drivers/iio/pressure/ms5611_core.c

   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         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 struct ms5611_chip_info chip_info_tbl[] = {
 345         [MS5611] = {
 346                 .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
 347         },
 348         [MS5607] = {
 349                 .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
 350         }
 351 };
 352
 353 static const struct iio_chan_spec ms5611_channels[] = {
 354         {
 355                 .type = IIO_PRESSURE,
 356                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 357                         BIT(IIO_CHAN_INFO_SCALE) |
 358                         BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 359                 .scan_index = 0,
 360                 .scan_type = {
 361                         .sign = 's',
 362                         .realbits = 32,
 363                         .storagebits = 32,
 364                         .endianness = IIO_CPU,
 365                 },
 366         },
 367         {
 368                 .type = IIO_TEMP,
 369                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 370                         BIT(IIO_CHAN_INFO_SCALE) |
 371                         BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 372                 .scan_index = 1,
 373                 .scan_type = {
 374                         .sign = 's',
 375                         .realbits = 32,
 376                         .storagebits = 32,
 377                         .endianness = IIO_CPU,
 378                 },
 379         },
 380         IIO_CHAN_SOFT_TIMESTAMP(2),
 381 };
 382
 383 static const struct iio_info ms5611_info = {
 384         .read_raw = &ms5611_read_raw,
 385         .write_raw = &ms5611_write_raw,
 386         .attrs = &ms5611_attribute_group,
 387         .driver_module = THIS_MODULE,
 388 };
 389
 390 static int ms5611_init(struct iio_dev *indio_dev)
 391 {
 392         int ret;
 393         struct ms5611_state *st = iio_priv(indio_dev);
 394
 395         /* Enable attached regulator if any. */
 396         st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
 397         if (IS_ERR(st->vdd))
 398                 return PTR_ERR(st->vdd);
 399
 400         ret = regulator_enable(st->vdd);
 401         if (ret) {
 402                 dev_err(indio_dev->dev.parent,
 403                         "failed to enable Vdd supply: %d\n", ret);
 404                 return ret;
 405         }
 406
 407         ret = ms5611_reset(indio_dev);
 408         if (ret < 0)
 409                 goto err_regulator_disable;
 410
 411         ret = ms5611_read_prom(indio_dev);
 412         if (ret < 0)
 413                 goto err_regulator_disable;
 414
 415         return 0;
 416
 417 err_regulator_disable:
 418         regulator_disable(st->vdd);
 419         return ret;
 420 }
 421
 422 static void ms5611_fini(const struct iio_dev *indio_dev)
 423 {
 424         const struct ms5611_state *st = iio_priv(indio_dev);
 425
 426         regulator_disable(st->vdd);
 427 }
 428
 429 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
 430                  const char *name, int type)
 431 {
 432         int ret;
 433         struct ms5611_state *st = iio_priv(indio_dev);
 434
 435         mutex_init(&st->lock);
 436         st->chip_info = &chip_info_tbl[type];
 437         st->temp_osr =
 438                 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
 439         st->pressure_osr =
 440                 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
 441                                            - 1];
 442         indio_dev->dev.parent = dev;
 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");