drivers/staging/iio/cdc/ad7746.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/device.h>
  10 #include <linux/i2c.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/stat.h>
  16 #include <linux/sysfs.h>
  17
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/sysfs.h>
  20
  21 #include "ad7746.h"
  22
  23 /*
  24  * AD7746 Register Definition
  25  */
  26
  27 #define AD7746_REG_STATUS               0
  28 #define AD7746_REG_CAP_DATA_HIGH        1
  29 #define AD7746_REG_VT_DATA_HIGH         4
  30 #define AD7746_REG_CAP_SETUP            7
  31 #define AD7746_REG_VT_SETUP             8
  32 #define AD7746_REG_EXC_SETUP            9
  33 #define AD7746_REG_CFG                  10
  34 #define AD7746_REG_CAPDACA              11
  35 #define AD7746_REG_CAPDACB              12
  36 #define AD7746_REG_CAP_OFFH             13
  37 #define AD7746_REG_CAP_GAINH            15
  38 #define AD7746_REG_VOLT_GAINH           17
  39
  40 /* Status Register Bit Designations (AD7746_REG_STATUS) */
  41 #define AD7746_STATUS_EXCERR            BIT(3)
  42 #define AD7746_STATUS_RDY               BIT(2)
  43 #define AD7746_STATUS_RDYVT             BIT(1)
  44 #define AD7746_STATUS_RDYCAP            BIT(0)
  45
  46 /* Capacitive Channel Setup Register Bit Designations (AD7746_REG_CAP_SETUP) */
  47 #define AD7746_CAPSETUP_CAPEN           BIT(7)
  48 #define AD7746_CAPSETUP_CIN2            BIT(6) /* AD7746 only */
  49 #define AD7746_CAPSETUP_CAPDIFF         BIT(5)
  50 #define AD7746_CAPSETUP_CACHOP          BIT(0)
  51
  52 /* Voltage/Temperature Setup Register Bit Designations (AD7746_REG_VT_SETUP) */
  53 #define AD7746_VTSETUP_VTEN             (1 << 7)
  54 #define AD7746_VTSETUP_VTMD_INT_TEMP    (0 << 5)
  55 #define AD7746_VTSETUP_VTMD_EXT_TEMP    (1 << 5)
  56 #define AD7746_VTSETUP_VTMD_VDD_MON     (2 << 5)
  57 #define AD7746_VTSETUP_VTMD_EXT_VIN     (3 << 5)
  58 #define AD7746_VTSETUP_EXTREF           BIT(4)
  59 #define AD7746_VTSETUP_VTSHORT          BIT(1)
  60 #define AD7746_VTSETUP_VTCHOP           BIT(0)
  61
  62 /* Excitation Setup Register Bit Designations (AD7746_REG_EXC_SETUP) */
  63 #define AD7746_EXCSETUP_CLKCTRL         BIT(7)
  64 #define AD7746_EXCSETUP_EXCON           BIT(6)
  65 #define AD7746_EXCSETUP_EXCB            BIT(5)
  66 #define AD7746_EXCSETUP_NEXCB           BIT(4)
  67 #define AD7746_EXCSETUP_EXCA            BIT(3)
  68 #define AD7746_EXCSETUP_NEXCA           BIT(2)
  69 #define AD7746_EXCSETUP_EXCLVL(x)       (((x) & 0x3) << 0)
  70
  71 /* Config Register Bit Designations (AD7746_REG_CFG) */
  72 #define AD7746_CONF_VTFS_SHIFT          6
  73 #define AD7746_CONF_CAPFS_SHIFT         3
  74 #define AD7746_CONF_VTFS_MASK           GENMASK(7, 6)
  75 #define AD7746_CONF_CAPFS_MASK          GENMASK(5, 3)
  76 #define AD7746_CONF_MODE_IDLE           (0 << 0)
  77 #define AD7746_CONF_MODE_CONT_CONV      (1 << 0)
  78 #define AD7746_CONF_MODE_SINGLE_CONV    (2 << 0)
  79 #define AD7746_CONF_MODE_PWRDN          (3 << 0)
  80 #define AD7746_CONF_MODE_OFFS_CAL       (5 << 0)
  81 #define AD7746_CONF_MODE_GAIN_CAL       (6 << 0)
  82
  83 /* CAPDAC Register Bit Designations (AD7746_REG_CAPDACx) */
  84 #define AD7746_CAPDAC_DACEN             BIT(7)
  85 #define AD7746_CAPDAC_DACP(x)           ((x) & 0x7F)
  86
  87 /*
  88  * struct ad7746_chip_info - chip specific information
  89  */
  90
  91 struct ad7746_chip_info {
  92         struct i2c_client *client;
  93         struct mutex lock; /* protect sensor state */
  94         /*
  95          * Capacitive channel digital filter setup;
  96          * conversion time/update rate setup per channel
  97          */
  98         u8      config;
  99         u8      cap_setup;
 100         u8      vt_setup;
 101         u8      capdac[2][2];
 102         s8      capdac_set;
 103
 104         union {
 105                 __be32 d32;
 106                 u8 d8[4];
 107         } data ____cacheline_aligned;
 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_separate = BIT(IIO_CHAN_INFO_RAW),
 127                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
 128                         BIT(IIO_CHAN_INFO_SAMP_FREQ),
 129                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 130                         AD7746_VTSETUP_VTMD_EXT_VIN,
 131         },
 132         [VIN_VDD] = {
 133                 .type = IIO_VOLTAGE,
 134                 .indexed = 1,
 135                 .channel = 1,
 136                 .extend_name = "supply",
 137                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 138                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
 139                         BIT(IIO_CHAN_INFO_SAMP_FREQ),
 140                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 141                         AD7746_VTSETUP_VTMD_VDD_MON,
 142         },
 143         [TEMP_INT] = {
 144                 .type = IIO_TEMP,
 145                 .indexed = 1,
 146                 .channel = 0,
 147                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 148                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 149                         AD7746_VTSETUP_VTMD_INT_TEMP,
 150         },
 151         [TEMP_EXT] = {
 152                 .type = IIO_TEMP,
 153                 .indexed = 1,
 154                 .channel = 1,
 155                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 156                 .address = AD7746_REG_VT_DATA_HIGH << 8 |
 157                         AD7746_VTSETUP_VTMD_EXT_TEMP,
 158         },
 159         [CIN1] = {
 160                 .type = IIO_CAPACITANCE,
 161                 .indexed = 1,
 162                 .channel = 0,
 163                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 164                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 165                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 166                 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 167                 .address = AD7746_REG_CAP_DATA_HIGH << 8,
 168         },
 169         [CIN1_DIFF] = {
 170                 .type = IIO_CAPACITANCE,
 171                 .differential = 1,
 172                 .indexed = 1,
 173                 .channel = 0,
 174                 .channel2 = 2,
 175                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 176                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 177                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 178                 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 179                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 180                         AD7746_CAPSETUP_CAPDIFF
 181         },
 182         [CIN2] = {
 183                 .type = IIO_CAPACITANCE,
 184                 .indexed = 1,
 185                 .channel = 1,
 186                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 187                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 188                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 189                 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 190                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 191                         AD7746_CAPSETUP_CIN2,
 192         },
 193         [CIN2_DIFF] = {
 194                 .type = IIO_CAPACITANCE,
 195                 .differential = 1,
 196                 .indexed = 1,
 197                 .channel = 1,
 198                 .channel2 = 3,
 199                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 200                 BIT(IIO_CHAN_INFO_CALIBSCALE) | BIT(IIO_CHAN_INFO_OFFSET),
 201                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBBIAS) |
 202                 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 203                 .address = AD7746_REG_CAP_DATA_HIGH << 8 |
 204                         AD7746_CAPSETUP_CAPDIFF | AD7746_CAPSETUP_CIN2,
 205         }
 206 };
 207
 208 /* Values are Update Rate (Hz), Conversion Time (ms) + 1*/
 209 static const unsigned char ad7746_vt_filter_rate_table[][2] = {
 210         {50, 20 + 1}, {31, 32 + 1}, {16, 62 + 1}, {8, 122 + 1},
 211 };
 212
 213 static const unsigned char ad7746_cap_filter_rate_table[][2] = {
 214         {91, 11 + 1}, {84, 12 + 1}, {50, 20 + 1}, {26, 38 + 1},
 215         {16, 62 + 1}, {13, 77 + 1}, {11, 92 + 1}, {9, 110 + 1},
 216 };
 217
 218 static int ad7746_select_channel(struct iio_dev *indio_dev,
 219                                  struct iio_chan_spec const *chan)
 220 {
 221         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 222         u8 vt_setup, cap_setup;
 223         int ret, delay, idx;
 224
 225         switch (chan->type) {
 226         case IIO_CAPACITANCE:
 227                 cap_setup = (chan->address & 0xFF) | AD7746_CAPSETUP_CAPEN;
 228                 vt_setup = chip->vt_setup & ~AD7746_VTSETUP_VTEN;
 229                 idx = (chip->config & AD7746_CONF_CAPFS_MASK) >>
 230                         AD7746_CONF_CAPFS_SHIFT;
 231                 delay = ad7746_cap_filter_rate_table[idx][1];
 232
 233                 if (chip->capdac_set != chan->channel) {
 234                         ret = i2c_smbus_write_byte_data(chip->client,
 235                                 AD7746_REG_CAPDACA,
 236                                 chip->capdac[chan->channel][0]);
 237                         if (ret < 0)
 238                                 return ret;
 239                         ret = i2c_smbus_write_byte_data(chip->client,
 240                                 AD7746_REG_CAPDACB,
 241                                 chip->capdac[chan->channel][1]);
 242                         if (ret < 0)
 243                                 return ret;
 244
 245                         chip->capdac_set = chan->channel;
 246                 }
 247                 break;
 248         case IIO_VOLTAGE:
 249         case IIO_TEMP:
 250                 vt_setup = (chan->address & 0xFF) | AD7746_VTSETUP_VTEN;
 251                 cap_setup = chip->cap_setup & ~AD7746_CAPSETUP_CAPEN;
 252                 idx = (chip->config & AD7746_CONF_VTFS_MASK) >>
 253                         AD7746_CONF_VTFS_SHIFT;
 254                 delay = ad7746_cap_filter_rate_table[idx][1];
 255                 break;
 256         default:
 257                 return -EINVAL;
 258         }
 259
 260         if (chip->cap_setup != cap_setup) {
 261                 ret = i2c_smbus_write_byte_data(chip->client,
 262                                                 AD7746_REG_CAP_SETUP,
 263                                                 cap_setup);
 264                 if (ret < 0)
 265                         return ret;
 266
 267                 chip->cap_setup = cap_setup;
 268         }
 269
 270         if (chip->vt_setup != vt_setup) {
 271                 ret = i2c_smbus_write_byte_data(chip->client,
 272                                                 AD7746_REG_VT_SETUP,
 273                                                 vt_setup);
 274                 if (ret < 0)
 275                         return ret;
 276
 277                 chip->vt_setup = vt_setup;
 278         }
 279
 280         return delay;
 281 }
 282
 283 static inline ssize_t ad7746_start_calib(struct device *dev,
 284                                          struct device_attribute *attr,
 285                                          const char *buf,
 286                                          size_t len,
 287                                          u8 regval)
 288 {
 289         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 290         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 291         int ret, timeout = 10;
 292         bool doit;
 293
 294         ret = strtobool(buf, &doit);
 295         if (ret < 0)
 296                 return ret;
 297
 298         if (!doit)
 299                 return 0;
 300
 301         mutex_lock(&chip->lock);
 302         regval |= chip->config;
 303         ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG, regval);
 304         if (ret < 0)
 305                 goto unlock;
 306
 307         do {
 308                 msleep(20);
 309                 ret = i2c_smbus_read_byte_data(chip->client, AD7746_REG_CFG);
 310                 if (ret < 0)
 311                         goto unlock;
 312
 313         } while ((ret == regval) && timeout--);
 314
 315         mutex_unlock(&chip->lock);
 316
 317         return len;
 318
 319 unlock:
 320         mutex_unlock(&chip->lock);
 321         return ret;
 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                        0200, NULL, ad7746_start_offset_calib, CIN1);
 356 static IIO_DEVICE_ATTR(in_capacitance1_calibbias_calibration,
 357                        0200, NULL, ad7746_start_offset_calib, CIN2);
 358 static IIO_DEVICE_ATTR(in_capacitance0_calibscale_calibration,
 359                        0200, NULL, ad7746_start_gain_calib, CIN1);
 360 static IIO_DEVICE_ATTR(in_capacitance1_calibscale_calibration,
 361                        0200, NULL, ad7746_start_gain_calib, CIN2);
 362 static IIO_DEVICE_ATTR(in_voltage0_calibscale_calibration,
 363                        0200, NULL, ad7746_start_gain_calib, VIN);
 364
 365 static int ad7746_store_cap_filter_rate_setup(struct ad7746_chip_info *chip,
 366                                               int val)
 367 {
 368         int i;
 369
 370         for (i = 0; i < ARRAY_SIZE(ad7746_cap_filter_rate_table); i++)
 371                 if (val >= ad7746_cap_filter_rate_table[i][0])
 372                         break;
 373
 374         if (i >= ARRAY_SIZE(ad7746_cap_filter_rate_table))
 375                 i = ARRAY_SIZE(ad7746_cap_filter_rate_table) - 1;
 376
 377         chip->config &= ~AD7746_CONF_CAPFS_MASK;
 378         chip->config |= i << AD7746_CONF_CAPFS_SHIFT;
 379
 380         return 0;
 381 }
 382
 383 static int ad7746_store_vt_filter_rate_setup(struct ad7746_chip_info *chip,
 384                                              int val)
 385 {
 386         int i;
 387
 388         for (i = 0; i < ARRAY_SIZE(ad7746_vt_filter_rate_table); i++)
 389                 if (val >= ad7746_vt_filter_rate_table[i][0])
 390                         break;
 391
 392         if (i >= ARRAY_SIZE(ad7746_vt_filter_rate_table))
 393                 i = ARRAY_SIZE(ad7746_vt_filter_rate_table) - 1;
 394
 395         chip->config &= ~AD7746_CONF_VTFS_MASK;
 396         chip->config |= i << AD7746_CONF_VTFS_SHIFT;
 397
 398         return 0;
 399 }
 400
 401 static IIO_CONST_ATTR(in_voltage_sampling_frequency_available, "50 31 16 8");
 402 static IIO_CONST_ATTR(in_capacitance_sampling_frequency_available,
 403                        "91 84 50 26 16 13 11 9");
 404
 405 static struct attribute *ad7746_attributes[] = {
 406         &iio_dev_attr_in_capacitance0_calibbias_calibration.dev_attr.attr,
 407         &iio_dev_attr_in_capacitance0_calibscale_calibration.dev_attr.attr,
 408         &iio_dev_attr_in_capacitance1_calibscale_calibration.dev_attr.attr,
 409         &iio_dev_attr_in_capacitance1_calibbias_calibration.dev_attr.attr,
 410         &iio_dev_attr_in_voltage0_calibscale_calibration.dev_attr.attr,
 411         &iio_const_attr_in_voltage_sampling_frequency_available.dev_attr.attr,
 412         &iio_const_attr_in_capacitance_sampling_frequency_available.dev_attr.attr,
 413         NULL,
 414 };
 415
 416 static const struct attribute_group ad7746_attribute_group = {
 417         .attrs = ad7746_attributes,
 418 };
 419
 420 static int ad7746_write_raw(struct iio_dev *indio_dev,
 421                             struct iio_chan_spec const *chan,
 422                             int val,
 423                             int val2,
 424                             long mask)
 425 {
 426         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 427         int ret, reg;
 428
 429         mutex_lock(&chip->lock);
 430
 431         switch (mask) {
 432         case IIO_CHAN_INFO_CALIBSCALE:
 433                 if (val != 1) {
 434                         ret = -EINVAL;
 435                         goto out;
 436                 }
 437
 438                 val = (val2 * 1024) / 15625;
 439
 440                 switch (chan->type) {
 441                 case IIO_CAPACITANCE:
 442                         reg = AD7746_REG_CAP_GAINH;
 443                         break;
 444                 case IIO_VOLTAGE:
 445                         reg = AD7746_REG_VOLT_GAINH;
 446                         break;
 447                 default:
 448                         ret = -EINVAL;
 449                         goto out;
 450                 }
 451
 452                 ret = i2c_smbus_write_word_swapped(chip->client, reg, val);
 453                 if (ret < 0)
 454                         goto out;
 455
 456                 ret = 0;
 457                 break;
 458         case IIO_CHAN_INFO_CALIBBIAS:
 459                 if (val < 0 || val > 0xFFFF) {
 460                         ret = -EINVAL;
 461                         goto out;
 462                 }
 463                 ret = i2c_smbus_write_word_swapped(chip->client,
 464                                                    AD7746_REG_CAP_OFFH, val);
 465                 if (ret < 0)
 466                         goto out;
 467
 468                 ret = 0;
 469                 break;
 470         case IIO_CHAN_INFO_OFFSET:
 471                 if (val < 0 || val > 43008000) { /* 21pF */
 472                         ret = -EINVAL;
 473                         goto out;
 474                 }
 475
 476                 /*
 477                  * CAPDAC Scale = 21pF_typ / 127
 478                  * CIN Scale = 8.192pF / 2^24
 479                  * Offset Scale = CAPDAC Scale / CIN Scale = 338646
 480                  */
 481
 482                 val /= 338646;
 483
 484                 chip->capdac[chan->channel][chan->differential] = val > 0 ?
 485                         AD7746_CAPDAC_DACP(val) | AD7746_CAPDAC_DACEN : 0;
 486
 487                 ret = i2c_smbus_write_byte_data(chip->client,
 488                                                 AD7746_REG_CAPDACA,
 489                                                 chip->capdac[chan->channel][0]);
 490                 if (ret < 0)
 491                         goto out;
 492                 ret = i2c_smbus_write_byte_data(chip->client,
 493                                                 AD7746_REG_CAPDACB,
 494                                                 chip->capdac[chan->channel][1]);
 495                 if (ret < 0)
 496                         goto out;
 497
 498                 chip->capdac_set = chan->channel;
 499
 500                 ret = 0;
 501                 break;
 502         case IIO_CHAN_INFO_SAMP_FREQ:
 503                 if (val2) {
 504                         ret = -EINVAL;
 505                         goto out;
 506                 }
 507
 508                 switch (chan->type) {
 509                 case IIO_CAPACITANCE:
 510                         ret = ad7746_store_cap_filter_rate_setup(chip, val);
 511                         break;
 512                 case IIO_VOLTAGE:
 513                         ret = ad7746_store_vt_filter_rate_setup(chip, val);
 514                         break;
 515                 default:
 516                         ret = -EINVAL;
 517                 }
 518                 break;
 519         default:
 520                 ret = -EINVAL;
 521         }
 522
 523 out:
 524         mutex_unlock(&chip->lock);
 525         return ret;
 526 }
 527
 528 static int ad7746_read_raw(struct iio_dev *indio_dev,
 529                            struct iio_chan_spec const *chan,
 530                            int *val, int *val2,
 531                            long mask)
 532 {
 533         struct ad7746_chip_info *chip = iio_priv(indio_dev);
 534         int ret, delay, idx;
 535         u8 regval, reg;
 536
 537         mutex_lock(&chip->lock);
 538
 539         switch (mask) {
 540         case IIO_CHAN_INFO_RAW:
 541         case IIO_CHAN_INFO_PROCESSED:
 542                 ret = ad7746_select_channel(indio_dev, chan);
 543                 if (ret < 0)
 544                         goto out;
 545                 delay = ret;
 546
 547                 regval = chip->config | AD7746_CONF_MODE_SINGLE_CONV;
 548                 ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG,
 549                                                 regval);
 550                 if (ret < 0)
 551                         goto out;
 552
 553                 msleep(delay);
 554                 /* Now read the actual register */
 555
 556                 ret = i2c_smbus_read_i2c_block_data(chip->client,
 557                                                     chan->address >> 8, 3,
 558                                                     &chip->data.d8[1]);
 559
 560                 if (ret < 0)
 561                         goto out;
 562
 563                 *val = (be32_to_cpu(chip->data.d32) & 0xFFFFFF) - 0x800000;
 564
 565                 switch (chan->type) {
 566                 case IIO_TEMP:
 567                 /*
 568                  * temperature in milli degrees Celsius
 569                  * T = ((*val / 2048) - 4096) * 1000
 570                  */
 571                         *val = (*val * 125) / 256;
 572                         break;
 573                 case IIO_VOLTAGE:
 574                         if (chan->channel == 1) /* supply_raw*/
 575                                 *val = *val * 6;
 576                         break;
 577                 default:
 578                         break;
 579                 }
 580
 581                 ret = IIO_VAL_INT;
 582                 break;
 583         case IIO_CHAN_INFO_CALIBSCALE:
 584                 switch (chan->type) {
 585                 case IIO_CAPACITANCE:
 586                         reg = AD7746_REG_CAP_GAINH;
 587                         break;
 588                 case IIO_VOLTAGE:
 589                         reg = AD7746_REG_VOLT_GAINH;
 590                         break;
 591                 default:
 592                         ret = -EINVAL;
 593                         goto out;
 594                 }
 595
 596                 ret = i2c_smbus_read_word_swapped(chip->client, reg);
 597                 if (ret < 0)
 598                         goto out;
 599                 /* 1 + gain_val / 2^16 */
 600                 *val = 1;
 601                 *val2 = (15625 * ret) / 1024;
 602
 603                 ret = IIO_VAL_INT_PLUS_MICRO;
 604                 break;
 605         case IIO_CHAN_INFO_CALIBBIAS:
 606                 ret = i2c_smbus_read_word_swapped(chip->client,
 607                                                   AD7746_REG_CAP_OFFH);
 608                 if (ret < 0)
 609                         goto out;
 610                 *val = ret;
 611
 612                 ret = IIO_VAL_INT;
 613                 break;
 614         case IIO_CHAN_INFO_OFFSET:
 615                 *val = AD7746_CAPDAC_DACP(chip->capdac[chan->channel]
 616                                           [chan->differential]) * 338646;
 617
 618                 ret = IIO_VAL_INT;
 619                 break;
 620         case IIO_CHAN_INFO_SCALE:
 621                 switch (chan->type) {
 622                 case IIO_CAPACITANCE:
 623                         /* 8.192pf / 2^24 */
 624                         *val =  0;
 625                         *val2 = 488;
 626                         ret = IIO_VAL_INT_PLUS_NANO;
 627                         break;
 628                 case IIO_VOLTAGE:
 629                         /* 1170mV / 2^23 */
 630                         *val = 1170;
 631                         *val2 = 23;
 632                         ret = IIO_VAL_FRACTIONAL_LOG2;
 633                         break;
 634                 default:
 635                         ret = -EINVAL;
 636                         break;
 637                 }
 638
 639                 break;
 640         case IIO_CHAN_INFO_SAMP_FREQ:
 641                 switch (chan->type) {
 642                 case IIO_CAPACITANCE:
 643                         idx = (chip->config & AD7746_CONF_CAPFS_MASK) >>
 644                                 AD7746_CONF_CAPFS_SHIFT;
 645                         *val = ad7746_cap_filter_rate_table[idx][0];
 646                         ret = IIO_VAL_INT;
 647                         break;
 648                 case IIO_VOLTAGE:
 649                         idx = (chip->config & AD7746_CONF_VTFS_MASK) >>
 650                                 AD7746_CONF_VTFS_SHIFT;
 651                         *val = ad7746_vt_filter_rate_table[idx][0];
 652                         ret = IIO_VAL_INT;
 653                         break;
 654                 default:
 655                         ret = -EINVAL;
 656                 }
 657                 break;
 658         default:
 659                 ret = -EINVAL;
 660         }
 661 out:
 662         mutex_unlock(&chip->lock);
 663         return ret;
 664 }
 665
 666 static const struct iio_info ad7746_info = {
 667         .attrs = &ad7746_attribute_group,
 668         .read_raw = ad7746_read_raw,
 669         .write_raw = ad7746_write_raw,
 670 };
 671
 672 /*
 673  * device probe and remove
 674  */
 675
 676 static int ad7746_probe(struct i2c_client *client,
 677                         const struct i2c_device_id *id)
 678 {
 679         struct ad7746_platform_data *pdata = client->dev.platform_data;
 680         struct ad7746_chip_info *chip;
 681         struct iio_dev *indio_dev;
 682         unsigned char regval = 0;
 683         int ret = 0;
 684
 685         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 686         if (!indio_dev)
 687                 return -ENOMEM;
 688         chip = iio_priv(indio_dev);
 689         mutex_init(&chip->lock);
 690         /* this is only used for device removal purposes */
 691         i2c_set_clientdata(client, indio_dev);
 692
 693         chip->client = client;
 694         chip->capdac_set = -1;
 695
 696         /* Establish that the iio_dev is a child of the i2c device */
 697         indio_dev->name = id->name;
 698         indio_dev->dev.parent = &client->dev;
 699         indio_dev->info = &ad7746_info;
 700         indio_dev->channels = ad7746_channels;
 701         if (id->driver_data == 7746)
 702                 indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 703         else
 704                 indio_dev->num_channels =  ARRAY_SIZE(ad7746_channels) - 2;
 705         indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 706         indio_dev->modes = INDIO_DIRECT_MODE;
 707
 708         if (pdata) {
 709                 if (pdata->exca_en) {
 710                         if (pdata->exca_inv_en)
 711                                 regval |= AD7746_EXCSETUP_NEXCA;
 712                         else
 713                                 regval |= AD7746_EXCSETUP_EXCA;
 714                 }
 715
 716                 if (pdata->excb_en) {
 717                         if (pdata->excb_inv_en)
 718                                 regval |= AD7746_EXCSETUP_NEXCB;
 719                         else
 720                                 regval |= AD7746_EXCSETUP_EXCB;
 721                 }
 722
 723                 regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
 724         } else {
 725                 dev_warn(&client->dev, "No platform data? using default\n");
 726                 regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
 727                         AD7746_EXCSETUP_EXCLVL(3);
 728         }
 729
 730         ret = i2c_smbus_write_byte_data(chip->client,
 731                                         AD7746_REG_EXC_SETUP, regval);
 732         if (ret < 0)
 733                 return ret;
 734
 735         ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
 736         if (ret)
 737                 return ret;
 738
 739         return 0;
 740 }
 741
 742 static const struct i2c_device_id ad7746_id[] = {
 743         { "ad7745", 7745 },
 744         { "ad7746", 7746 },
 745         { "ad7747", 7747 },
 746         {}
 747 };
 748
 749 MODULE_DEVICE_TABLE(i2c, ad7746_id);
 750
 751 static const struct of_device_id ad7746_of_match[] = {
 752         { .compatible = "adi,ad7745" },
 753         { .compatible = "adi,ad7746" },
 754         { .compatible = "adi,ad7747" },
 755         { },
 756 };
 757
 758 MODULE_DEVICE_TABLE(of, ad7746_of_match);
 759
 760 static struct i2c_driver ad7746_driver = {
 761         .driver = {
 762                 .name = KBUILD_MODNAME,
 763                 .of_match_table = ad7746_of_match,
 764         },
 765         .probe = ad7746_probe,
 766         .id_table = ad7746_id,
 767 };
 768 module_i2c_driver(ad7746_driver);
 769
 770 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 771 MODULE_DESCRIPTION("Analog Devices AD7746/5/7 capacitive sensor driver");
 772 MODULE_LICENSE("GPL v2");