drivers/staging/iio/cdc/ad7746.c

   1 /*
   2  * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
   3  *
   4  * Copyright 2011 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2.
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/sysfs.h>
  14 #include <linux/i2c.h>
  15 #include <linux/delay.h>
  16 #include <linux/module.h>
  17 #include <linux/stat.h>
  18
  19 #include "../iio.h"
  20 #include "../sysfs.h"
  21
  22 #include "ad7746.h"
  23
  24 /*
  25  * AD7746 Register Definition
  26  */
  27
  28 #define AD7746_REG_STATUS               0
  29 #define AD7746_REG_CAP_DATA_HIGH        1
  30 #define AD7746_REG_CAP_DATA_MID         2
  31 #define AD7746_REG_CAP_DATA_LOW         3
  32 #define AD7746_REG_VT_DATA_HIGH         4
  33 #define AD7746_REG_VT_DATA_MID          5
  34 #define AD7746_REG_VT_DATA_LOW          6
  35 #define AD7746_REG_CAP_SETUP            7
  36 #define AD7746_REG_VT_SETUP             8
  37 #define AD7746_REG_EXC_SETUP            9
  38 #define AD7746_REG_CFG                  10
  39 #define AD7746_REG_CAPDACA              11
  40 #define AD7746_REG_CAPDACB              12
  41 #define AD7746_REG_CAP_OFFH             13
  42 #define AD7746_REG_CAP_OFFL             14
  43 #define AD7746_REG_CAP_GAINH            15
  44 #define AD7746_REG_CAP_GAINL            16
  45 #define AD7746_REG_VOLT_GAINH           17
  46 #define AD7746_REG_VOLT_GAINL           18
  47
  48 /* Status Register Bit Designations (AD7746_REG_STATUS) */
  49 #define AD7746_STATUS_EXCERR            (1 << 3)
  50 #define AD7746_STATUS_RDY               (1 << 2)
  51 #define AD7746_STATUS_RDYVT             (1 << 1)
  52 #define AD7746_STATUS_RDYCAP            (1 << 0)
  53
  54 /* Capacitive Channel Setup Register Bit Designations (AD7746_REG_CAP_SETUP) */
  55 #define AD7746_CAPSETUP_CAPEN           (1 << 7)
  56 #define AD7746_CAPSETUP_CIN2            (1 << 6) /* AD7746 only */
  57 #define AD7746_CAPSETUP_CAPDIFF         (1 << 5)
  58 #define AD7746_CAPSETUP_CACHOP          (1 << 0)
  59
  60 /* Voltage/Temperature Setup Register Bit Designations (AD7746_REG_VT_SETUP) */
  61 #define AD7746_VTSETUP_VTEN             (1 << 7)
  62 #define AD7746_VTSETUP_VTMD_INT_TEMP    (0 << 5)
  63 #define AD7746_VTSETUP_VTMD_EXT_TEMP    (1 << 5)
  64 #define AD7746_VTSETUP_VTMD_VDD_MON     (2 << 5)
  65 #define AD7746_VTSETUP_VTMD_EXT_VIN     (3 << 5)
  66 #define AD7746_VTSETUP_EXTREF           (1 << 4)
  67 #define AD7746_VTSETUP_VTSHORT          (1 << 1)
  68 #define AD7746_VTSETUP_VTCHOP           (1 << 0)
  69
  70 /* Excitation Setup Register Bit Designations (AD7746_REG_EXC_SETUP) */
  71 #define AD7746_EXCSETUP_CLKCTRL         (1 << 7)
  72 #define AD7746_EXCSETUP_EXCON           (1 << 6)
  73 #define AD7746_EXCSETUP_EXCB            (1 << 5)
  74 #define AD7746_EXCSETUP_NEXCB           (1 << 4)
  75 #define AD7746_EXCSETUP_EXCA            (1 << 3)
  76 #define AD7746_EXCSETUP_NEXCA           (1 << 2)
  77 #define AD7746_EXCSETUP_EXCLVL(x)       (((x) & 0x3) << 0)
  78
  79 /* Config Register Bit Designations (AD7746_REG_CFG) */
  80 #define AD7746_CONF_VTFS(x)             ((x) << 6)
  81 #define AD7746_CONF_CAPFS(x)            ((x) << 3)
  82 #define AD7746_CONF_MODE_IDLE           (0 << 0)
  83 #define AD7746_CONF_MODE_CONT_CONV      (1 << 0)
  84 #define AD7746_CONF_MODE_SINGLE_CONV    (2 << 0)
  85 #define AD7746_CONF_MODE_PWRDN          (3 << 0)
  86 #define AD7746_CONF_MODE_OFFS_CAL       (5 << 0)
  87 #define AD7746_CONF_MODE_GAIN_CAL       (6 << 0)
  88
  89 /* CAPDAC Register Bit Designations (AD7746_REG_CAPDACx) */
  90 #define AD7746_CAPDAC_DACEN             (1 << 7)
  91 #define AD7746_CAPDAC_DACP(x)           ((x) & 0x7F)
  92
  93 /*
  94  * struct ad7746_chip_info - chip specifc information
  95  */
  96
  97 struct ad7746_chip_info {
  98         struct i2c_client *client;
  99         /*
 100          * Capacitive channel digital filter setup;
 101          * conversion time/update rate setup per channel
 102          */
 103         u8      config;
 104         u8      cap_setup;
 105         u8      vt_setup;
 106         u8      capdac[2][2];
 107         s8      capdac_set;
 108 };
 109
 110 enum ad7746_chan {
 111         VIN,
 112         VIN_VDD,
 113         TEMP_INT,
 114         TEMP_EXT,
 115         CIN1,
 116         CIN1_DIFF,
 117         CIN2,
 118         CIN2_DIFF,
 119 };
 120
 121 static const struct iio_chan_spec ad7746_channels[] = {
 122         [VIN] = {
 123                 .type = IIO_VOLTAGE,
 124                 .indexed = 1,
 125                 .channel = 0,
 126                 .info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT,
 127                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 128                         AD7746_VTSETUP_VTMD_EXT_VIN,
 129         },
 130         [VIN_VDD] = {
 131                 .type = IIO_VOLTAGE,
 132                 .indexed = 1,
 133                 .channel = 1,
 134                 .extend_name = "supply",
 135                 .info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT,
 136                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 137                         AD7746_VTSETUP_VTMD_VDD_MON,
 138         },
 139         [TEMP_INT] = {
 140                 .type = IIO_TEMP,
 141                 .indexed = 1,
 142                 .channel = 0,
 143                 .processed_val = IIO_PROCESSED,
 144                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 145                         AD7746_VTSETUP_VTMD_INT_TEMP,
 146         },
 147         [TEMP_EXT] = {
 148                 .type = IIO_TEMP,
 149                 .indexed = 1,
 150                 .channel = 1,
 151                 .processed_val = IIO_PROCESSED,
 152                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 153                         AD7746_VTSETUP_VTMD_EXT_TEMP,
 154         },
 155         [CIN1] = {
 156                 .type = IIO_CAPACITANCE,
 157                 .indexed = 1,
 158                 .channel = 0,
 159                 .info_mask = IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |
 160                 IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT |
 161                 IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 162                 IIO_CHAN_INFO_SCALE_SHARED_BIT,
 163                 .address = AD7746_REG_CAP_DATA_HIGH << 8,
 164         },
 165         [CIN1_DIFF] = {
 166                 .type = IIO_CAPACITANCE,
 167                 .differential = 1,
 168                 .indexed = 1,
 169                 .channel = 0,
 170                 .channel2 = 2,
 171                 .info_mask = IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |
 172                 IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT |
 173                 IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 174                 IIO_CHAN_INFO_SCALE_SHARED_BIT,
 175                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 176                         AD7746_CAPSETUP_CAPDIFF
 177         },
 178         [CIN2] = {
 179                 .type = IIO_CAPACITANCE,
 180                 .indexed = 1,
 181                 .channel = 1,
 182                 .info_mask = IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |
 183                 IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT |
 184                 IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 185                 IIO_CHAN_INFO_SCALE_SHARED_BIT,
 186                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 187                         AD7746_CAPSETUP_CIN2,
 188         },
 189         [CIN2_DIFF] = {
 190                 .type = IIO_CAPACITANCE,
 191                 .differential = 1,
 192                 .indexed = 1,
 193                 .channel = 1,
 194                 .channel2 = 3,
 195                 .info_mask = IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |
 196                 IIO_CHAN_INFO_CALIBBIAS_SHARED_BIT |
 197                 IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
 198                 IIO_CHAN_INFO_SCALE_SHARED_BIT,
 199                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 200                         AD7746_CAPSETUP_CAPDIFF | AD7746_CAPSETUP_CIN2,
 201         }
 202 };
 203
 204 /* Values are Update Rate (Hz), Conversion Time (ms) + 1*/
 205 static const unsigned char ad7746_vt_filter_rate_table[][2] = {
 206         {50, 20 + 1}, {31, 32 + 1}, {16, 62 + 1}, {8, 122 + 1},
 207 };
 208
 209 static const unsigned char ad7746_cap_filter_rate_table[][2] = {
 210         {91, 11 + 1}, {84, 12 + 1}, {50, 20 + 1}, {26, 38 + 1},
 211         {16, 62 + 1}, {13, 77 + 1}, {11, 92 + 1}, {9, 110 + 1},
 212 };
 213
 214 static int ad7746_select_channel(struct iio_dev *indio_dev,
 215                             struct iio_chan_spec const *chan)
 216 {
 217         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 218         int ret, delay;
 219         u8 vt_setup, cap_setup;
 220
 221         switch (chan->type) {
 222         case IIO_CAPACITANCE:
 223                 cap_setup = (chan->address & 0xFF) | AD7746_CAPSETUP_CAPEN;
 224                 vt_setup = chip->vt_setup & ~AD7746_VTSETUP_VTEN;
 225                 delay = ad7746_cap_filter_rate_table[(chip->config >> 3) &
 226                         0x7][1];
 227
 228                 if (chip->capdac_set != chan->channel) {
 229                         ret = i2c_smbus_write_byte_data(chip->client,
 230                                 AD7746_REG_CAPDACA,
 231                                 chip->capdac[chan->channel][0]);
 232                         if (ret < 0)
 233                                 return ret;
 234                         ret = i2c_smbus_write_byte_data(chip->client,
 235                                 AD7746_REG_CAPDACB,
 236                                 chip->capdac[chan->channel][1]);
 237                         if (ret < 0)
 238                                 return ret;
 239
 240                         chip->capdac_set = chan->channel;
 241                 }
 242                 break;
 243         case IIO_VOLTAGE:
 244         case IIO_TEMP:
 245                 vt_setup = (chan->address & 0xFF) | AD7746_VTSETUP_VTEN;
 246                 cap_setup = chip->cap_setup & ~AD7746_CAPSETUP_CAPEN;
 247                 delay = ad7746_cap_filter_rate_table[(chip->config >> 6) &
 248                         0x3][1];
 249                 break;
 250         default:
 251                 return -EINVAL;
 252         }
 253
 254         if (chip->cap_setup != cap_setup) {
 255                 ret = i2c_smbus_write_byte_data(chip->client,
 256                                                 AD7746_REG_CAP_SETUP,
 257                                                 cap_setup);
 258                 if (ret < 0)
 259                         return ret;
 260
 261                 chip->cap_setup = cap_setup;
 262         }
 263
 264         if (chip->vt_setup != vt_setup) {
 265                 ret = i2c_smbus_write_byte_data(chip->client,
 266                                                 AD7746_REG_VT_SETUP,
 267                                                 vt_setup);
 268                 if (ret < 0)
 269                         return ret;
 270
 271                 chip->vt_setup = vt_setup;
 272         }
 273
 274         return delay;
 275 }
 276
 277 static inline ssize_t ad7746_start_calib(struct device *dev,
 278                                          struct device_attribute *attr,
 279                                          const char *buf,
 280                                          size_t len,
 281                                          u8 regval)
 282 {
 283         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 284         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 285         bool doit;
 286         int ret, timeout = 10;
 287
 288         ret = strtobool(buf, &doit);
 289         if (ret < 0)
 290                 return ret;
 291
 292         if (!doit)
 293                 return 0;
 294
 295         mutex_lock(&indio_dev->mlock);
 296         regval |= chip->config;
 297         ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG, regval);
 298         if (ret < 0) {
 299                 mutex_unlock(&indio_dev->mlock);
 300                 return ret;
 301         }
 302
 303         do {
 304                 msleep(20);
 305                 ret = i2c_smbus_read_byte_data(chip->client, AD7746_REG_CFG);
 306                 if (ret < 0) {
 307                         mutex_unlock(&indio_dev->mlock);
 308                         return ret;
 309                 }
 310         } while ((ret == regval) && timeout--);
 311
 312         mutex_unlock(&indio_dev->mlock);
 313
 314         return len;
 315 }
 316
 317 static ssize_t ad7746_start_offset_calib(struct device *dev,
 318                                          struct device_attribute *attr,
 319                                          const char *buf,
 320                                          size_t len)
 321 {
 322         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 323         int ret = ad7746_select_channel(indio_dev,
 324                               &ad7746_channels[to_iio_dev_attr(attr)->address]);
 325         if (ret < 0)
 326                 return ret;
 327
 328         return ad7746_start_calib(dev, attr, buf, len,
 329                                   AD7746_CONF_MODE_OFFS_CAL);
 330 }
 331
 332 static ssize_t ad7746_start_gain_calib(struct device *dev,
 333                                        struct device_attribute *attr,
 334                                        const char *buf,
 335                                        size_t len)
 336 {
 337         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 338         int ret = ad7746_select_channel(indio_dev,
 339                               &ad7746_channels[to_iio_dev_attr(attr)->address]);
 340         if (ret < 0)
 341                 return ret;
 342
 343         return ad7746_start_calib(dev, attr, buf, len,
 344                                   AD7746_CONF_MODE_GAIN_CAL);
 345 }
 346
 347 static IIO_DEVICE_ATTR(in_capacitance0_calibbias_calibration,
 348                        S_IWUSR, NULL, ad7746_start_offset_calib, CIN1);
 349 static IIO_DEVICE_ATTR(in_capacitance1_calibbias_calibration,
 350                        S_IWUSR, NULL, ad7746_start_offset_calib, CIN2);
 351 static IIO_DEVICE_ATTR(in_capacitance0_calibscale_calibration,
 352                        S_IWUSR, NULL, ad7746_start_gain_calib, CIN1);
 353 static IIO_DEVICE_ATTR(in_capacitance1_calibscale_calibration,
 354                        S_IWUSR, NULL, ad7746_start_gain_calib, CIN2);
 355 static IIO_DEVICE_ATTR(in_voltage0_calibscale_calibration,
 356                        S_IWUSR, NULL, ad7746_start_gain_calib, VIN);
 357
 358 static ssize_t ad7746_show_cap_filter_rate_setup(struct device *dev,
 359                 struct device_attribute *attr,
 360                 char *buf)
 361 {
 362         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 363         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 364
 365         return sprintf(buf, "%d\n", ad7746_cap_filter_rate_table[
 366                         (chip->config >> 3) & 0x7][0]);
 367 }
 368
 369 static ssize_t ad7746_store_cap_filter_rate_setup(struct device *dev,
 370                 struct device_attribute *attr,
 371                 const char *buf,
 372                 size_t len)
 373 {
 374         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 375         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 376         u8 data;
 377         int ret, i;
 378
 379         ret = kstrtou8(buf, 10, &data);
 380         if (ret < 0)
 381                 return ret;
 382
 383         for (i = 0; i < ARRAY_SIZE(ad7746_cap_filter_rate_table); i++)
 384                 if (data >= ad7746_cap_filter_rate_table[i][0])
 385                         break;
 386
 387         if (i >= ARRAY_SIZE(ad7746_cap_filter_rate_table))
 388                 i = ARRAY_SIZE(ad7746_cap_filter_rate_table) - 1;
 389
 390         mutex_lock(&indio_dev->mlock);
 391         chip->config &= ~AD7746_CONF_CAPFS(0x7);
 392         chip->config |= AD7746_CONF_CAPFS(i);
 393         mutex_unlock(&indio_dev->mlock);
 394
 395         return len;
 396 }
 397
 398 static ssize_t ad7746_show_vt_filter_rate_setup(struct device *dev,
 399                 struct device_attribute *attr,
 400                 char *buf)
 401 {
 402         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 403         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 404
 405         return sprintf(buf, "%d\n", ad7746_vt_filter_rate_table[
 406                         (chip->config >> 6) & 0x3][0]);
 407 }
 408
 409 static ssize_t ad7746_store_vt_filter_rate_setup(struct device *dev,
 410                 struct device_attribute *attr,
 411                 const char *buf,
 412                 size_t len)
 413 {
 414         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 415         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 416         u8 data;
 417         int ret, i;
 418
 419         ret = kstrtou8(buf, 10, &data);
 420         if (ret < 0)
 421                 return ret;
 422
 423         for (i = 0; i < ARRAY_SIZE(ad7746_vt_filter_rate_table); i++)
 424                 if (data >= ad7746_vt_filter_rate_table[i][0])
 425                         break;
 426
 427         if (i >= ARRAY_SIZE(ad7746_vt_filter_rate_table))
 428                 i = ARRAY_SIZE(ad7746_vt_filter_rate_table) - 1;
 429
 430         mutex_lock(&indio_dev->mlock);
 431         chip->config &= ~AD7746_CONF_VTFS(0x3);
 432         chip->config |= AD7746_CONF_VTFS(i);
 433         mutex_unlock(&indio_dev->mlock);
 434
 435         return len;
 436 }
 437
 438 static IIO_DEVICE_ATTR(in_capacitance_sampling_frequency,
 439                        S_IRUGO | S_IWUSR, ad7746_show_cap_filter_rate_setup,
 440                         ad7746_store_cap_filter_rate_setup, 0);
 441
 442 static IIO_DEVICE_ATTR(in_voltage_sampling_frequency,
 443                        S_IRUGO | S_IWUSR, ad7746_show_vt_filter_rate_setup,
 444                        ad7746_store_vt_filter_rate_setup, 0);
 445
 446 static IIO_CONST_ATTR(in_voltage_sampling_frequency_available, "50 31 16 8");
 447 static IIO_CONST_ATTR(in_capacitance_sampling_frequency_available,
 448                        "91 84 50 26 16 13 11 9");
 449
 450 static struct attribute *ad7746_attributes[] = {
 451         &iio_dev_attr_in_capacitance_sampling_frequency.dev_attr.attr,
 452         &iio_dev_attr_in_voltage_sampling_frequency.dev_attr.attr,
 453         &iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
 454         &iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
 455         &iio_dev_attr_in_capacitance1_calibscale_calibration.dev_attr.attr,
 456         &iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
 457         &iio_dev_attr_in_voltage0_calibscale_calibration.dev_attr.attr,
 458         &iio_const_attr_in_voltage_sampling_frequency_available.dev_attr.attr,
 459         &iio_const_attr_in_capacitance_sampling_frequency_available.
 460         dev_attr.attr,
 461         NULL,
 462 };
 463
 464 static const struct attribute_group ad7746_attribute_group = {
 465         .attrs = ad7746_attributes,
 466 };
 467
 468 static int ad7746_write_raw(struct iio_dev *indio_dev,
 469                             struct iio_chan_spec const *chan,
 470                             int val,
 471                             int val2,
 472                             long mask)
 473 {
 474         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 475         int ret, reg;
 476
 477         mutex_lock(&indio_dev->mlock);
 478
 479         switch (mask) {
 480         case IIO_CHAN_INFO_CALIBSCALE:
 481                 if (val != 1) {
 482                         ret = -EINVAL;
 483                         goto out;
 484                 }
 485
 486                 val = (val2 * 1024) / 15625;
 487
 488                 switch (chan->type) {
 489                 case IIO_CAPACITANCE:
 490                         reg = AD7746_REG_CAP_GAINH;
 491                         break;
 492                 case IIO_VOLTAGE:
 493                         reg = AD7746_REG_VOLT_GAINH;
 494                         break;
 495                 default:
 496                         ret = -EINVAL;
 497                         goto out;
 498                 }
 499
 500                 ret = i2c_smbus_write_word_data(chip->client, reg, swab16(val));
 501                 if (ret < 0)
 502                         goto out;
 503
 504                 ret = 0;
 505                 break;
 506         case IIO_CHAN_INFO_CALIBBIAS:
 507                 if ((val < 0) | (val > 0xFFFF)) {
 508                         ret = -EINVAL;
 509                         goto out;
 510                 }
 511                 ret = i2c_smbus_write_word_data(chip->client,
 512                                 AD7746_REG_CAP_OFFH, swab16(val));
 513                 if (ret < 0)
 514                         goto out;
 515
 516                 ret = 0;
 517                 break;
 518         case IIO_CHAN_INFO_OFFSET:
 519                 if ((val < 0) | (val > 43008000)) { /* 21pF */
 520                         ret = -EINVAL;
 521                         goto out;
 522                 }
 523
 524                 /* CAPDAC Scale = 21pF_typ / 127
 525                  * CIN Scale = 8.192pF / 2^24
 526                  * Offset Scale = CAPDAC Scale / CIN Scale = 338646
 527                  * */
 528
 529                 val /= 338646;
 530
 531                 chip->capdac[chan->channel][chan->differential] = (val > 0 ?
 532                         AD7746_CAPDAC_DACP(val) | AD7746_CAPDAC_DACEN : 0);
 533
 534                 ret = i2c_smbus_write_byte_data(chip->client,
 535                         AD7746_REG_CAPDACA,
 536                         chip->capdac[chan->channel][0]);
 537                 if (ret < 0)
 538                         goto out;
 539                 ret = i2c_smbus_write_byte_data(chip->client,
 540                         AD7746_REG_CAPDACB,
 541                         chip->capdac[chan->channel][1]);
 542                 if (ret < 0)
 543                         goto out;
 544
 545                 chip->capdac_set = chan->channel;
 546
 547                 ret = 0;
 548                 break;
 549         default:
 550                 ret = -EINVAL;
 551         }
 552
 553 out:
 554         mutex_unlock(&indio_dev->mlock);
 555         return ret;
 556 }
 557
 558 static int ad7746_read_raw(struct iio_dev *indio_dev,
 559                            struct iio_chan_spec const *chan,
 560                            int *val, int *val2,
 561                            long mask)
 562 {
 563         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 564         int ret, delay;
 565         u8 regval, reg;
 566
 567         union {
 568                 u32 d32;
 569                 u8 d8[4];
 570         } data;
 571
 572         mutex_lock(&indio_dev->mlock);
 573
 574         switch (mask) {
 575         case 0:
 576                 ret = ad7746_select_channel(indio_dev, chan);
 577                 if (ret < 0)
 578                         goto out;
 579                 delay = ret;
 580
 581                 regval = chip->config | AD7746_CONF_MODE_SINGLE_CONV;
 582                 ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG,
 583                                 regval);
 584                 if (ret < 0)
 585                         goto out;
 586
 587                 msleep(delay);
 588                 /* Now read the actual register */
 589
 590                 ret = i2c_smbus_read_i2c_block_data(chip->client,
 591                         chan->address >> 8, 3, &data.d8[1]);
 592
 593                 if (ret < 0)
 594                         goto out;
 595
 596                 *val = (be32_to_cpu(data.d32) & 0xFFFFFF) - 0x800000;
 597
 598                 switch (chan->type) {
 599                 case IIO_TEMP:
 600                 /* temperature in milli degrees Celsius
 601                  * T = ((*val / 2048) - 4096) * 1000
 602                  */
 603                         *val = (*val * 125) / 256;
 604                         break;
 605                 case IIO_VOLTAGE:
 606                         if (chan->channel == 1) /* supply_raw*/
 607                                 *val = *val * 6;
 608                         break;
 609                 default:
 610                         break;
 611                 }
 612
 613                 ret = IIO_VAL_INT;
 614                 break;
 615         case IIO_CHAN_INFO_CALIBSCALE:
 616                 switch (chan->type) {
 617                 case IIO_CAPACITANCE:
 618                         reg = AD7746_REG_CAP_GAINH;
 619                         break;
 620                 case IIO_VOLTAGE:
 621                         reg = AD7746_REG_VOLT_GAINH;
 622                         break;
 623                 default:
 624                         ret = -EINVAL;
 625                         goto out;
 626                 }
 627
 628                 ret = i2c_smbus_read_word_data(chip->client, reg);
 629                 if (ret < 0)
 630                         goto out;
 631                 /* 1 + gain_val / 2^16 */
 632                 *val = 1;
 633                 *val2 = (15625 * swab16(ret)) / 1024;
 634
 635                 ret = IIO_VAL_INT_PLUS_MICRO;
 636                 break;
 637         case IIO_CHAN_INFO_CALIBBIAS:
 638                 ret = i2c_smbus_read_word_data(chip->client,
 639                                                AD7746_REG_CAP_OFFH);
 640                 if (ret < 0)
 641                         goto out;
 642                 *val = swab16(ret);
 643
 644                 ret = IIO_VAL_INT;
 645                 break;
 646         case IIO_CHAN_INFO_OFFSET:
 647                 *val = AD7746_CAPDAC_DACP(chip->capdac[chan->channel]
 648                         [chan->differential]) * 338646;
 649
 650                 ret = IIO_VAL_INT;
 651                 break;
 652         case IIO_CHAN_INFO_SCALE:
 653                 switch (chan->type) {
 654                 case IIO_CAPACITANCE:
 655                         /* 8.192pf / 2^24 */
 656                         *val2 = 488;
 657                         *val =  0;
 658                         break;
 659                 case IIO_VOLTAGE:
 660                         /* 1170mV / 2^23 */
 661                         *val2 = 139475;
 662                         *val =  0;
 663                         break;
 664                 default:
 665                         ret =  -EINVAL;
 666                         goto out;
 667                 }
 668
 669                 ret = IIO_VAL_INT_PLUS_NANO;
 670                 break;
 671         default:
 672                 ret = -EINVAL;
 673         };
 674 out:
 675         mutex_unlock(&indio_dev->mlock);
 676         return ret;
 677 }
 678
 679 static const struct iio_info ad7746_info = {
 680         .attrs = &ad7746_attribute_group,
 681         .read_raw = &ad7746_read_raw,
 682         .write_raw = &ad7746_write_raw,
 683         .driver_module = THIS_MODULE,
 684 };
 685
 686 /*
 687  * device probe and remove
 688  */
 689
 690 static int __devinit ad7746_probe(struct i2c_client *client,
 691                 const struct i2c_device_id *id)
 692 {
 693         struct ad7746_platform_data *pdata = client->dev.platform_data;
 694         struct ad7746_chip_info *chip;
 695         struct iio_dev *indio_dev;
 696         int ret = 0;
 697         unsigned char regval = 0;
 698
 699         indio_dev = iio_allocate_device(sizeof(*chip));
 700         if (indio_dev == NULL) {
 701                 ret = -ENOMEM;
 702                 goto error_ret;
 703         }
 704         chip = iio_priv(indio_dev);
 705         /* this is only used for device removal purposes */
 706         i2c_set_clientdata(client, indio_dev);
 707
 708         chip->client = client;
 709         chip->capdac_set = -1;
 710
 711         /* Establish that the iio_dev is a child of the i2c device */
 712         indio_dev->name = id->name;
 713         indio_dev->dev.parent = &client->dev;
 714         indio_dev->info = &ad7746_info;
 715         indio_dev->channels = ad7746_channels;
 716         if (id->driver_data == 7746)
 717                 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 718         else
 719                 indio_dev->num_channels =  ARRAY_SIZE(ad7746_channels) - 2;
 720         indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 721         indio_dev->modes = INDIO_DIRECT_MODE;
 722
 723         if (pdata) {
 724                 if (pdata->exca_en) {
 725                         if (pdata->exca_inv_en)
 726                                 regval |= AD7746_EXCSETUP_NEXCA;
 727                         else
 728                                 regval |= AD7746_EXCSETUP_EXCA;
 729                 }
 730
 731                 if (pdata->excb_en) {
 732                         if (pdata->excb_inv_en)
 733                                 regval |= AD7746_EXCSETUP_NEXCB;
 734                         else
 735                                 regval |= AD7746_EXCSETUP_EXCB;
 736                 }
 737
 738                 regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
 739         } else {
 740                 dev_warn(&client->dev, "No platform data? using default\n");
 741                 regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
 742                         AD7746_EXCSETUP_EXCLVL(3);
 743         }
 744
 745         ret = i2c_smbus_write_byte_data(chip->client,
 746                                         AD7746_REG_EXC_SETUP, regval);
 747         if (ret < 0)
 748                 goto error_free_dev;
 749
 750         ret = iio_device_register(indio_dev);
 751         if (ret)
 752                 goto error_free_dev;
 753
 754         dev_info(&client->dev, "%s capacitive sensor registered\n", id->name);
 755
 756         return 0;
 757
 758 error_free_dev:
 759         iio_free_device(indio_dev);
 760 error_ret:
 761         return ret;
 762 }
 763
 764 static int __devexit ad7746_remove(struct i2c_client *client)
 765 {
 766         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 767
 768         iio_device_unregister(indio_dev);
 769         iio_free_device(indio_dev);
 770
 771         return 0;
 772 }
 773
 774 static const struct i2c_device_id ad7746_id[] = {
 775         { "ad7745", 7745 },
 776         { "ad7746", 7746 },
 777         { "ad7747", 7747 },
 778         {}
 779 };
 780
 781 MODULE_DEVICE_TABLE(i2c, ad7746_id);
 782
 783 static struct i2c_driver ad7746_driver = {
 784         .driver = {
 785                 .name = KBUILD_MODNAME,
 786         },
 787         .probe = ad7746_probe,
 788         .remove = __devexit_p(ad7746_remove),
 789         .id_table = ad7746_id,
 790 };
 791 module_i2c_driver(ad7746_driver);
 792
 793 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 794 MODULE_DESCRIPTION("Analog Devices AD7746/5/7 capacitive sensor driver");
 795 MODULE_LICENSE("GPL v2");