developer | f9d3103 | 2023-03-03 20:54:33 +0800 | [diff] [blame] | 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 <= 20ms for usleep_range */ |
| 61 | #define DPS310_POLL_SLEEP_US(t) min(20000, (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 | }; |
| 93 | |
| 94 | static const struct iio_chan_spec dps310_channels[] = { |
| 95 | { |
| 96 | .type = IIO_TEMP, |
| 97 | .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | |
| 98 | BIT(IIO_CHAN_INFO_SAMP_FREQ) | |
| 99 | BIT(IIO_CHAN_INFO_PROCESSED), |
| 100 | }, |
| 101 | { |
| 102 | .type = IIO_PRESSURE, |
| 103 | .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | |
| 104 | BIT(IIO_CHAN_INFO_SAMP_FREQ) | |
| 105 | BIT(IIO_CHAN_INFO_PROCESSED), |
| 106 | }, |
| 107 | }; |
| 108 | |
| 109 | /* To be called after checking the COEF_RDY bit in MEAS_CFG */ |
| 110 | static int dps310_get_coefs(struct dps310_data *data) |
| 111 | { |
| 112 | int rc; |
| 113 | u8 coef[18]; |
| 114 | u32 c0, c1; |
| 115 | u32 c00, c10, c20, c30, c01, c11, c21; |
| 116 | |
| 117 | /* Read all sensor calibration coefficients from the COEF registers. */ |
| 118 | rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, |
| 119 | sizeof(coef)); |
| 120 | if (rc < 0) |
| 121 | return rc; |
| 122 | |
| 123 | /* |
| 124 | * Calculate temperature calibration coefficients c0 and c1. The |
| 125 | * numbers are 12-bit 2's complement numbers. |
| 126 | */ |
| 127 | c0 = (coef[0] << 4) | (coef[1] >> 4); |
| 128 | data->c0 = sign_extend32(c0, 11); |
| 129 | |
| 130 | c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; |
| 131 | data->c1 = sign_extend32(c1, 11); |
| 132 | |
| 133 | /* |
| 134 | * Calculate pressure calibration coefficients. c00 and c10 are 20 bit |
| 135 | * 2's complement numbers, while the rest are 16 bit 2's complement |
| 136 | * numbers. |
| 137 | */ |
| 138 | c00 = (coef[3] << 12) | (coef[4] << 4) | (coef[5] >> 4); |
| 139 | data->c00 = sign_extend32(c00, 19); |
| 140 | |
| 141 | c10 = ((coef[5] & GENMASK(3, 0)) << 16) | (coef[6] << 8) | coef[7]; |
| 142 | data->c10 = sign_extend32(c10, 19); |
| 143 | |
| 144 | c01 = (coef[8] << 8) | coef[9]; |
| 145 | data->c01 = sign_extend32(c01, 15); |
| 146 | |
| 147 | c11 = (coef[10] << 8) | coef[11]; |
| 148 | data->c11 = sign_extend32(c11, 15); |
| 149 | |
| 150 | c20 = (coef[12] << 8) | coef[13]; |
| 151 | data->c20 = sign_extend32(c20, 15); |
| 152 | |
| 153 | c21 = (coef[14] << 8) | coef[15]; |
| 154 | data->c21 = sign_extend32(c21, 15); |
| 155 | |
| 156 | c30 = (coef[16] << 8) | coef[17]; |
| 157 | data->c30 = sign_extend32(c30, 15); |
| 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | static int dps310_get_pres_precision(struct dps310_data *data) |
| 163 | { |
| 164 | int rc; |
| 165 | int val; |
| 166 | |
| 167 | rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); |
| 168 | if (rc < 0) |
| 169 | return rc; |
| 170 | |
| 171 | return BIT(val & GENMASK(2, 0)); |
| 172 | } |
| 173 | |
| 174 | static int dps310_get_temp_precision(struct dps310_data *data) |
| 175 | { |
| 176 | int rc; |
| 177 | int val; |
| 178 | |
| 179 | rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); |
| 180 | if (rc < 0) |
| 181 | return rc; |
| 182 | |
| 183 | /* |
| 184 | * Scale factor is bottom 4 bits of the register, but 1111 is |
| 185 | * reserved so just grab bottom three |
| 186 | */ |
| 187 | return BIT(val & GENMASK(2, 0)); |
| 188 | } |
| 189 | |
| 190 | /* Called with lock held */ |
| 191 | static int dps310_set_pres_precision(struct dps310_data *data, int val) |
| 192 | { |
| 193 | int rc; |
| 194 | u8 shift_en; |
| 195 | |
| 196 | if (val < 0 || val > 128) |
| 197 | return -EINVAL; |
| 198 | |
| 199 | shift_en = val >= 16 ? DPS310_PRS_SHIFT_EN : 0; |
| 200 | rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, |
| 201 | DPS310_PRS_SHIFT_EN, shift_en); |
| 202 | if (rc) |
| 203 | return rc; |
| 204 | |
| 205 | return regmap_update_bits(data->regmap, DPS310_PRS_CFG, |
| 206 | DPS310_PRS_PRC_BITS, ilog2(val)); |
| 207 | } |
| 208 | |
| 209 | /* Called with lock held */ |
| 210 | static int dps310_set_temp_precision(struct dps310_data *data, int val) |
| 211 | { |
| 212 | int rc; |
| 213 | u8 shift_en; |
| 214 | |
| 215 | if (val < 0 || val > 128) |
| 216 | return -EINVAL; |
| 217 | |
| 218 | shift_en = val >= 16 ? DPS310_TMP_SHIFT_EN : 0; |
| 219 | rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, |
| 220 | DPS310_TMP_SHIFT_EN, shift_en); |
| 221 | if (rc) |
| 222 | return rc; |
| 223 | |
| 224 | return regmap_update_bits(data->regmap, DPS310_TMP_CFG, |
| 225 | DPS310_TMP_PRC_BITS, ilog2(val)); |
| 226 | } |
| 227 | |
| 228 | /* Called with lock held */ |
| 229 | static int dps310_set_pres_samp_freq(struct dps310_data *data, int freq) |
| 230 | { |
| 231 | u8 val; |
| 232 | |
| 233 | if (freq < 0 || freq > 128) |
| 234 | return -EINVAL; |
| 235 | |
| 236 | val = ilog2(freq) << 4; |
| 237 | |
| 238 | return regmap_update_bits(data->regmap, DPS310_PRS_CFG, |
| 239 | DPS310_PRS_RATE_BITS, val); |
| 240 | } |
| 241 | |
| 242 | /* Called with lock held */ |
| 243 | static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) |
| 244 | { |
| 245 | u8 val; |
| 246 | |
| 247 | if (freq < 0 || freq > 128) |
| 248 | return -EINVAL; |
| 249 | |
| 250 | val = ilog2(freq) << 4; |
| 251 | |
| 252 | return regmap_update_bits(data->regmap, DPS310_TMP_CFG, |
| 253 | DPS310_TMP_RATE_BITS, val); |
| 254 | } |
| 255 | |
| 256 | static int dps310_get_pres_samp_freq(struct dps310_data *data) |
| 257 | { |
| 258 | int rc; |
| 259 | int val; |
| 260 | |
| 261 | rc = regmap_read(data->regmap, DPS310_PRS_CFG, &val); |
| 262 | if (rc < 0) |
| 263 | return rc; |
| 264 | |
| 265 | return BIT((val & DPS310_PRS_RATE_BITS) >> 4); |
| 266 | } |
| 267 | |
| 268 | static int dps310_get_temp_samp_freq(struct dps310_data *data) |
| 269 | { |
| 270 | int rc; |
| 271 | int val; |
| 272 | |
| 273 | rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); |
| 274 | if (rc < 0) |
| 275 | return rc; |
| 276 | |
| 277 | return BIT((val & DPS310_TMP_RATE_BITS) >> 4); |
| 278 | } |
| 279 | |
| 280 | static int dps310_get_pres_k(struct dps310_data *data) |
| 281 | { |
| 282 | int rc = dps310_get_pres_precision(data); |
| 283 | |
| 284 | if (rc < 0) |
| 285 | return rc; |
| 286 | |
| 287 | return scale_factors[ilog2(rc)]; |
| 288 | } |
| 289 | |
| 290 | static int dps310_get_temp_k(struct dps310_data *data) |
| 291 | { |
| 292 | int rc = dps310_get_temp_precision(data); |
| 293 | |
| 294 | if (rc < 0) |
| 295 | return rc; |
| 296 | |
| 297 | return scale_factors[ilog2(rc)]; |
| 298 | } |
| 299 | |
| 300 | static int dps310_read_pres_raw(struct dps310_data *data) |
| 301 | { |
| 302 | int rc; |
| 303 | int rate; |
| 304 | int ready; |
| 305 | int timeout; |
| 306 | s32 raw; |
| 307 | u8 val[3]; |
| 308 | |
| 309 | if (mutex_lock_interruptible(&data->lock)) |
| 310 | return -EINTR; |
| 311 | |
| 312 | rate = dps310_get_pres_samp_freq(data); |
| 313 | timeout = DPS310_POLL_TIMEOUT_US(rate); |
| 314 | |
| 315 | /* Poll for sensor readiness; base the timeout upon the sample rate. */ |
| 316 | rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, |
| 317 | ready & DPS310_PRS_RDY, |
| 318 | DPS310_POLL_SLEEP_US(timeout), timeout); |
| 319 | if (rc) |
| 320 | goto done; |
| 321 | |
| 322 | rc = regmap_bulk_read(data->regmap, DPS310_PRS_BASE, val, sizeof(val)); |
| 323 | if (rc < 0) |
| 324 | goto done; |
| 325 | |
| 326 | raw = (val[0] << 16) | (val[1] << 8) | val[2]; |
| 327 | data->pressure_raw = sign_extend32(raw, 23); |
| 328 | |
| 329 | done: |
| 330 | mutex_unlock(&data->lock); |
| 331 | return rc; |
| 332 | } |
| 333 | |
| 334 | /* Called with lock held */ |
| 335 | static int dps310_read_temp_ready(struct dps310_data *data) |
| 336 | { |
| 337 | int rc; |
| 338 | u8 val[3]; |
| 339 | s32 raw; |
| 340 | |
| 341 | rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)); |
| 342 | if (rc < 0) |
| 343 | return rc; |
| 344 | |
| 345 | raw = (val[0] << 16) | (val[1] << 8) | val[2]; |
| 346 | data->temp_raw = sign_extend32(raw, 23); |
| 347 | |
| 348 | return 0; |
| 349 | } |
| 350 | |
| 351 | static int dps310_read_temp_raw(struct dps310_data *data) |
| 352 | { |
| 353 | int rc; |
| 354 | int rate; |
| 355 | int ready; |
| 356 | int timeout; |
| 357 | |
| 358 | if (mutex_lock_interruptible(&data->lock)) |
| 359 | return -EINTR; |
| 360 | |
| 361 | rate = dps310_get_temp_samp_freq(data); |
| 362 | timeout = DPS310_POLL_TIMEOUT_US(rate); |
| 363 | |
| 364 | /* Poll for sensor readiness; base the timeout upon the sample rate. */ |
| 365 | rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, |
| 366 | ready & DPS310_TMP_RDY, |
| 367 | DPS310_POLL_SLEEP_US(timeout), timeout); |
| 368 | if (rc < 0) |
| 369 | goto done; |
| 370 | |
| 371 | rc = dps310_read_temp_ready(data); |
| 372 | |
| 373 | done: |
| 374 | mutex_unlock(&data->lock); |
| 375 | return rc; |
| 376 | } |
| 377 | |
| 378 | static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) |
| 379 | { |
| 380 | switch (reg) { |
| 381 | case DPS310_PRS_CFG: |
| 382 | case DPS310_TMP_CFG: |
| 383 | case DPS310_MEAS_CFG: |
| 384 | case DPS310_CFG_REG: |
| 385 | case DPS310_RESET: |
| 386 | /* No documentation available on the registers below */ |
| 387 | case 0x0e: |
| 388 | case 0x0f: |
| 389 | case 0x62: |
| 390 | return true; |
| 391 | default: |
| 392 | return false; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) |
| 397 | { |
| 398 | switch (reg) { |
| 399 | case DPS310_PRS_B0: |
| 400 | case DPS310_PRS_B1: |
| 401 | case DPS310_PRS_B2: |
| 402 | case DPS310_TMP_B0: |
| 403 | case DPS310_TMP_B1: |
| 404 | case DPS310_TMP_B2: |
| 405 | case DPS310_MEAS_CFG: |
| 406 | case 0x32: /* No documentation available on this register */ |
| 407 | return true; |
| 408 | default: |
| 409 | return false; |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | static int dps310_write_raw(struct iio_dev *iio, |
| 414 | struct iio_chan_spec const *chan, int val, |
| 415 | int val2, long mask) |
| 416 | { |
| 417 | int rc; |
| 418 | struct dps310_data *data = iio_priv(iio); |
| 419 | |
| 420 | if (mutex_lock_interruptible(&data->lock)) |
| 421 | return -EINTR; |
| 422 | |
| 423 | switch (mask) { |
| 424 | case IIO_CHAN_INFO_SAMP_FREQ: |
| 425 | switch (chan->type) { |
| 426 | case IIO_PRESSURE: |
| 427 | rc = dps310_set_pres_samp_freq(data, val); |
| 428 | break; |
| 429 | |
| 430 | case IIO_TEMP: |
| 431 | rc = dps310_set_temp_samp_freq(data, val); |
| 432 | break; |
| 433 | |
| 434 | default: |
| 435 | rc = -EINVAL; |
| 436 | break; |
| 437 | } |
| 438 | break; |
| 439 | |
| 440 | case IIO_CHAN_INFO_OVERSAMPLING_RATIO: |
| 441 | switch (chan->type) { |
| 442 | case IIO_PRESSURE: |
| 443 | rc = dps310_set_pres_precision(data, val); |
| 444 | break; |
| 445 | |
| 446 | case IIO_TEMP: |
| 447 | rc = dps310_set_temp_precision(data, val); |
| 448 | break; |
| 449 | |
| 450 | default: |
| 451 | rc = -EINVAL; |
| 452 | break; |
| 453 | } |
| 454 | break; |
| 455 | |
| 456 | default: |
| 457 | rc = -EINVAL; |
| 458 | break; |
| 459 | } |
| 460 | |
| 461 | mutex_unlock(&data->lock); |
| 462 | return rc; |
| 463 | } |
| 464 | |
| 465 | static int dps310_calculate_pressure(struct dps310_data *data) |
| 466 | { |
| 467 | int i; |
| 468 | int rc; |
| 469 | int t_ready; |
| 470 | int kpi = dps310_get_pres_k(data); |
| 471 | int kti = dps310_get_temp_k(data); |
| 472 | s64 rem = 0ULL; |
| 473 | s64 pressure = 0ULL; |
| 474 | s64 p; |
| 475 | s64 t; |
| 476 | s64 denoms[7]; |
| 477 | s64 nums[7]; |
| 478 | s64 rems[7]; |
| 479 | s64 kp; |
| 480 | s64 kt; |
| 481 | |
| 482 | if (kpi < 0) |
| 483 | return kpi; |
| 484 | |
| 485 | if (kti < 0) |
| 486 | return kti; |
| 487 | |
| 488 | kp = (s64)kpi; |
| 489 | kt = (s64)kti; |
| 490 | |
| 491 | /* Refresh temp if it's ready, otherwise just use the latest value */ |
| 492 | if (mutex_trylock(&data->lock)) { |
| 493 | rc = regmap_read(data->regmap, DPS310_MEAS_CFG, &t_ready); |
| 494 | if (rc >= 0 && t_ready & DPS310_TMP_RDY) |
| 495 | dps310_read_temp_ready(data); |
| 496 | |
| 497 | mutex_unlock(&data->lock); |
| 498 | } |
| 499 | |
| 500 | p = (s64)data->pressure_raw; |
| 501 | t = (s64)data->temp_raw; |
| 502 | |
| 503 | /* Section 4.9.1 of the DPS310 spec; algebra'd to avoid underflow */ |
| 504 | nums[0] = (s64)data->c00; |
| 505 | denoms[0] = 1LL; |
| 506 | nums[1] = p * (s64)data->c10; |
| 507 | denoms[1] = kp; |
| 508 | nums[2] = p * p * (s64)data->c20; |
| 509 | denoms[2] = kp * kp; |
| 510 | nums[3] = p * p * p * (s64)data->c30; |
| 511 | denoms[3] = kp * kp * kp; |
| 512 | nums[4] = t * (s64)data->c01; |
| 513 | denoms[4] = kt; |
| 514 | nums[5] = t * p * (s64)data->c11; |
| 515 | denoms[5] = kp * kt; |
| 516 | nums[6] = t * p * p * (s64)data->c21; |
| 517 | denoms[6] = kp * kp * kt; |
| 518 | |
| 519 | /* Kernel lacks a div64_s64_rem function; denoms are all positive */ |
| 520 | for (i = 0; i < 7; ++i) { |
| 521 | u64 irem; |
| 522 | |
| 523 | if (nums[i] < 0LL) { |
| 524 | pressure -= div64_u64_rem(-nums[i], denoms[i], &irem); |
| 525 | rems[i] = -irem; |
| 526 | } else { |
| 527 | pressure += div64_u64_rem(nums[i], denoms[i], &irem); |
| 528 | rems[i] = (s64)irem; |
| 529 | } |
| 530 | } |
| 531 | |
| 532 | /* Increase precision and calculate the remainder sum */ |
| 533 | for (i = 0; i < 7; ++i) |
| 534 | rem += div64_s64((s64)rems[i] * 1000000000LL, denoms[i]); |
| 535 | |
| 536 | pressure += div_s64(rem, 1000000000LL); |
| 537 | if (pressure < 0LL) |
| 538 | return -ERANGE; |
| 539 | |
| 540 | return (int)min_t(s64, pressure, INT_MAX); |
| 541 | } |
| 542 | |
| 543 | static int dps310_read_pressure(struct dps310_data *data, int *val, int *val2, |
| 544 | long mask) |
| 545 | { |
| 546 | int rc; |
| 547 | |
| 548 | switch (mask) { |
| 549 | case IIO_CHAN_INFO_SAMP_FREQ: |
| 550 | rc = dps310_get_pres_samp_freq(data); |
| 551 | if (rc < 0) |
| 552 | return rc; |
| 553 | |
| 554 | *val = rc; |
| 555 | return IIO_VAL_INT; |
| 556 | |
| 557 | case IIO_CHAN_INFO_PROCESSED: |
| 558 | rc = dps310_read_pres_raw(data); |
| 559 | if (rc) |
| 560 | return rc; |
| 561 | |
| 562 | rc = dps310_calculate_pressure(data); |
| 563 | if (rc < 0) |
| 564 | return rc; |
| 565 | |
| 566 | *val = rc; |
| 567 | *val2 = 1000; /* Convert Pa to KPa per IIO ABI */ |
| 568 | return IIO_VAL_FRACTIONAL; |
| 569 | |
| 570 | case IIO_CHAN_INFO_OVERSAMPLING_RATIO: |
| 571 | rc = dps310_get_pres_precision(data); |
| 572 | if (rc < 0) |
| 573 | return rc; |
| 574 | |
| 575 | *val = rc; |
| 576 | return IIO_VAL_INT; |
| 577 | |
| 578 | default: |
| 579 | return -EINVAL; |
| 580 | } |
| 581 | } |
| 582 | |
| 583 | static int dps310_calculate_temp(struct dps310_data *data) |
| 584 | { |
| 585 | s64 c0; |
| 586 | s64 t; |
| 587 | int kt = dps310_get_temp_k(data); |
| 588 | |
| 589 | if (kt < 0) |
| 590 | return kt; |
| 591 | |
| 592 | /* Obtain inverse-scaled offset */ |
| 593 | c0 = div_s64((s64)kt * (s64)data->c0, 2); |
| 594 | |
| 595 | /* Add the offset to the unscaled temperature */ |
| 596 | t = c0 + ((s64)data->temp_raw * (s64)data->c1); |
| 597 | |
| 598 | /* Convert to milliCelsius and scale the temperature */ |
| 599 | return (int)div_s64(t * 1000LL, kt); |
| 600 | } |
| 601 | |
| 602 | static int dps310_read_temp(struct dps310_data *data, int *val, int *val2, |
| 603 | long mask) |
| 604 | { |
| 605 | int rc; |
| 606 | |
| 607 | switch (mask) { |
| 608 | case IIO_CHAN_INFO_SAMP_FREQ: |
| 609 | rc = dps310_get_temp_samp_freq(data); |
| 610 | if (rc < 0) |
| 611 | return rc; |
| 612 | |
| 613 | *val = rc; |
| 614 | return IIO_VAL_INT; |
| 615 | |
| 616 | case IIO_CHAN_INFO_PROCESSED: |
| 617 | rc = dps310_read_temp_raw(data); |
| 618 | if (rc) |
| 619 | return rc; |
| 620 | |
| 621 | rc = dps310_calculate_temp(data); |
| 622 | if (rc < 0) |
| 623 | return rc; |
| 624 | |
| 625 | *val = rc; |
| 626 | return IIO_VAL_INT; |
| 627 | |
| 628 | case IIO_CHAN_INFO_OVERSAMPLING_RATIO: |
| 629 | rc = dps310_get_temp_precision(data); |
| 630 | if (rc < 0) |
| 631 | return rc; |
| 632 | |
| 633 | *val = rc; |
| 634 | return IIO_VAL_INT; |
| 635 | |
| 636 | default: |
| 637 | return -EINVAL; |
| 638 | } |
| 639 | } |
| 640 | |
| 641 | static int dps310_read_raw(struct iio_dev *iio, |
| 642 | struct iio_chan_spec const *chan, |
| 643 | int *val, int *val2, long mask) |
| 644 | { |
| 645 | struct dps310_data *data = iio_priv(iio); |
| 646 | |
| 647 | switch (chan->type) { |
| 648 | case IIO_PRESSURE: |
| 649 | return dps310_read_pressure(data, val, val2, mask); |
| 650 | |
| 651 | case IIO_TEMP: |
| 652 | return dps310_read_temp(data, val, val2, mask); |
| 653 | |
| 654 | default: |
| 655 | return -EINVAL; |
| 656 | } |
| 657 | } |
| 658 | |
| 659 | static void dps310_reset(void *action_data) |
| 660 | { |
| 661 | struct dps310_data *data = action_data; |
| 662 | |
| 663 | regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); |
| 664 | } |
| 665 | |
| 666 | static const struct regmap_config dps310_regmap_config = { |
| 667 | .reg_bits = 8, |
| 668 | .val_bits = 8, |
| 669 | .writeable_reg = dps310_is_writeable_reg, |
| 670 | .volatile_reg = dps310_is_volatile_reg, |
| 671 | .cache_type = REGCACHE_RBTREE, |
| 672 | .max_register = 0x62, /* No documentation available on this register */ |
| 673 | }; |
| 674 | |
| 675 | static const struct iio_info dps310_info = { |
| 676 | .read_raw = dps310_read_raw, |
| 677 | .write_raw = dps310_write_raw, |
| 678 | }; |
| 679 | |
| 680 | /* |
| 681 | * Some verions of chip will read temperatures in the ~60C range when |
| 682 | * its actually ~20C. This is the manufacturer recommended workaround |
| 683 | * to correct the issue. The registers used below are undocumented. |
| 684 | */ |
| 685 | static int dps310_temp_workaround(struct dps310_data *data) |
| 686 | { |
| 687 | int rc; |
| 688 | int reg; |
| 689 | |
| 690 | rc = regmap_read(data->regmap, 0x32, ®); |
| 691 | if (rc < 0) |
| 692 | return rc; |
| 693 | |
| 694 | /* |
| 695 | * If bit 1 is set then the device is okay, and the workaround does not |
| 696 | * need to be applied |
| 697 | */ |
| 698 | if (reg & BIT(1)) |
| 699 | return 0; |
| 700 | |
| 701 | rc = regmap_write(data->regmap, 0x0e, 0xA5); |
| 702 | if (rc < 0) |
| 703 | return rc; |
| 704 | |
| 705 | rc = regmap_write(data->regmap, 0x0f, 0x96); |
| 706 | if (rc < 0) |
| 707 | return rc; |
| 708 | |
| 709 | rc = regmap_write(data->regmap, 0x62, 0x02); |
| 710 | if (rc < 0) |
| 711 | return rc; |
| 712 | |
| 713 | rc = regmap_write(data->regmap, 0x0e, 0x00); |
| 714 | if (rc < 0) |
| 715 | return rc; |
| 716 | |
| 717 | return regmap_write(data->regmap, 0x0f, 0x00); |
| 718 | } |
| 719 | |
| 720 | static int dps310_probe(struct i2c_client *client, |
| 721 | const struct i2c_device_id *id) |
| 722 | { |
| 723 | struct dps310_data *data; |
| 724 | struct iio_dev *iio; |
| 725 | int rc, ready; |
| 726 | |
| 727 | iio = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| 728 | if (!iio) |
| 729 | return -ENOMEM; |
| 730 | |
| 731 | data = iio_priv(iio); |
| 732 | data->client = client; |
| 733 | mutex_init(&data->lock); |
| 734 | |
| 735 | iio->name = id->name; |
| 736 | iio->channels = dps310_channels; |
| 737 | iio->num_channels = ARRAY_SIZE(dps310_channels); |
| 738 | iio->info = &dps310_info; |
| 739 | iio->modes = INDIO_DIRECT_MODE; |
| 740 | |
| 741 | data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config); |
| 742 | if (IS_ERR(data->regmap)) |
| 743 | return PTR_ERR(data->regmap); |
| 744 | |
| 745 | /* Register to run the device reset when the device is removed */ |
| 746 | rc = devm_add_action_or_reset(&client->dev, dps310_reset, data); |
| 747 | if (rc) |
| 748 | return rc; |
| 749 | |
| 750 | /* |
| 751 | * Set up pressure sensor in single sample, one measurement per second |
| 752 | * mode |
| 753 | */ |
| 754 | rc = regmap_write(data->regmap, DPS310_PRS_CFG, 0); |
| 755 | |
| 756 | /* |
| 757 | * Set up external (MEMS) temperature sensor in single sample, one |
| 758 | * measurement per second mode |
| 759 | */ |
| 760 | rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT); |
| 761 | if (rc < 0) |
| 762 | return rc; |
| 763 | |
| 764 | /* Temp and pressure shifts are disabled when PRC <= 8 */ |
| 765 | rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, |
| 766 | DPS310_PRS_SHIFT_EN | DPS310_TMP_SHIFT_EN, 0); |
| 767 | if (rc < 0) |
| 768 | return rc; |
| 769 | |
| 770 | /* MEAS_CFG doesn't update correctly unless first written with 0 */ |
| 771 | rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, |
| 772 | DPS310_MEAS_CTRL_BITS, 0); |
| 773 | if (rc < 0) |
| 774 | return rc; |
| 775 | |
| 776 | /* Turn on temperature and pressure measurement in the background */ |
| 777 | rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, |
| 778 | DPS310_MEAS_CTRL_BITS, DPS310_PRS_EN | |
| 779 | DPS310_TEMP_EN | DPS310_BACKGROUND); |
| 780 | if (rc < 0) |
| 781 | return rc; |
| 782 | |
| 783 | /* |
| 784 | * Calibration coefficients required for reporting temperature. |
| 785 | * They are available 40ms after the device has started |
| 786 | */ |
| 787 | rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, |
| 788 | ready & DPS310_COEF_RDY, 10000, 40000); |
| 789 | if (rc < 0) |
| 790 | return rc; |
| 791 | |
| 792 | rc = dps310_get_coefs(data); |
| 793 | if (rc < 0) |
| 794 | return rc; |
| 795 | |
| 796 | rc = dps310_temp_workaround(data); |
| 797 | if (rc < 0) |
| 798 | return rc; |
| 799 | |
| 800 | rc = devm_iio_device_register(&client->dev, iio); |
| 801 | if (rc) |
| 802 | return rc; |
| 803 | |
| 804 | i2c_set_clientdata(client, iio); |
| 805 | |
| 806 | return 0; |
| 807 | } |
| 808 | |
| 809 | static int dps310_remove(struct i2c_client *client) |
| 810 | { |
| 811 | return 0; |
| 812 | } |
| 813 | |
| 814 | static const struct i2c_device_id dps310_id[] = { |
| 815 | { DPS310_DEV_NAME, 0 }, |
| 816 | {} |
| 817 | }; |
| 818 | MODULE_DEVICE_TABLE(i2c, dps310_id); |
| 819 | |
| 820 | static const struct acpi_device_id dps310_acpi_match[] = { |
| 821 | { "IFX3100" }, |
| 822 | {} |
| 823 | }; |
| 824 | MODULE_DEVICE_TABLE(acpi, dps310_acpi_match); |
| 825 | |
| 826 | static const struct of_device_id dps310_of_match[] = { |
| 827 | { .compatible = "infineon,dps310", }, |
| 828 | { } |
| 829 | }; |
| 830 | MODULE_DEVICE_TABLE(of, dps310_of_match); |
| 831 | |
| 832 | static struct i2c_driver dps310_driver = { |
| 833 | .driver = { |
| 834 | .name = DPS310_DEV_NAME, |
| 835 | .acpi_match_table = dps310_acpi_match, |
| 836 | .of_match_table = dps310_of_match, |
| 837 | }, |
| 838 | .probe = dps310_probe, |
| 839 | .remove = dps310_remove, |
| 840 | .id_table = dps310_id, |
| 841 | }; |
| 842 | module_i2c_driver(dps310_driver); |
| 843 | |
| 844 | MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); |
| 845 | MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); |
| 846 | MODULE_LICENSE("GPL v2"); |
| 847 | |
| 848 | |