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