1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * MS5611 pressure and temperature sensor driver 4 * 5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> 6 * 7 * Data sheet: 8 * http://www.meas-spec.com/downloads/MS5611-01BA03.pdf 9 * http://www.meas-spec.com/downloads/MS5607-02BA03.pdf 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/iio/iio.h> 15 #include <linux/delay.h> 16 #include <linux/regulator/consumer.h> 17 18 #include <linux/iio/sysfs.h> 19 #include <linux/iio/buffer.h> 20 #include <linux/iio/triggered_buffer.h> 21 #include <linux/iio/trigger_consumer.h> 22 #include "ms5611.h" 23 24 #define MS5611_INIT_OSR(_cmd, _conv_usec, _rate) \ 25 { .cmd = _cmd, .conv_usec = _conv_usec, .rate = _rate } 26 27 static const struct ms5611_osr ms5611_avail_pressure_osr[] = { 28 MS5611_INIT_OSR(0x40, 600, 256), 29 MS5611_INIT_OSR(0x42, 1170, 512), 30 MS5611_INIT_OSR(0x44, 2280, 1024), 31 MS5611_INIT_OSR(0x46, 4540, 2048), 32 MS5611_INIT_OSR(0x48, 9040, 4096) 33 }; 34 35 static const struct ms5611_osr ms5611_avail_temp_osr[] = { 36 MS5611_INIT_OSR(0x50, 600, 256), 37 MS5611_INIT_OSR(0x52, 1170, 512), 38 MS5611_INIT_OSR(0x54, 2280, 1024), 39 MS5611_INIT_OSR(0x56, 4540, 2048), 40 MS5611_INIT_OSR(0x58, 9040, 4096) 41 }; 42 43 static const char ms5611_show_osr[] = "256 512 1024 2048 4096"; 44 45 static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr); 46 47 static struct attribute *ms5611_attributes[] = { 48 &iio_const_attr_oversampling_ratio_available.dev_attr.attr, 49 NULL, 50 }; 51 52 static const struct attribute_group ms5611_attribute_group = { 53 .attrs = ms5611_attributes, 54 }; 55 56 static bool ms5611_prom_is_valid(u16 *prom, size_t len) 57 { 58 int i, j; 59 uint16_t crc = 0, crc_orig = prom[7] & 0x000F; 60 61 prom[7] &= 0xFF00; 62 63 for (i = 0; i < len * 2; i++) { 64 if (i % 2 == 1) 65 crc ^= prom[i >> 1] & 0x00FF; 66 else 67 crc ^= prom[i >> 1] >> 8; 68 69 for (j = 0; j < 8; j++) { 70 if (crc & 0x8000) 71 crc = (crc << 1) ^ 0x3000; 72 else 73 crc <<= 1; 74 } 75 } 76 77 crc = (crc >> 12) & 0x000F; 78 79 return crc_orig != 0x0000 && crc == crc_orig; 80 } 81 82 static int ms5611_read_prom(struct iio_dev *indio_dev) 83 { 84 int ret, i; 85 struct ms5611_state *st = iio_priv(indio_dev); 86 87 for (i = 0; i < MS5611_PROM_WORDS_NB; i++) { 88 ret = st->read_prom_word(&indio_dev->dev, 89 i, &st->chip_info->prom[i]); 90 if (ret < 0) { 91 dev_err(&indio_dev->dev, 92 "failed to read prom at %d\n", i); 93 return ret; 94 } 95 } 96 97 if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) { 98 dev_err(&indio_dev->dev, "PROM integrity check failed\n"); 99 return -ENODEV; 100 } 101 102 return 0; 103 } 104 105 static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev, 106 s32 *temp, s32 *pressure) 107 { 108 int ret; 109 struct ms5611_state *st = iio_priv(indio_dev); 110 111 ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure); 112 if (ret < 0) { 113 dev_err(&indio_dev->dev, 114 "failed to read temperature and pressure\n"); 115 return ret; 116 } 117 118 return st->chip_info->temp_and_pressure_compensate(st->chip_info, 119 temp, pressure); 120 } 121 122 static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info, 123 s32 *temp, s32 *pressure) 124 { 125 s32 t = *temp, p = *pressure; 126 s64 off, sens, dt; 127 128 dt = t - (chip_info->prom[5] << 8); 129 off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7); 130 sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8); 131 132 t = 2000 + ((chip_info->prom[6] * dt) >> 23); 133 if (t < 2000) { 134 s64 off2, sens2, t2; 135 136 t2 = (dt * dt) >> 31; 137 off2 = (5 * (t - 2000) * (t - 2000)) >> 1; 138 sens2 = off2 >> 1; 139 140 if (t < -1500) { 141 s64 tmp = (t + 1500) * (t + 1500); 142 143 off2 += 7 * tmp; 144 sens2 += (11 * tmp) >> 1; 145 } 146 147 t -= t2; 148 off -= off2; 149 sens -= sens2; 150 } 151 152 *temp = t; 153 *pressure = (((p * sens) >> 21) - off) >> 15; 154 155 return 0; 156 } 157 158 static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info, 159 s32 *temp, s32 *pressure) 160 { 161 s32 t = *temp, p = *pressure; 162 s64 off, sens, dt; 163 164 dt = t - (chip_info->prom[5] << 8); 165 off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6); 166 sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7); 167 168 t = 2000 + ((chip_info->prom[6] * dt) >> 23); 169 if (t < 2000) { 170 s64 off2, sens2, t2, tmp; 171 172 t2 = (dt * dt) >> 31; 173 tmp = (t - 2000) * (t - 2000); 174 off2 = (61 * tmp) >> 4; 175 sens2 = tmp << 1; 176 177 if (t < -1500) { 178 tmp = (t + 1500) * (t + 1500); 179 off2 += 15 * tmp; 180 sens2 += 8 * tmp; 181 } 182 183 t -= t2; 184 off -= off2; 185 sens -= sens2; 186 } 187 188 *temp = t; 189 *pressure = (((p * sens) >> 21) - off) >> 15; 190 191 return 0; 192 } 193 194 static int ms5611_reset(struct iio_dev *indio_dev) 195 { 196 int ret; 197 struct ms5611_state *st = iio_priv(indio_dev); 198 199 ret = st->reset(&indio_dev->dev); 200 if (ret < 0) { 201 dev_err(&indio_dev->dev, "failed to reset device\n"); 202 return ret; 203 } 204 205 usleep_range(3000, 4000); 206 207 return 0; 208 } 209 210 static irqreturn_t ms5611_trigger_handler(int irq, void *p) 211 { 212 struct iio_poll_func *pf = p; 213 struct iio_dev *indio_dev = pf->indio_dev; 214 struct ms5611_state *st = iio_priv(indio_dev); 215 /* Ensure buffer elements are naturally aligned */ 216 struct { 217 s32 channels[2]; 218 s64 ts __aligned(8); 219 } scan; 220 int ret; 221 222 mutex_lock(&st->lock); 223 ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], 224 &scan.channels[0]); 225 mutex_unlock(&st->lock); 226 if (ret < 0) 227 goto err; 228 229 iio_push_to_buffers_with_timestamp(indio_dev, &scan, 230 iio_get_time_ns(indio_dev)); 231 232 err: 233 iio_trigger_notify_done(indio_dev->trig); 234 235 return IRQ_HANDLED; 236 } 237 238 static int ms5611_read_raw(struct iio_dev *indio_dev, 239 struct iio_chan_spec const *chan, 240 int *val, int *val2, long mask) 241 { 242 int ret; 243 s32 temp, pressure; 244 struct ms5611_state *st = iio_priv(indio_dev); 245 246 switch (mask) { 247 case IIO_CHAN_INFO_PROCESSED: 248 mutex_lock(&st->lock); 249 ret = ms5611_read_temp_and_pressure(indio_dev, 250 &temp, &pressure); 251 mutex_unlock(&st->lock); 252 if (ret < 0) 253 return ret; 254 255 switch (chan->type) { 256 case IIO_TEMP: 257 *val = temp * 10; 258 return IIO_VAL_INT; 259 case IIO_PRESSURE: 260 *val = pressure / 1000; 261 *val2 = (pressure % 1000) * 1000; 262 return IIO_VAL_INT_PLUS_MICRO; 263 default: 264 return -EINVAL; 265 } 266 case IIO_CHAN_INFO_SCALE: 267 switch (chan->type) { 268 case IIO_TEMP: 269 *val = 10; 270 return IIO_VAL_INT; 271 case IIO_PRESSURE: 272 *val = 0; 273 *val2 = 1000; 274 return IIO_VAL_INT_PLUS_MICRO; 275 default: 276 return -EINVAL; 277 } 278 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 279 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE) 280 break; 281 mutex_lock(&st->lock); 282 if (chan->type == IIO_TEMP) 283 *val = (int)st->temp_osr->rate; 284 else 285 *val = (int)st->pressure_osr->rate; 286 mutex_unlock(&st->lock); 287 return IIO_VAL_INT; 288 } 289 290 return -EINVAL; 291 } 292 293 static const struct ms5611_osr *ms5611_find_osr(int rate, 294 const struct ms5611_osr *osr, 295 size_t count) 296 { 297 unsigned int r; 298 299 for (r = 0; r < count; r++) 300 if ((unsigned short)rate == osr[r].rate) 301 break; 302 if (r >= count) 303 return NULL; 304 return &osr[r]; 305 } 306 307 static int ms5611_write_raw(struct iio_dev *indio_dev, 308 struct iio_chan_spec const *chan, 309 int val, int val2, long mask) 310 { 311 struct ms5611_state *st = iio_priv(indio_dev); 312 const struct ms5611_osr *osr = NULL; 313 int ret; 314 315 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) 316 return -EINVAL; 317 318 if (chan->type == IIO_TEMP) 319 osr = ms5611_find_osr(val, ms5611_avail_temp_osr, 320 ARRAY_SIZE(ms5611_avail_temp_osr)); 321 else if (chan->type == IIO_PRESSURE) 322 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr, 323 ARRAY_SIZE(ms5611_avail_pressure_osr)); 324 if (!osr) 325 return -EINVAL; 326 327 ret = iio_device_claim_direct_mode(indio_dev); 328 if (ret) 329 return ret; 330 331 mutex_lock(&st->lock); 332 333 if (chan->type == IIO_TEMP) 334 st->temp_osr = osr; 335 else 336 st->pressure_osr = osr; 337 338 mutex_unlock(&st->lock); 339 iio_device_release_direct_mode(indio_dev); 340 341 return 0; 342 } 343 344 static const unsigned long ms5611_scan_masks[] = {0x3, 0}; 345 346 static struct ms5611_chip_info chip_info_tbl[] = { 347 [MS5611] = { 348 .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate, 349 }, 350 [MS5607] = { 351 .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate, 352 } 353 }; 354 355 static const struct iio_chan_spec ms5611_channels[] = { 356 { 357 .type = IIO_PRESSURE, 358 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 359 BIT(IIO_CHAN_INFO_SCALE) | 360 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 361 .scan_index = 0, 362 .scan_type = { 363 .sign = 's', 364 .realbits = 32, 365 .storagebits = 32, 366 .endianness = IIO_CPU, 367 }, 368 }, 369 { 370 .type = IIO_TEMP, 371 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 372 BIT(IIO_CHAN_INFO_SCALE) | 373 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 374 .scan_index = 1, 375 .scan_type = { 376 .sign = 's', 377 .realbits = 32, 378 .storagebits = 32, 379 .endianness = IIO_CPU, 380 }, 381 }, 382 IIO_CHAN_SOFT_TIMESTAMP(2), 383 }; 384 385 static const struct iio_info ms5611_info = { 386 .read_raw = &ms5611_read_raw, 387 .write_raw = &ms5611_write_raw, 388 .attrs = &ms5611_attribute_group, 389 }; 390 391 static int ms5611_init(struct iio_dev *indio_dev) 392 { 393 int ret; 394 struct ms5611_state *st = iio_priv(indio_dev); 395 396 /* Enable attached regulator if any. */ 397 st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd"); 398 if (IS_ERR(st->vdd)) 399 return PTR_ERR(st->vdd); 400 401 ret = regulator_enable(st->vdd); 402 if (ret) { 403 dev_err(indio_dev->dev.parent, 404 "failed to enable Vdd supply: %d\n", ret); 405 return ret; 406 } 407 408 ret = ms5611_reset(indio_dev); 409 if (ret < 0) 410 goto err_regulator_disable; 411 412 ret = ms5611_read_prom(indio_dev); 413 if (ret < 0) 414 goto err_regulator_disable; 415 416 return 0; 417 418 err_regulator_disable: 419 regulator_disable(st->vdd); 420 return ret; 421 } 422 423 static void ms5611_fini(const struct iio_dev *indio_dev) 424 { 425 const struct ms5611_state *st = iio_priv(indio_dev); 426 427 regulator_disable(st->vdd); 428 } 429 430 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev, 431 const char *name, int type) 432 { 433 int ret; 434 struct ms5611_state *st = iio_priv(indio_dev); 435 436 mutex_init(&st->lock); 437 st->chip_info = &chip_info_tbl[type]; 438 st->temp_osr = 439 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1]; 440 st->pressure_osr = 441 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr) 442 - 1]; 443 indio_dev->name = name; 444 indio_dev->info = &ms5611_info; 445 indio_dev->channels = ms5611_channels; 446 indio_dev->num_channels = ARRAY_SIZE(ms5611_channels); 447 indio_dev->modes = INDIO_DIRECT_MODE; 448 indio_dev->available_scan_masks = ms5611_scan_masks; 449 450 ret = ms5611_init(indio_dev); 451 if (ret < 0) 452 return ret; 453 454 ret = iio_triggered_buffer_setup(indio_dev, NULL, 455 ms5611_trigger_handler, NULL); 456 if (ret < 0) { 457 dev_err(dev, "iio triggered buffer setup failed\n"); 458 goto err_fini; 459 } 460 461 ret = iio_device_register(indio_dev); 462 if (ret < 0) { 463 dev_err(dev, "unable to register iio device\n"); 464 goto err_buffer_cleanup; 465 } 466 467 return 0; 468 469 err_buffer_cleanup: 470 iio_triggered_buffer_cleanup(indio_dev); 471 err_fini: 472 ms5611_fini(indio_dev); 473 return ret; 474 } 475 EXPORT_SYMBOL(ms5611_probe); 476 477 int ms5611_remove(struct iio_dev *indio_dev) 478 { 479 iio_device_unregister(indio_dev); 480 iio_triggered_buffer_cleanup(indio_dev); 481 ms5611_fini(indio_dev); 482 483 return 0; 484 } 485 EXPORT_SYMBOL(ms5611_remove); 486 487 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); 488 MODULE_DESCRIPTION("MS5611 core driver"); 489 MODULE_LICENSE("GPL v2"); 490