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(st, i, &st->prom[i]); 89 if (ret < 0) { 90 dev_err(&indio_dev->dev, 91 "failed to read prom at %d\n", i); 92 return ret; 93 } 94 } 95 96 if (!ms5611_prom_is_valid(st->prom, MS5611_PROM_WORDS_NB)) { 97 dev_err(&indio_dev->dev, "PROM integrity check failed\n"); 98 return -ENODEV; 99 } 100 101 return 0; 102 } 103 104 static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev, 105 s32 *temp, s32 *pressure) 106 { 107 int ret; 108 struct ms5611_state *st = iio_priv(indio_dev); 109 110 ret = st->read_adc_temp_and_pressure(st, temp, pressure); 111 if (ret < 0) { 112 dev_err(&indio_dev->dev, 113 "failed to read temperature and pressure\n"); 114 return ret; 115 } 116 117 return st->compensate_temp_and_pressure(st, temp, pressure); 118 } 119 120 static int ms5611_temp_and_pressure_compensate(struct ms5611_state *st, 121 s32 *temp, s32 *pressure) 122 { 123 s32 t = *temp, p = *pressure; 124 s64 off, sens, dt; 125 126 dt = t - (st->prom[5] << 8); 127 off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7); 128 sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8); 129 130 t = 2000 + ((st->prom[6] * dt) >> 23); 131 if (t < 2000) { 132 s64 off2, sens2, t2; 133 134 t2 = (dt * dt) >> 31; 135 off2 = (5 * (t - 2000) * (t - 2000)) >> 1; 136 sens2 = off2 >> 1; 137 138 if (t < -1500) { 139 s64 tmp = (t + 1500) * (t + 1500); 140 141 off2 += 7 * tmp; 142 sens2 += (11 * tmp) >> 1; 143 } 144 145 t -= t2; 146 off -= off2; 147 sens -= sens2; 148 } 149 150 *temp = t; 151 *pressure = (((p * sens) >> 21) - off) >> 15; 152 153 return 0; 154 } 155 156 static int ms5607_temp_and_pressure_compensate(struct ms5611_state *st, 157 s32 *temp, s32 *pressure) 158 { 159 s32 t = *temp, p = *pressure; 160 s64 off, sens, dt; 161 162 dt = t - (st->prom[5] << 8); 163 off = ((s64)st->prom[2] << 17) + ((st->prom[4] * dt) >> 6); 164 sens = ((s64)st->prom[1] << 16) + ((st->prom[3] * dt) >> 7); 165 166 t = 2000 + ((st->prom[6] * dt) >> 23); 167 if (t < 2000) { 168 s64 off2, sens2, t2, tmp; 169 170 t2 = (dt * dt) >> 31; 171 tmp = (t - 2000) * (t - 2000); 172 off2 = (61 * tmp) >> 4; 173 sens2 = tmp << 1; 174 175 if (t < -1500) { 176 tmp = (t + 1500) * (t + 1500); 177 off2 += 15 * tmp; 178 sens2 += 8 * tmp; 179 } 180 181 t -= t2; 182 off -= off2; 183 sens -= sens2; 184 } 185 186 *temp = t; 187 *pressure = (((p * sens) >> 21) - off) >> 15; 188 189 return 0; 190 } 191 192 static int ms5611_reset(struct iio_dev *indio_dev) 193 { 194 int ret; 195 struct ms5611_state *st = iio_priv(indio_dev); 196 197 ret = st->reset(st); 198 if (ret < 0) { 199 dev_err(&indio_dev->dev, "failed to reset device\n"); 200 return ret; 201 } 202 203 usleep_range(3000, 4000); 204 205 return 0; 206 } 207 208 static irqreturn_t ms5611_trigger_handler(int irq, void *p) 209 { 210 struct iio_poll_func *pf = p; 211 struct iio_dev *indio_dev = pf->indio_dev; 212 struct ms5611_state *st = iio_priv(indio_dev); 213 /* Ensure buffer elements are naturally aligned */ 214 struct { 215 s32 channels[2]; 216 s64 ts __aligned(8); 217 } scan; 218 int ret; 219 220 mutex_lock(&st->lock); 221 ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], 222 &scan.channels[0]); 223 mutex_unlock(&st->lock); 224 if (ret < 0) 225 goto err; 226 227 iio_push_to_buffers_with_timestamp(indio_dev, &scan, 228 iio_get_time_ns(indio_dev)); 229 230 err: 231 iio_trigger_notify_done(indio_dev->trig); 232 233 return IRQ_HANDLED; 234 } 235 236 static int ms5611_read_raw(struct iio_dev *indio_dev, 237 struct iio_chan_spec const *chan, 238 int *val, int *val2, long mask) 239 { 240 int ret; 241 s32 temp, pressure; 242 struct ms5611_state *st = iio_priv(indio_dev); 243 244 switch (mask) { 245 case IIO_CHAN_INFO_PROCESSED: 246 mutex_lock(&st->lock); 247 ret = ms5611_read_temp_and_pressure(indio_dev, 248 &temp, &pressure); 249 mutex_unlock(&st->lock); 250 if (ret < 0) 251 return ret; 252 253 switch (chan->type) { 254 case IIO_TEMP: 255 *val = temp * 10; 256 return IIO_VAL_INT; 257 case IIO_PRESSURE: 258 *val = pressure / 1000; 259 *val2 = (pressure % 1000) * 1000; 260 return IIO_VAL_INT_PLUS_MICRO; 261 default: 262 return -EINVAL; 263 } 264 case IIO_CHAN_INFO_SCALE: 265 switch (chan->type) { 266 case IIO_TEMP: 267 *val = 10; 268 return IIO_VAL_INT; 269 case IIO_PRESSURE: 270 *val = 0; 271 *val2 = 1000; 272 return IIO_VAL_INT_PLUS_MICRO; 273 default: 274 return -EINVAL; 275 } 276 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 277 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE) 278 break; 279 mutex_lock(&st->lock); 280 if (chan->type == IIO_TEMP) 281 *val = (int)st->temp_osr->rate; 282 else 283 *val = (int)st->pressure_osr->rate; 284 mutex_unlock(&st->lock); 285 return IIO_VAL_INT; 286 } 287 288 return -EINVAL; 289 } 290 291 static const struct ms5611_osr *ms5611_find_osr(int rate, 292 const struct ms5611_osr *osr, 293 size_t count) 294 { 295 unsigned int r; 296 297 for (r = 0; r < count; r++) 298 if ((unsigned short)rate == osr[r].rate) 299 break; 300 if (r >= count) 301 return NULL; 302 return &osr[r]; 303 } 304 305 static int ms5611_write_raw(struct iio_dev *indio_dev, 306 struct iio_chan_spec const *chan, 307 int val, int val2, long mask) 308 { 309 struct ms5611_state *st = iio_priv(indio_dev); 310 const struct ms5611_osr *osr = NULL; 311 int ret; 312 313 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) 314 return -EINVAL; 315 316 if (chan->type == IIO_TEMP) 317 osr = ms5611_find_osr(val, ms5611_avail_temp_osr, 318 ARRAY_SIZE(ms5611_avail_temp_osr)); 319 else if (chan->type == IIO_PRESSURE) 320 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr, 321 ARRAY_SIZE(ms5611_avail_pressure_osr)); 322 if (!osr) 323 return -EINVAL; 324 325 ret = iio_device_claim_direct_mode(indio_dev); 326 if (ret) 327 return ret; 328 329 mutex_lock(&st->lock); 330 331 if (chan->type == IIO_TEMP) 332 st->temp_osr = osr; 333 else 334 st->pressure_osr = osr; 335 336 mutex_unlock(&st->lock); 337 iio_device_release_direct_mode(indio_dev); 338 339 return 0; 340 } 341 342 static const unsigned long ms5611_scan_masks[] = {0x3, 0}; 343 344 static const struct iio_chan_spec ms5611_channels[] = { 345 { 346 .type = IIO_PRESSURE, 347 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 348 BIT(IIO_CHAN_INFO_SCALE) | 349 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 350 .scan_index = 0, 351 .scan_type = { 352 .sign = 's', 353 .realbits = 32, 354 .storagebits = 32, 355 .endianness = IIO_CPU, 356 }, 357 }, 358 { 359 .type = IIO_TEMP, 360 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 361 BIT(IIO_CHAN_INFO_SCALE) | 362 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 363 .scan_index = 1, 364 .scan_type = { 365 .sign = 's', 366 .realbits = 32, 367 .storagebits = 32, 368 .endianness = IIO_CPU, 369 }, 370 }, 371 IIO_CHAN_SOFT_TIMESTAMP(2), 372 }; 373 374 static const struct iio_info ms5611_info = { 375 .read_raw = &ms5611_read_raw, 376 .write_raw = &ms5611_write_raw, 377 .attrs = &ms5611_attribute_group, 378 }; 379 380 static int ms5611_init(struct iio_dev *indio_dev) 381 { 382 int ret; 383 struct ms5611_state *st = iio_priv(indio_dev); 384 385 /* Enable attached regulator if any. */ 386 st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd"); 387 if (IS_ERR(st->vdd)) 388 return PTR_ERR(st->vdd); 389 390 ret = regulator_enable(st->vdd); 391 if (ret) { 392 dev_err(indio_dev->dev.parent, 393 "failed to enable Vdd supply: %d\n", ret); 394 return ret; 395 } 396 397 ret = ms5611_reset(indio_dev); 398 if (ret < 0) 399 goto err_regulator_disable; 400 401 ret = ms5611_read_prom(indio_dev); 402 if (ret < 0) 403 goto err_regulator_disable; 404 405 return 0; 406 407 err_regulator_disable: 408 regulator_disable(st->vdd); 409 return ret; 410 } 411 412 static void ms5611_fini(const struct iio_dev *indio_dev) 413 { 414 const struct ms5611_state *st = iio_priv(indio_dev); 415 416 regulator_disable(st->vdd); 417 } 418 419 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev, 420 const char *name, int type) 421 { 422 int ret; 423 struct ms5611_state *st = iio_priv(indio_dev); 424 425 mutex_init(&st->lock); 426 427 switch (type) { 428 case MS5611: 429 st->compensate_temp_and_pressure = 430 ms5611_temp_and_pressure_compensate; 431 break; 432 case MS5607: 433 st->compensate_temp_and_pressure = 434 ms5607_temp_and_pressure_compensate; 435 break; 436 default: 437 return -EINVAL; 438 } 439 440 st->temp_osr = 441 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1]; 442 st->pressure_osr = 443 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr) 444 - 1]; 445 indio_dev->name = name; 446 indio_dev->info = &ms5611_info; 447 indio_dev->channels = ms5611_channels; 448 indio_dev->num_channels = ARRAY_SIZE(ms5611_channels); 449 indio_dev->modes = INDIO_DIRECT_MODE; 450 indio_dev->available_scan_masks = ms5611_scan_masks; 451 452 ret = ms5611_init(indio_dev); 453 if (ret < 0) 454 return ret; 455 456 ret = iio_triggered_buffer_setup(indio_dev, NULL, 457 ms5611_trigger_handler, NULL); 458 if (ret < 0) { 459 dev_err(dev, "iio triggered buffer setup failed\n"); 460 goto err_fini; 461 } 462 463 ret = iio_device_register(indio_dev); 464 if (ret < 0) { 465 dev_err(dev, "unable to register iio device\n"); 466 goto err_buffer_cleanup; 467 } 468 469 return 0; 470 471 err_buffer_cleanup: 472 iio_triggered_buffer_cleanup(indio_dev); 473 err_fini: 474 ms5611_fini(indio_dev); 475 return ret; 476 } 477 EXPORT_SYMBOL_NS(ms5611_probe, IIO_MS5611); 478 479 void ms5611_remove(struct iio_dev *indio_dev) 480 { 481 iio_device_unregister(indio_dev); 482 iio_triggered_buffer_cleanup(indio_dev); 483 ms5611_fini(indio_dev); 484 } 485 EXPORT_SYMBOL_NS(ms5611_remove, IIO_MS5611); 486 487 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>"); 488 MODULE_DESCRIPTION("MS5611 core driver"); 489 MODULE_LICENSE("GPL v2"); 490