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 <linux/iio/iio.h>
  20 #include <linux/iio/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 specific 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         union {
 110                 __be32 d32;
 111                 u8 d8[4];
 112         } data ____cacheline_aligned;
 113 };
 114
 115 enum ad7746_chan {
 116         VIN,
 117         VIN_VDD,
 118         TEMP_INT,
 119         TEMP_EXT,
 120         CIN1,
 121         CIN1_DIFF,
 122         CIN2,
 123         CIN2_DIFF,
 124 };
 125
 126 static const struct iio_chan_spec ad7746_channels[] = {
 127         [VIN] = {
 128                 .type = IIO_VOLTAGE,
 129                 .indexed = 1,
 130                 .channel = 0,
 131                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 132                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 133                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 134                         AD7746_VTSETUP_VTMD_EXT_VIN,
 135         },
 136         [VIN_VDD] = {
 137                 .type = IIO_VOLTAGE,
 138                 .indexed = 1,
 139                 .channel = 1,
 140                 .extend_name = "supply",
 141                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 142                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 143                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 144                         AD7746_VTSETUP_VTMD_VDD_MON,
 145         },
 146         [TEMP_INT] = {
 147                 .type = IIO_TEMP,
 148                 .indexed = 1,
 149                 .channel = 0,
 150                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 151                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 152                         AD7746_VTSETUP_VTMD_INT_TEMP,
 153         },
 154         [TEMP_EXT] = {
 155                 .type = IIO_TEMP,
 156                 .indexed = 1,
 157                 .channel = 1,
 158                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 159                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 160                         AD7746_VTSETUP_VTMD_EXT_TEMP,
 161         },
 162         [CIN1] = {
 163                 .type = IIO_CAPACITANCE,
 164                 .indexed = 1,
 165                 .channel = 0,
 166                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 167                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 168                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 169                 BIT(IIO_CHAN_INFO_SCALE),
 170                 .address = AD7746_REG_CAP_DATA_HIGH << 8,
 171         },
 172         [CIN1_DIFF] = {
 173                 .type = IIO_CAPACITANCE,
 174                 .differential = 1,
 175                 .indexed = 1,
 176                 .channel = 0,
 177                 .channel2 = 2,
 178                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 179                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 180                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 181                 BIT(IIO_CHAN_INFO_SCALE),
 182                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 183                         AD7746_CAPSETUP_CAPDIFF
 184         },
 185         [CIN2] = {
 186                 .type = IIO_CAPACITANCE,
 187                 .indexed = 1,
 188                 .channel = 1,
 189                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 190                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 191                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 192                 BIT(IIO_CHAN_INFO_SCALE),
 193                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 194                         AD7746_CAPSETUP_CIN2,
 195         },
 196         [CIN2_DIFF] = {
 197                 .type = IIO_CAPACITANCE,
 198                 .differential = 1,
 199                 .indexed = 1,
 200                 .channel = 1,
 201                 .channel2 = 3,
 202                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 203                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 204                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 205                 BIT(IIO_CHAN_INFO_SCALE),
 206                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 207                         AD7746_CAPSETUP_CAPDIFF | AD7746_CAPSETUP_CIN2,
 208         }
 209 };
 210
 211 /* Values are Update Rate (Hz), Conversion Time (ms) + 1*/
 212 static const unsigned char ad7746_vt_filter_rate_table[][2] = {
 213         {50, 20 + 1}, {31, 32 + 1}, {16, 62 + 1}, {8, 122 + 1},
 214 };
 215
 216 static const unsigned char ad7746_cap_filter_rate_table[][2] = {
 217         {91, 11 + 1}, {84, 12 + 1}, {50, 20 + 1}, {26, 38 + 1},
 218         {16, 62 + 1}, {13, 77 + 1}, {11, 92 + 1}, {9, 110 + 1},
 219 };
 220
 221 static int ad7746_select_channel(struct iio_dev *indio_dev,
 222                             struct iio_chan_spec const *chan)
 223 {
 224         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 225         int ret, delay;
 226         u8 vt_setup, cap_setup;
 227
 228         switch (chan->type) {
 229         case IIO_CAPACITANCE:
 230                 cap_setup = (chan->address & 0xFF) | AD7746_CAPSETUP_CAPEN;
 231                 vt_setup = chip->vt_setup & ~AD7746_VTSETUP_VTEN;
 232                 delay = ad7746_cap_filter_rate_table[(chip->config >> 3) &
 233                         0x7][1];
 234
 235                 if (chip->capdac_set != chan->channel) {
 236                         ret = i2c_smbus_write_byte_data(chip->client,
 237                                 AD7746_REG_CAPDACA,
 238                                 chip->capdac[chan->channel][0]);
 239                         if (ret < 0)
 240                                 return ret;
 241                         ret = i2c_smbus_write_byte_data(chip->client,
 242                                 AD7746_REG_CAPDACB,
 243                                 chip->capdac[chan->channel][1]);
 244                         if (ret < 0)
 245                                 return ret;
 246
 247                         chip->capdac_set = chan->channel;
 248                 }
 249                 break;
 250         case IIO_VOLTAGE:
 251         case IIO_TEMP:
 252                 vt_setup = (chan->address & 0xFF) | AD7746_VTSETUP_VTEN;
 253                 cap_setup = chip->cap_setup & ~AD7746_CAPSETUP_CAPEN;
 254                 delay = ad7746_cap_filter_rate_table[(chip->config >> 6) &
 255                         0x3][1];
 256                 break;
 257         default:
 258                 return -EINVAL;
 259         }
 260
 261         if (chip->cap_setup != cap_setup) {
 262                 ret = i2c_smbus_write_byte_data(chip->client,
 263                                                 AD7746_REG_CAP_SETUP,
 264                                                 cap_setup);
 265                 if (ret < 0)
 266                         return ret;
 267
 268                 chip->cap_setup = cap_setup;
 269         }
 270
 271         if (chip->vt_setup != vt_setup) {
 272                 ret = i2c_smbus_write_byte_data(chip->client,
 273                                                 AD7746_REG_VT_SETUP,
 274                                                 vt_setup);
 275                 if (ret < 0)
 276                         return ret;
 277
 278                 chip->vt_setup = vt_setup;
 279         }
 280
 281         return delay;
 282 }
 283
 284 static inline ssize_t ad7746_start_calib(struct device *dev,
 285                                          struct device_attribute *attr,
 286                                          const char *buf,
 287                                          size_t len,
 288                                          u8 regval)
 289 {
 290         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 291         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 292         bool doit;
 293         int ret, timeout = 10;
 294
 295         ret = strtobool(buf, &doit);
 296         if (ret < 0)
 297                 return ret;
 298
 299         if (!doit)
 300                 return 0;
 301
 302         mutex_lock(&indio_dev->mlock);
 303         regval |= chip->config;
 304         ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG, regval);
 305         if (ret < 0) {
 306                 mutex_unlock(&indio_dev->mlock);
 307                 return ret;
 308         }
 309
 310         do {
 311                 msleep(20);
 312                 ret = i2c_smbus_read_byte_data(chip->client, AD7746_REG_CFG);
 313                 if (ret < 0) {
 314                         mutex_unlock(&indio_dev->mlock);
 315                         return ret;
 316                 }
 317         } while ((ret == regval) && timeout--);
 318
 319         mutex_unlock(&indio_dev->mlock);
 320
 321         return len;
 322 }
 323
 324 static ssize_t ad7746_start_offset_calib(struct device *dev,
 325                                          struct device_attribute *attr,
 326                                          const char *buf,
 327                                          size_t len)
 328 {
 329         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 330         int ret = ad7746_select_channel(indio_dev,
 331                               &ad7746_channels[to_iio_dev_attr(attr)->address]);
 332         if (ret < 0)
 333                 return ret;
 334
 335         return ad7746_start_calib(dev, attr, buf, len,
 336                                   AD7746_CONF_MODE_OFFS_CAL);
 337 }
 338
 339 static ssize_t ad7746_start_gain_calib(struct device *dev,
 340                                        struct device_attribute *attr,
 341                                        const char *buf,
 342                                        size_t len)
 343 {
 344         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 345         int ret = ad7746_select_channel(indio_dev,
 346                               &ad7746_channels[to_iio_dev_attr(attr)->address]);
 347         if (ret < 0)
 348                 return ret;
 349
 350         return ad7746_start_calib(dev, attr, buf, len,
 351                                   AD7746_CONF_MODE_GAIN_CAL);
 352 }
 353
 354 static IIO_DEVICE_ATTR(in_capacitance0_calibbias_calibration,
 355                        S_IWUSR, NULL, ad7746_start_offset_calib, CIN1);
 356 static IIO_DEVICE_ATTR(in_capacitance1_calibbias_calibration,
 357                        S_IWUSR, NULL, ad7746_start_offset_calib, CIN2);
 358 static IIO_DEVICE_ATTR(in_capacitance0_calibscale_calibration,
 359                        S_IWUSR, NULL, ad7746_start_gain_calib, CIN1);
 360 static IIO_DEVICE_ATTR(in_capacitance1_calibscale_calibration,
 361                        S_IWUSR, NULL, ad7746_start_gain_calib, CIN2);
 362 static IIO_DEVICE_ATTR(in_voltage0_calibscale_calibration,
 363                        S_IWUSR, NULL, ad7746_start_gain_calib, VIN);
 364
 365 static ssize_t ad7746_show_cap_filter_rate_setup(struct device *dev,
 366                 struct device_attribute *attr,
 367                 char *buf)
 368 {
 369         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 370         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 371
 372         return sprintf(buf, "%d\n", ad7746_cap_filter_rate_table[
 373                         (chip->config >> 3) & 0x7][0]);
 374 }
 375
 376 static ssize_t ad7746_store_cap_filter_rate_setup(struct device *dev,
 377                 struct device_attribute *attr,
 378                 const char *buf,
 379                 size_t len)
 380 {
 381         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 382         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 383         u8 data;
 384         int ret, i;
 385
 386         ret = kstrtou8(buf, 10, &data);
 387         if (ret < 0)
 388                 return ret;
 389
 390         for (i = 0; i < ARRAY_SIZE(ad7746_cap_filter_rate_table); i++)
 391                 if (data >= ad7746_cap_filter_rate_table[i][0])
 392                         break;
 393
 394         if (i >= ARRAY_SIZE(ad7746_cap_filter_rate_table))
 395                 i = ARRAY_SIZE(ad7746_cap_filter_rate_table) - 1;
 396
 397         mutex_lock(&indio_dev->mlock);
 398         chip->config &= ~AD7746_CONF_CAPFS(0x7);
 399         chip->config |= AD7746_CONF_CAPFS(i);
 400         mutex_unlock(&indio_dev->mlock);
 401
 402         return len;
 403 }
 404
 405 static ssize_t ad7746_show_vt_filter_rate_setup(struct device *dev,
 406                 struct device_attribute *attr,
 407                 char *buf)
 408 {
 409         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 410         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 411
 412         return sprintf(buf, "%d\n", ad7746_vt_filter_rate_table[
 413                         (chip->config >> 6) & 0x3][0]);
 414 }
 415
 416 static ssize_t ad7746_store_vt_filter_rate_setup(struct device *dev,
 417                 struct device_attribute *attr,
 418                 const char *buf,
 419                 size_t len)
 420 {
 421         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 422         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 423         u8 data;
 424         int ret, i;
 425
 426         ret = kstrtou8(buf, 10, &data);
 427         if (ret < 0)
 428                 return ret;
 429
 430         for (i = 0; i < ARRAY_SIZE(ad7746_vt_filter_rate_table); i++)
 431                 if (data >= ad7746_vt_filter_rate_table[i][0])
 432                         break;
 433
 434         if (i >= ARRAY_SIZE(ad7746_vt_filter_rate_table))
 435                 i = ARRAY_SIZE(ad7746_vt_filter_rate_table) - 1;
 436
 437         mutex_lock(&indio_dev->mlock);
 438         chip->config &= ~AD7746_CONF_VTFS(0x3);
 439         chip->config |= AD7746_CONF_VTFS(i);
 440         mutex_unlock(&indio_dev->mlock);
 441
 442         return len;
 443 }
 444
 445 static IIO_DEVICE_ATTR(in_capacitance_sampling_frequency,
 446                        S_IRUGO | S_IWUSR, ad7746_show_cap_filter_rate_setup,
 447                         ad7746_store_cap_filter_rate_setup, 0);
 448
 449 static IIO_DEVICE_ATTR(in_voltage_sampling_frequency,
 450                        S_IRUGO | S_IWUSR, ad7746_show_vt_filter_rate_setup,
 451                        ad7746_store_vt_filter_rate_setup, 0);
 452
 453 static IIO_CONST_ATTR(in_voltage_sampling_frequency_available, "50 31 16 8");
 454 static IIO_CONST_ATTR(in_capacitance_sampling_frequency_available,
 455                        "91 84 50 26 16 13 11 9");
 456
 457 static struct attribute *ad7746_attributes[] = {
 458         &iio_dev_attr_in_capacitance_sampling_frequency.dev_attr.attr,
 459         &iio_dev_attr_in_voltage_sampling_frequency.dev_attr.attr,
 460         &iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
 461         &iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
 462         &iio_dev_attr_in_capacitance1_calibscale_calibration.dev_attr.attr,
 463         &iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
 464         &iio_dev_attr_in_voltage0_calibscale_calibration.dev_attr.attr,
 465         &iio_const_attr_in_voltage_sampling_frequency_available.dev_attr.attr,
 466         &iio_const_attr_in_capacitance_sampling_frequency_available.
 467         dev_attr.attr,
 468         NULL,
 469 };
 470
 471 static const struct attribute_group ad7746_attribute_group = {
 472         .attrs = ad7746_attributes,
 473 };
 474
 475 static int ad7746_write_raw(struct iio_dev *indio_dev,
 476                             struct iio_chan_spec const *chan,
 477                             int val,
 478                             int val2,
 479                             long mask)
 480 {
 481         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 482         int ret, reg;
 483
 484         mutex_lock(&indio_dev->mlock);
 485
 486         switch (mask) {
 487         case IIO_CHAN_INFO_CALIBSCALE:
 488                 if (val != 1) {
 489                         ret = -EINVAL;
 490                         goto out;
 491                 }
 492
 493                 val = (val2 * 1024) / 15625;
 494
 495                 switch (chan->type) {
 496                 case IIO_CAPACITANCE:
 497                         reg = AD7746_REG_CAP_GAINH;
 498                         break;
 499                 case IIO_VOLTAGE:
 500                         reg = AD7746_REG_VOLT_GAINH;
 501                         break;
 502                 default:
 503                         ret = -EINVAL;
 504                         goto out;
 505                 }
 506
 507                 ret = i2c_smbus_write_word_data(chip->client, reg, swab16(val));
 508                 if (ret < 0)
 509                         goto out;
 510
 511                 ret = 0;
 512                 break;
 513         case IIO_CHAN_INFO_CALIBBIAS:
 514                 if ((val < 0) | (val > 0xFFFF)) {
 515                         ret = -EINVAL;
 516                         goto out;
 517                 }
 518                 ret = i2c_smbus_write_word_data(chip->client,
 519                                 AD7746_REG_CAP_OFFH, swab16(val));
 520                 if (ret < 0)
 521                         goto out;
 522
 523                 ret = 0;
 524                 break;
 525         case IIO_CHAN_INFO_OFFSET:
 526                 if ((val < 0) | (val > 43008000)) { /* 21pF */
 527                         ret = -EINVAL;
 528                         goto out;
 529                 }
 530
 531                 /* CAPDAC Scale = 21pF_typ / 127
 532                  * CIN Scale = 8.192pF / 2^24
 533                  * Offset Scale = CAPDAC Scale / CIN Scale = 338646
 534                  * */
 535
 536                 val /= 338646;
 537
 538                 chip->capdac[chan->channel][chan->differential] = (val > 0 ?
 539                         AD7746_CAPDAC_DACP(val) | AD7746_CAPDAC_DACEN : 0);
 540
 541                 ret = i2c_smbus_write_byte_data(chip->client,
 542                         AD7746_REG_CAPDACA,
 543                         chip->capdac[chan->channel][0]);
 544                 if (ret < 0)
 545                         goto out;
 546                 ret = i2c_smbus_write_byte_data(chip->client,
 547                         AD7746_REG_CAPDACB,
 548                         chip->capdac[chan->channel][1]);
 549                 if (ret < 0)
 550                         goto out;
 551
 552                 chip->capdac_set = chan->channel;
 553
 554                 ret = 0;
 555                 break;
 556         default:
 557                 ret = -EINVAL;
 558         }
 559
 560 out:
 561         mutex_unlock(&indio_dev->mlock);
 562         return ret;
 563 }
 564
 565 static int ad7746_read_raw(struct iio_dev *indio_dev,
 566                            struct iio_chan_spec const *chan,
 567                            int *val, int *val2,
 568                            long mask)
 569 {
 570         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 571         int ret, delay;
 572         u8 regval, reg;
 573
 574         mutex_lock(&indio_dev->mlock);
 575
 576         switch (mask) {
 577         case IIO_CHAN_INFO_RAW:
 578         case IIO_CHAN_INFO_PROCESSED:
 579                 ret = ad7746_select_channel(indio_dev, chan);
 580                 if (ret < 0)
 581                         goto out;
 582                 delay = ret;
 583
 584                 regval = chip->config | AD7746_CONF_MODE_SINGLE_CONV;
 585                 ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG,
 586                                 regval);
 587                 if (ret < 0)
 588                         goto out;
 589
 590                 msleep(delay);
 591                 /* Now read the actual register */
 592
 593                 ret = i2c_smbus_read_i2c_block_data(chip->client,
 594                         chan->address >> 8, 3, &chip->data.d8[1]);
 595
 596                 if (ret < 0)
 597                         goto out;
 598
 599                 *val = (be32_to_cpu(chip->data.d32) & 0xFFFFFF) - 0x800000;
 600
 601                 switch (chan->type) {
 602                 case IIO_TEMP:
 603                 /* temperature in milli degrees Celsius
 604                  * T = ((*val / 2048) - 4096) * 1000
 605                  */
 606                         *val = (*val * 125) / 256;
 607                         break;
 608                 case IIO_VOLTAGE:
 609                         if (chan->channel == 1) /* supply_raw*/
 610                                 *val = *val * 6;
 611                         break;
 612                 default:
 613                         break;
 614                 }
 615
 616                 ret = IIO_VAL_INT;
 617                 break;
 618         case IIO_CHAN_INFO_CALIBSCALE:
 619                 switch (chan->type) {
 620                 case IIO_CAPACITANCE:
 621                         reg = AD7746_REG_CAP_GAINH;
 622                         break;
 623                 case IIO_VOLTAGE:
 624                         reg = AD7746_REG_VOLT_GAINH;
 625                         break;
 626                 default:
 627                         ret = -EINVAL;
 628                         goto out;
 629                 }
 630
 631                 ret = i2c_smbus_read_word_data(chip->client, reg);
 632                 if (ret < 0)
 633                         goto out;
 634                 /* 1 + gain_val / 2^16 */
 635                 *val = 1;
 636                 *val2 = (15625 * swab16(ret)) / 1024;
 637
 638                 ret = IIO_VAL_INT_PLUS_MICRO;
 639                 break;
 640         case IIO_CHAN_INFO_CALIBBIAS:
 641                 ret = i2c_smbus_read_word_data(chip->client,
 642                                                AD7746_REG_CAP_OFFH);
 643                 if (ret < 0)
 644                         goto out;
 645                 *val = swab16(ret);
 646
 647                 ret = IIO_VAL_INT;
 648                 break;
 649         case IIO_CHAN_INFO_OFFSET:
 650                 *val = AD7746_CAPDAC_DACP(chip->capdac[chan->channel]
 651                         [chan->differential]) * 338646;
 652
 653                 ret = IIO_VAL_INT;
 654                 break;
 655         case IIO_CHAN_INFO_SCALE:
 656                 switch (chan->type) {
 657                 case IIO_CAPACITANCE:
 658                         /* 8.192pf / 2^24 */
 659                         *val =  0;
 660                         *val2 = 488;
 661                         ret = IIO_VAL_INT_PLUS_NANO;
 662                         break;
 663                 case IIO_VOLTAGE:
 664                         /* 1170mV / 2^23 */
 665                         *val = 1170;
 666                         *val2 = 23;
 667                         ret = IIO_VAL_FRACTIONAL_LOG2;
 668                         break;
 669                 default:
 670                         ret = -EINVAL;
 671                         break;
 672                 }
 673
 674                 break;
 675         default:
 676                 ret = -EINVAL;
 677         }
 678 out:
 679         mutex_unlock(&indio_dev->mlock);
 680         return ret;
 681 }
 682
 683 static const struct iio_info ad7746_info = {
 684         .attrs = &ad7746_attribute_group,
 685         .read_raw = &ad7746_read_raw,
 686         .write_raw = &ad7746_write_raw,
 687         .driver_module = THIS_MODULE,
 688 };
 689
 690 /*
 691  * device probe and remove
 692  */
 693
 694 static int ad7746_probe(struct i2c_client *client,
 695                 const struct i2c_device_id *id)
 696 {
 697         struct ad7746_platform_data *pdata = client->dev.platform_data;
 698         struct ad7746_chip_info *chip;
 699         struct iio_dev *indio_dev;
 700         int ret = 0;
 701         unsigned char regval = 0;
 702
 703         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 704         if (!indio_dev)
 705                 return -ENOMEM;
 706         chip = iio_priv(indio_dev);
 707         /* this is only used for device removal purposes */
 708         i2c_set_clientdata(client, indio_dev);
 709
 710         chip->client = client;
 711         chip->capdac_set = -1;
 712
 713         /* Establish that the iio_dev is a child of the i2c device */
 714         indio_dev->name = id->name;
 715         indio_dev->dev.parent = &client->dev;
 716         indio_dev->info = &ad7746_info;
 717         indio_dev->channels = ad7746_channels;
 718         if (id->driver_data == 7746)
 719                 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 720         else
 721                 indio_dev->num_channels =  ARRAY_SIZE(ad7746_channels) - 2;
 722         indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 723         indio_dev->modes = INDIO_DIRECT_MODE;
 724
 725         if (pdata) {
 726                 if (pdata->exca_en) {
 727                         if (pdata->exca_inv_en)
 728                                 regval |= AD7746_EXCSETUP_NEXCA;
 729                         else
 730                                 regval |= AD7746_EXCSETUP_EXCA;
 731                 }
 732
 733                 if (pdata->excb_en) {
 734                         if (pdata->excb_inv_en)
 735                                 regval |= AD7746_EXCSETUP_NEXCB;
 736                         else
 737                                 regval |= AD7746_EXCSETUP_EXCB;
 738                 }
 739
 740                 regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
 741         } else {
 742                 dev_warn(&client->dev, "No platform data? using default\n");
 743                 regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
 744                         AD7746_EXCSETUP_EXCLVL(3);
 745         }
 746
 747         ret = i2c_smbus_write_byte_data(chip->client,
 748                                         AD7746_REG_EXC_SETUP, regval);
 749         if (ret < 0)
 750                 return ret;
 751
 752         ret = iio_device_register(indio_dev);
 753         if (ret)
 754                 return ret;
 755
 756         dev_info(&client->dev, "%s capacitive sensor registered\n", id->name);
 757
 758         return 0;
 759 }
 760
 761 static int ad7746_remove(struct i2c_client *client)
 762 {
 763         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 764
 765         iio_device_unregister(indio_dev);
 766
 767         return 0;
 768 }
 769
 770 static const struct i2c_device_id ad7746_id[] = {
 771         { "ad7745", 7745 },
 772         { "ad7746", 7746 },
 773         { "ad7747", 7747 },
 774         {}
 775 };
 776
 777 MODULE_DEVICE_TABLE(i2c, ad7746_id);
 778
 779 static struct i2c_driver ad7746_driver = {
 780         .driver = {
 781                 .name = KBUILD_MODNAME,
 782         },
 783         .probe = ad7746_probe,
 784         .remove = ad7746_remove,
 785         .id_table = ad7746_id,
 786 };
 787 module_i2c_driver(ad7746_driver);
 788
 789 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 790 MODULE_DESCRIPTION("Analog Devices AD7746/5/7 capacitive sensor driver");
 791 MODULE_LICENSE("GPL v2");