 253 if (rc) 254 return rc; 255 256 return dps310_temp_workaround(data); 257 } 258 dps310_get_pres_precision(struct dps310_data * data)259 static int dps310_get_pres_precision(struct dps310_data *data) 260 { 261 int rc; 262 int val; 263 264 rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); 265 if (rc < 0) 266 return rc; 267 268 return BIT(val & GENMASK(2, 0)); 269 } 270 dps310_get_temp_precision(struct dps310_data * data)271 static int dps310_get_temp_precision(struct dps310_data *data) 272 { 273 int rc; 274 int val; 275 276 rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); 277 if (rc < 0) 278 return rc; 279 280 /* 281 * Scale factor is bottom 4 bits of the register, but 1111 is 282 * reserved so just grab bottom three 283 */ 284 return BIT(val & GENMASK(2, 0)); 285 } 286 287 /* Called with lock held */ dps310_set_pres_precision(struct dps310_data * data,int val)288 static int dps310_set_pres_precision(struct dps310_data *data, int val) 289 { 290 int rc; 291 u8 shift_en; 292 293 if (val < 0 || val > 128) 294 return -EINVAL; 295 296 shift_en = val >= 16 ? DPS310_PRS_SHIFT_EN : 0; 297 rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, 298 DPS310_PRS_SHIFT_EN, shift_en); 299 if (rc) 300 return rc; 301 302 return regmap_update_bits(data->regmap, DPS310_PRS_CFG, 303 DPS310_PRS_PRC_BITS, ilog2(val)); 304 } 305 306 /* Called with lock held */ dps310_set_temp_precision(struct dps310_data * data,int val)307 static int dps310_set_temp_precision(struct dps310_data *data, int val) 308 { 309 int rc; 310 u8 shift_en; 311 312 if (val < 0 || val > 128) 313 return -EINVAL; 314 315 shift_en = val >= 16 ? DPS310_TMP_SHIFT_EN : 0; 316 rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, 317 DPS310_TMP_SHIFT_EN, shift_en); 318 if (rc) 319 return rc; 320 321 return regmap_update_bits(data->regmap, DPS310_TMP_CFG, 322 DPS310_TMP_PRC_BITS, ilog2(val)); 323 } 324 325 /* Called with lock held */ dps310_set_pres_samp_freq(struct dps310_data * data,int freq)326 static int dps310_set_pres_samp_freq(struct dps310_data *data, int freq) 327 { 328 u8 val; 329 330 if (freq < 0 || freq > 128) 331 return -EINVAL; 332 333 val = ilog2(freq) << 4; 334 335 return regmap_update_bits(data->regmap, DPS310_PRS_CFG, 336 DPS310_PRS_RATE_BITS, val); 337 } 338 339 /* Called with lock held */ dps310_set_temp_samp_freq(struct dps310_data * data,int freq)340 static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) 341 { 342 u8 val; 343 344 if (freq < 0 || freq > 128) 345 return -EINVAL; 346 347 val = ilog2(freq) << 4; 348 349 return regmap_update_bits(data->regmap, DPS310_TMP_CFG, 350 DPS310_TMP_RATE_BITS, val); 351 } 352 dps310_get_pres_samp_freq(struct dps310_data * data)353 static int dps310_get_pres_samp_freq(struct dps310_data *data) 354 { 355 int rc; 356 int val; 357 358 rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); 359 if (rc < 0) 360 return rc; 361 362 return BIT((val & DPS310_PRS_RATE_BITS) >> 4); 363 } 364 dps310_get_temp_samp_freq(struct dps310_data * data)365 static int dps310_get_temp_samp_freq(struct dps310_data *data) 366 { 367 int rc; 368 int val; 369 370 rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); 371 if (rc < 0) 372 return rc; 373 374 return BIT((val & DPS310_TMP_RATE_BITS) >> 4); 375 } 376 dps310_get_pres_k(struct dps310_data * data)377 static int dps310_get_pres_k(struct dps310_data *data) 378 { 379 int rc = dps310_get_pres_precision(data); 380 381 if (rc < 0) 382 return rc; 383 384 return scale_factors[ilog2(rc)]; 385 } 386 dps310_get_temp_k(struct dps310_data * data)387 static int dps310_get_temp_k(struct dps310_data *data) 388 { 389 int rc = dps310_get_temp_precision(data); 390 391 if (rc < 0) 392 return rc; 393 394 return scale_factors[ilog2(rc)]; 395 } 396 dps310_reset_wait(struct dps310_data * data)397 static int dps310_reset_wait(struct dps310_data *data) 398 { 399 int rc; 400 401 rc = regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); 402 if (rc) 403 return rc; 404 405 /* Wait for device chip access: 15ms in specification */ 406 usleep_range(15000, 55000); 407 return 0; 408 } 409 dps310_reset_reinit(struct dps310_data * data)410 static int dps310_reset_reinit(struct dps310_data *data) 411 { 412 int rc; 413 414 rc = dps310_reset_wait(data); 415 if (rc) 416 return rc; 417 418 return dps310_startup(data); 419 } 420 dps310_ready_status(struct dps310_data * data,int ready_bit,int timeout)421 static int dps310_ready_status(struct dps310_data *data, int ready_bit, int timeout) 422 { 423 int sleep = DPS310_POLL_SLEEP_US(timeout); 424 int ready; 425 426 return regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, ready & ready_bit, 427 sleep, timeout); 428 } 429 dps310_ready(struct dps310_data * data,int ready_bit,int timeout)430 static int dps310_ready(struct dps310_data *data, int ready_bit, int timeout) 431 { 432 int rc; 433 434 rc = dps310_ready_status(data, ready_bit, timeout); 435 if (rc) { 436 if (rc == -ETIMEDOUT && !data->timeout_recovery_failed) { 437 /* Reset and reinitialize the chip. */ 438 if (dps310_reset_reinit(data)) { 439 data->timeout_recovery_failed = true; 440 } else { 441 /* Try again to get sensor ready status. */ 442 if (dps310_ready_status(data, ready_bit, timeout)) 443 data->timeout_recovery_failed = true; 444 else 445 return 0; 446 } 447 } 448 449 return rc; 450 } 451 452 data->timeout_recovery_failed = false; 453 return 0; 454 } 455 dps310_read_pres_raw(struct dps310_data * data)456 static int dps310_read_pres_raw(struct dps310_data *data) 457 { 458 int rc; 459 int rate; 460 int timeout; 461 s32 raw; 462 u8 val[3]; 463 464 if (mutex_lock_interruptible(&data->lock)) 465 return -EINTR; 466 467 rate = dps310_get_pres_samp_freq(data); 468 timeout = DPS310_POLL_TIMEOUT_US(rate); 469 470 /* Poll for sensor readiness; base the timeout upon the sample rate. */ 471 rc = dps310_ready(data, DPS310_PRS_RDY, timeout); 472 if (rc) 473 goto done; 474 475 rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)); 476 if (rc < 0) 477 goto done; 478 479 raw = (val[0] << 16) | (val[1] << 8) | val[2]; 480 data->pressure_raw = sign_extend32(raw, 23); 481 482 done: 483 mutex_unlock(&data->lock); 484 return rc; 485 } 486 487 /* Called with lock held */ dps310_read_temp_ready(struct dps310_data * data)488 static int dps310_read_temp_ready(struct dps310_data *data) 489 { 490 int rc; 491 u8 val[3]; 492 s32 raw; 493 494 rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)); 495 if (rc < 0) 496 return rc; 497 498 raw = (val[0] << 16) | (val[1] << 8) | val[2]; 499 data->temp_raw = sign_extend32(raw, 23); 500 501 return 0; 502 } 503 dps310_read_temp_raw(struct dps310_data * data)504 static int dps310_read_temp_raw(struct dps310_data *data) 505 { 506 int rc; 507 int rate; 508 int timeout; 509 510 if (mutex_lock_interruptible(&data->lock)) 511 return -EINTR; 512 513 rate = dps310_get_temp_samp_freq(data); 514 timeout = DPS310_POLL_TIMEOUT_US(rate); 515 516 /* Poll for sensor readiness; base the timeout upon the sample rate. */ 517 rc = dps310_ready(data, DPS310_TMP_RDY, timeout); 518 if (rc) 519 goto done; 520 521 rc = dps310_read_temp_ready(data); 522 523 done: 524 mutex_unlock(&data->lock); 525 return rc; 526 } 527 dps310_is_writeable_reg(struct device * dev,unsigned int reg)528 static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) 529 { 530 switch (reg) { 531 case DPS310_PRS_CFG: 532 case DPS310_TMP_CFG: 533 case DPS310_MEAS_CFG: 534 case DPS310_CFG_REG: 535 case DPS310_RESET: 536 /* No documentation available on the registers below */ 537 case 0x0e: 538 case 0x0f: 539 case 0x62: 540 return true; 541 default: 542 return false; 543 } 544 } 545 dps310_is_volatile_reg(struct device * dev,unsigned int reg)546 static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) 547 { 548 switch (reg) { 549 case DPS310_PRS_B0: 550 case DPS310_PRS_B1: 551 case DPS310_PRS_B2: 552 case DPS310_TMP_B0: 553 case DPS310_TMP_B1: 554 case DPS310_TMP_B2: 555 case DPS310_MEAS_CFG: 556 case 0x32: /* No documentation available on this register */ 557 return true; 558 default: 559 return false; 560 } 561 } 562 dps310_write_raw(struct iio_dev * iio,struct iio_chan_spec const * chan,int val,int val2,long mask)563 static int dps310_write_raw(struct iio_dev *iio, 564 struct iio_chan_spec const *chan, int val, 565 int val2, long mask) 566 { 567 int rc; 568 struct dps310_data *data = iio_priv(iio); 569 570 if (mutex_lock_interruptible(&data->lock)) 571 return -EINTR; 572 573 switch (mask) { 574 case IIO_CHAN_INFO_SAMP_FREQ: 575 switch (chan->type) { 576 case IIO_PRESSURE: 577 rc = dps310_set_pres_samp_freq(data, val); 578 break; 579 580 case IIO_TEMP: 581 rc = dps310_set_temp_samp_freq(data, val); 582 break; 583 584 default: 585 rc = -EINVAL; 586 break; 587 } 588 break; 589 590 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 591 switch (chan->type) { 592 case IIO_PRESSURE: 593 rc = dps310_set_pres_precision(data, val); 594 break; 595 596 case IIO_TEMP: 597 rc = dps310_set_temp_precision(data, val); 598 break; 599 600 default: 601 rc = -EINVAL; 602 break; 603 } 604 break; 605 606 default: 607 rc = -EINVAL; 608 break; 609 } 610 611 mutex_unlock(&data->lock); 612 return rc; 613 } 614 dps310_calculate_pressure(struct dps310_data * data)615 static int dps310_calculate_pressure(struct dps310_data *data) 616 { 617 int i; 618 int rc; 619 int t_ready; 620 int kpi = dps310_get_pres_k(data); 621 int kti = dps310_get_temp_k(data); 622 s64 rem = 0ULL; 623 s64 pressure = 0ULL; 624 s64 p; 625 s64 t; 626 s64 denoms[7]; 627 s64 nums[7]; 628 s64 rems[7]; 629 s64 kp; 630 s64 kt; 631 632 if (kpi < 0) 633 return kpi; 634 635 if (kti < 0) 636 return kti; 637 638 kp = (s64)kpi; 639 kt = (s64)kti; 640 641 /* Refresh temp if it's ready, otherwise just use the latest value */ 642 if (mutex_trylock(&data->lock)) { 643 rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &t_ready); 644 if (rc >= 0 && t_ready & DPS310_TMP_RDY) 645 dps310_read_temp_ready(data); 646 647 mutex_unlock(&data->lock); 648 } 649 650 p = (s64)data->pressure_raw; 651 t = (s64)data->temp_raw; 652 653 /* Section 4.9.1 of the DPS310 spec; algebra'd to avoid underflow */ 654 nums[0] = (s64)data->c00; 655 denoms[0] = 1LL; 656 nums[1] = p * (s64)data->c10; 657 denoms[1] = kp; 658 nums[2] = p * p * (s64)data->c20; 659 denoms[2] = kp * kp; 660 nums[3] = p * p * p * (s64)data->c30; 661 denoms[3] = kp * kp * kp; 662 nums[4] = t * (s64)data->c01; 663 denoms[4] = kt; 664 nums[5] = t * p * (s64)data->c11; 665 denoms[5] = kp * kt; 666 nums[6] = t * p * p * (s64)data->c21; 667 denoms[6] = kp * kp * kt; 668 669 /* Kernel lacks a div64_s64_rem function; denoms are all positive */ 670 for (i = 0; i < 7; ++i) { 671 u64 irem; 672 673 if (nums[i] < 0LL) { 674 pressure -= div64_u64_rem(-nums[i], denoms[i], &irem); 675 rems[i] = -irem; 676 } else { 677 pressure += div64_u64_rem(nums[i], denoms[i], &irem); 678 rems[i] = (s64)irem; 679 } 680 } 681 682 /* Increase precision and calculate the remainder sum */ 683 for (i = 0; i < 7; ++i) 684 rem += div64_s64((s64)rems[i] * 1000000000LL, denoms[i]); 685 686 pressure += div_s64(rem, 1000000000LL); 687 if (pressure < 0LL) 688 return -ERANGE; 689 690 return (int)min_t(s64, pressure, INT_MAX); 691 } 692 dps310_read_pressure(struct dps310_data * data,int * val,int * val2,long mask)693 static int dps310_read_pressure(struct dps310_data *data, int *val, int *val2, 694 long mask) 695 { 696 int rc; 697 698 switch (mask) { 699 case IIO_CHAN_INFO_SAMP_FREQ: 700 rc = dps310_get_pres_samp_freq(data); 701 if (rc < 0) 702 return rc; 703 704 *val = rc; 705 return IIO_VAL_INT; 706 707 case IIO_CHAN_INFO_PROCESSED: 708 rc = dps310_read_pres_raw(data); 709 if (rc) 710 return rc; 711 712 rc = dps310_calculate_pressure(data); 713 if (rc < 0) 714 return rc; 715 716 *val = rc; 717 *val2 = 1000; /* Convert Pa to KPa per IIO ABI */ 718 return IIO_VAL_FRACTIONAL; 719 720 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 721 rc = dps310_get_pres_precision(data); 722 if (rc < 0) 723 return rc; 724 725 *val = rc; 726 return IIO_VAL_INT; 727 728 default: 729 return -EINVAL; 730 } 731 } 732 dps310_calculate_temp(struct dps310_data * data,int * val)733 static int dps310_calculate_temp(struct dps310_data *data, int *val) 734 { 735 s64 c0; 736 s64 t; 737 int kt = dps310_get_temp_k(data); 738 739 if (kt < 0) 740 return kt; 741 742 /* Obtain inverse-scaled offset */ 743 c0 = div_s64((s64)kt * (s64)data->c0, 2); 744 745 /* Add the offset to the unscaled temperature */ 746 t = c0 + ((s64)data->temp_raw * (s64)data->c1); 747 748 /* Convert to milliCelsius and scale the temperature */ 749 *val = (int)div_s64(t * 1000LL, kt); 750 751 return 0; 752 } 753 dps310_read_temp(struct dps310_data * data,int * val,int * val2,long mask)754 static int dps310_read_temp(struct dps310_data *data, int *val, int *val2, 755 long mask) 756 { 757 int rc; 758 759 switch (mask) { 760 case IIO_CHAN_INFO_SAMP_FREQ: 761 rc = dps310_get_temp_samp_freq(data); 762 if (rc < 0) 763 return rc; 764 765 *val = rc; 766 return IIO_VAL_INT; 767 768 case IIO_CHAN_INFO_PROCESSED: 769 rc = dps310_read_temp_raw(data); 770 if (rc) 771 return rc; 772 773 rc = dps310_calculate_temp(data, val); 774 if (rc) 775 return rc; 776 777 return IIO_VAL_INT; 778 779 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 780 rc = dps310_get_temp_precision(data); 781 if (rc < 0) 782 return rc; 783 784 *val = rc; 785 return IIO_VAL_INT; 786 787 default: 788 return -EINVAL; 789 } 790 } 791 dps310_read_raw(struct iio_dev * iio,struct iio_chan_spec const * chan,int * val,int * val2,long mask)792 static int dps310_read_raw(struct iio_dev *iio, 793 struct iio_chan_spec const *chan, 794 int *val, int *val2, long mask) 795 { 796 struct dps310_data *data = iio_priv(iio); 797 798 switch (chan->type) { 799 case IIO_PRESSURE: 800 return dps310_read_pressure(data, val, val2, mask); 801 802 case IIO_TEMP: 803 return dps310_read_temp(data, val, val2, mask); 804 805 default: 806 return -EINVAL; 807 } 808 } 809 dps310_reset(void * action_data)810 static void dps310_reset(void *action_data) 811 { 812 struct dps310_data *data = action_data; 813 814 dps310_reset_wait(data); 815 } 816 817 static const struct regmap_config dps310_regmap_config = { 818 .reg_bits = 8, 819 .val_bits = 8, 820 .writeable_reg = dps310_is_writeable_reg, 821 .volatile_reg = dps310_is_volatile_reg, 822 .cache_type = REGCACHE_RBTREE, 823 .max_register = 0x62, /* No documentation available on this register */ 824 }; 825 826 static const struct iio_info dps310_info = { 827 .read_raw = dps310_read_raw, 828 .write_raw = dps310_write_raw, 829 }; 830 dps310_probe(struct i2c_client * client)831 static int dps310_probe(struct i2c_client *client) 832 { 833 const struct i2c_device_id *id = i2c_client_get_device_id(client); 834 struct dps310_data *data; 835 struct iio_dev *iio; 836 int rc; 837 838 iio = devm_iio_device_alloc(&client->dev, sizeof(*data)); 839 if (!iio) 840 return -ENOMEM; 841 842 data = iio_priv(iio); 843 data->client = client; 844 mutex_init(&data->lock); 845 846 iio->name = id->name; 847 iio->channels = dps310_channels; 848 iio->num_channels = ARRAY_SIZE(dps310_channels); 849 iio->info = &dps310_info; 850 iio->modes = INDIO_DIRECT_MODE; 851 852 data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config); 853 if (IS_ERR(data->regmap)) 854 return PTR_ERR(data->regmap); 855 856 /* Register to run the device reset when the device is removed */ 857 rc = devm_add_action_or_reset(&client->dev, dps310_reset, data); 858 if (rc) 859 return rc; 860 861 rc = dps310_startup(data); 862 if (rc) 863 return rc; 864 865 rc = devm_iio_device_register(&client->dev, iio); 866 if (rc) 867 return rc; 868 869 i2c_set_clientdata(client, iio); 870 871 return 0; 872 } 873 874 static const struct i2c_device_id dps310_id[] = { 875 { DPS310_DEV_NAME, 0 }, 876 {} 877 }; 878 MODULE_DEVICE_TABLE(i2c, dps310_id); 879 880 static const struct acpi_device_id dps310_acpi_match[] = { 881 { "IFX3100" }, 882 {} 883 }; 884 MODULE_DEVICE_TABLE(acpi, dps310_acpi_match); 885 886 static struct i2c_driver dps310_driver = { 887 .driver = { 888 .name = DPS310_DEV_NAME, 889 .acpi_match_table = dps310_acpi_match, 890 }, 891 .probe = dps310_probe, 892 .id_table = dps310_id, 893 }; 894 module_i2c_driver(dps310_driver); 895 896 MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); 897 MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); 898 MODULE_LICENSE("GPL v2"); 899