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, iio_get_time_ns());
 228
 229 err:
 230         iio_trigger_notify_done(indio_dev->trig);
 231
 232         return IRQ_HANDLED;
 233 }
 234
 235 static int ms5611_read_raw(struct iio_dev *indio_dev,
 236                            struct iio_chan_spec const *chan,
 237                            int *val, int *val2, long mask)
 238 {
 239         int ret;
 240         s32 temp, pressure;
 241         struct ms5611_state *st = iio_priv(indio_dev);
 242
 243         switch (mask) {
 244         case IIO_CHAN_INFO_PROCESSED:
 245                 mutex_lock(&st->lock);
 246                 ret = ms5611_read_temp_and_pressure(indio_dev,
 247                                                     &temp, &pressure);
 248                 mutex_unlock(&st->lock);
 249                 if (ret < 0)
 250                         return ret;
 251
 252                 switch (chan->type) {
 253                 case IIO_TEMP:
 254                         *val = temp * 10;
 255                         return IIO_VAL_INT;
 256                 case IIO_PRESSURE:
 257                         *val = pressure / 1000;
 258                         *val2 = (pressure % 1000) * 1000;
 259                         return IIO_VAL_INT_PLUS_MICRO;
 260                 default:
 261                         return -EINVAL;
 262                 }
 263         case IIO_CHAN_INFO_SCALE:
 264                 switch (chan->type) {
 265                 case IIO_TEMP:
 266                         *val = 10;
 267                         return IIO_VAL_INT;
 268                 case IIO_PRESSURE:
 269                         *val = 0;
 270                         *val2 = 1000;
 271                         return IIO_VAL_INT_PLUS_MICRO;
 272                 default:
 273                         return -EINVAL;
 274                 }
 275         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 276                 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
 277                         break;
 278                 mutex_lock(&st->lock);
 279                 if (chan->type == IIO_TEMP)
 280                         *val = (int)st->temp_osr->rate;
 281                 else
 282                         *val = (int)st->pressure_osr->rate;
 283                 mutex_unlock(&st->lock);
 284                 return IIO_VAL_INT;
 285         }
 286
 287         return -EINVAL;
 288 }
 289
 290 static const struct ms5611_osr *ms5611_find_osr(int rate,
 291                                                 const struct ms5611_osr *osr,
 292                                                 size_t count)
 293 {
 294         unsigned int r;
 295
 296         for (r = 0; r < count; r++)
 297                 if ((unsigned short)rate == osr[r].rate)
 298                         break;
 299         if (r >= count)
 300                 return NULL;
 301         return &osr[r];
 302 }
 303
 304 static int ms5611_write_raw(struct iio_dev *indio_dev,
 305                             struct iio_chan_spec const *chan,
 306                             int val, int val2, long mask)
 307 {
 308         struct ms5611_state *st = iio_priv(indio_dev);
 309         const struct ms5611_osr *osr = NULL;
 310
 311         if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
 312                 return -EINVAL;
 313
 314         if (chan->type == IIO_TEMP)
 315                 osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
 316                                       ARRAY_SIZE(ms5611_avail_temp_osr));
 317         else if (chan->type == IIO_PRESSURE)
 318                 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
 319                                       ARRAY_SIZE(ms5611_avail_pressure_osr));
 320         if (!osr)
 321                 return -EINVAL;
 322
 323         mutex_lock(&st->lock);
 324
 325         if (iio_buffer_enabled(indio_dev)) {
 326                 mutex_unlock(&st->lock);
 327                 return -EBUSY;
 328         }
 329
 330         if (chan->type == IIO_TEMP)
 331                 st->temp_osr = osr;
 332         else
 333                 st->pressure_osr = osr;
 334
 335         mutex_unlock(&st->lock);
 336         return 0;
 337 }
 338
 339 static const unsigned long ms5611_scan_masks[] = {0x3, 0};
 340
 341 static struct ms5611_chip_info chip_info_tbl[] = {
 342         [MS5611] = {
 343                 .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
 344         },
 345         [MS5607] = {
 346                 .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
 347         }
 348 };
 349
 350 static const struct iio_chan_spec ms5611_channels[] = {
 351         {
 352                 .type = IIO_PRESSURE,
 353                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 354                         BIT(IIO_CHAN_INFO_SCALE) |
 355                         BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 356                 .scan_index = 0,
 357                 .scan_type = {
 358                         .sign = 's',
 359                         .realbits = 32,
 360                         .storagebits = 32,
 361                         .endianness = IIO_CPU,
 362                 },
 363         },
 364         {
 365                 .type = IIO_TEMP,
 366                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
 367                         BIT(IIO_CHAN_INFO_SCALE) |
 368                         BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 369                 .scan_index = 1,
 370                 .scan_type = {
 371                         .sign = 's',
 372                         .realbits = 32,
 373                         .storagebits = 32,
 374                         .endianness = IIO_CPU,
 375                 },
 376         },
 377         IIO_CHAN_SOFT_TIMESTAMP(2),
 378 };
 379
 380 static const struct iio_info ms5611_info = {
 381         .read_raw = &ms5611_read_raw,
 382         .write_raw = &ms5611_write_raw,
 383         .attrs = &ms5611_attribute_group,
 384         .driver_module = THIS_MODULE,
 385 };
 386
 387 static int ms5611_init(struct iio_dev *indio_dev)
 388 {
 389         int ret;
 390         struct ms5611_state *st = iio_priv(indio_dev);
 391
 392         /* Enable attached regulator if any. */
 393         st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
 394         if (!IS_ERR(st->vdd)) {
 395                 ret = regulator_enable(st->vdd);
 396                 if (ret) {
 397                         dev_err(indio_dev->dev.parent,
 398                                 "failed to enable Vdd supply: %d\n", ret);
 399                         return ret;
 400                 }
 401         } else {
 402                 ret = PTR_ERR(st->vdd);
 403                 if (ret != -ENODEV)
 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         if (!IS_ERR_OR_NULL(st->vdd))
 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         if (!IS_ERR_OR_NULL(st->vdd))
 428                 regulator_disable(st->vdd);
 429 }
 430
 431 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
 432                  const char *name, int type)
 433 {
 434         int ret;
 435         struct ms5611_state *st = iio_priv(indio_dev);
 436
 437         mutex_init(&st->lock);
 438         st->chip_info = &chip_info_tbl[type];
 439         st->temp_osr =
 440                 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
 441         st->pressure_osr =
 442                 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
 443                                            - 1];
 444         indio_dev->dev.parent = dev;
 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(ms5611_probe);
 478
 479 int 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         return 0;
 486 }
 487 EXPORT_SYMBOL(ms5611_remove);
 488
 489 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
 490 MODULE_DESCRIPTION("MS5611 core driver");
 491 MODULE_LICENSE("GPL v2");