drivers/staging/iio/adc/ad7745.c

   1 /*
   2  * AD774X capacitive sensor driver supporting AD7745/6/7
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/gpio.h>
  11 #include <linux/device.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/list.h>
  16 #include <linux/i2c.h>
  17
  18 #include "../iio.h"
  19 #include "../sysfs.h"
  20
  21 /*
  22  * AD774X registers definition
  23  */
  24
  25 #define AD774X_STATUS           0
  26 #define AD774X_STATUS_RDY       (1 << 2)
  27 #define AD774X_STATUS_RDYVT     (1 << 1)
  28 #define AD774X_STATUS_RDYCAP    (1 << 0)
  29 #define AD774X_CAP_DATA_HIGH    1
  30 #define AD774X_CAP_DATA_MID     2
  31 #define AD774X_CAP_DATA_LOW     3
  32 #define AD774X_VT_DATA_HIGH     4
  33 #define AD774X_VT_DATA_MID      5
  34 #define AD774X_VT_DATA_LOW      6
  35 #define AD774X_CAP_SETUP        7
  36 #define AD774X_VT_SETUP         8
  37 #define AD774X_EXEC_SETUP       9
  38 #define AD774X_CFG              10
  39 #define AD774X_CAPDACA          11
  40 #define AD774X_CAPDACB          12
  41 #define AD774X_CAPDAC_EN        (1 << 7)
  42 #define AD774X_CAP_OFFH         13
  43 #define AD774X_CAP_OFFL         14
  44 #define AD774X_CAP_GAINH        15
  45 #define AD774X_CAP_GAINL        16
  46 #define AD774X_VOLT_GAINH       17
  47 #define AD774X_VOLT_GAINL       18
  48
  49 #define AD774X_MAX_CONV_MODE    6
  50
  51 /*
  52  * struct ad774x_chip_info - chip specifc information
  53  */
  54
  55 struct ad774x_chip_info {
  56         struct i2c_client *client;
  57         struct iio_dev *indio_dev;
  58         bool inter;
  59         u16 cap_offs;                   /* Capacitive offset */
  60         u16 cap_gain;                   /* Capacitive gain calibration */
  61         u16 volt_gain;                  /* Voltage gain calibration */
  62         u8  cap_setup;
  63         u8  vt_setup;
  64         u8  exec_setup;
  65
  66         char *conversion_mode;
  67 };
  68
  69 struct ad774x_conversion_mode {
  70         char *name;
  71         u8 reg_cfg;
  72 };
  73
  74 static struct ad774x_conversion_mode
  75 ad774x_conv_mode_table[AD774X_MAX_CONV_MODE] = {
  76         { "idle", 0 },
  77         { "continuous-conversion", 1 },
  78         { "single-conversion", 2 },
  79         { "power-down", 3 },
  80         { "offset-calibration", 5 },
  81         { "gain-calibration", 6 },
  82 };
  83
  84 /*
  85  * ad774x register access by I2C
  86  */
  87
  88 static int ad774x_i2c_read(struct ad774x_chip_info *chip, u8 reg, u8 *data, int len)
  89 {
  90         struct i2c_client *client = chip->client;
  91         int ret;
  92
  93         ret = i2c_master_send(client, &reg, 1);
  94         if (ret < 0) {
  95                 dev_err(&client->dev, "I2C write error\n");
  96                 return ret;
  97         }
  98
  99         ret = i2c_master_recv(client, data, len);
 100         if (ret < 0) {
 101                 dev_err(&client->dev, "I2C read error\n");
 102                 return ret;
 103         }
 104
 105         return ret;
 106 }
 107
 108 static int ad774x_i2c_write(struct ad774x_chip_info *chip, u8 reg, u8 data)
 109 {
 110         struct i2c_client *client = chip->client;
 111         int ret;
 112
 113         u8 tx[2] = {
 114                 reg,
 115                 data,
 116         };
 117
 118         ret = i2c_master_send(client, tx, 2);
 119         if (ret < 0)
 120                 dev_err(&client->dev, "I2C write error\n");
 121
 122         return ret;
 123 }
 124
 125 /*
 126  * sysfs nodes
 127  */
 128
 129 #define IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(_show)                              \
 130         IIO_DEVICE_ATTR(available_conversion_modes, S_IRUGO, _show, NULL, 0)
 131 #define IIO_DEV_ATTR_CONVERSION_MODE(_mode, _show, _store)              \
 132         IIO_DEVICE_ATTR(conversion_mode, _mode, _show, _store, 0)
 133 #define IIO_DEV_ATTR_CAP_SETUP(_mode, _show, _store)            \
 134         IIO_DEVICE_ATTR(cap_setup, _mode, _show, _store, 0)
 135 #define IIO_DEV_ATTR_VT_SETUP(_mode, _show, _store)              \
 136         IIO_DEVICE_ATTR(in0_setup, _mode, _show, _store, 0)
 137 #define IIO_DEV_ATTR_EXEC_SETUP(_mode, _show, _store)              \
 138         IIO_DEVICE_ATTR(exec_setup, _mode, _show, _store, 0)
 139 #define IIO_DEV_ATTR_VOLT_GAIN(_mode, _show, _store)            \
 140         IIO_DEVICE_ATTR(in0_gain, _mode, _show, _store, 0)
 141 #define IIO_DEV_ATTR_CAP_OFFS(_mode, _show, _store)             \
 142         IIO_DEVICE_ATTR(cap_offs, _mode, _show, _store, 0)
 143 #define IIO_DEV_ATTR_CAP_GAIN(_mode, _show, _store)             \
 144         IIO_DEVICE_ATTR(cap_gain, _mode, _show, _store, 0)
 145 #define IIO_DEV_ATTR_CAP_DATA(_show)            \
 146         IIO_DEVICE_ATTR(cap0_raw, S_IRUGO, _show, NULL, 0)
 147 #define IIO_DEV_ATTR_VT_DATA(_show)             \
 148         IIO_DEVICE_ATTR(in0_raw, S_IRUGO, _show, NULL, 0)
 149
 150 static ssize_t ad774x_show_conversion_modes(struct device *dev,
 151                 struct device_attribute *attr,
 152                 char *buf)
 153 {
 154         int i;
 155         int len = 0;
 156
 157         for (i = 0; i < AD774X_MAX_CONV_MODE; i++)
 158                 len += sprintf(buf + len, "%s ", ad774x_conv_mode_table[i].name);
 159
 160         len += sprintf(buf + len, "\n");
 161
 162         return len;
 163 }
 164
 165 static IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(ad774x_show_conversion_modes);
 166
 167 static ssize_t ad774x_show_conversion_mode(struct device *dev,
 168                 struct device_attribute *attr,
 169                 char *buf)
 170 {
 171         struct iio_dev *dev_info = dev_get_drvdata(dev);
 172         struct ad774x_chip_info *chip = dev_info->dev_data;
 173
 174         return sprintf(buf, "%s\n", chip->conversion_mode);
 175 }
 176
 177 static ssize_t ad774x_store_conversion_mode(struct device *dev,
 178                 struct device_attribute *attr,
 179                 const char *buf,
 180                 size_t len)
 181 {
 182         struct iio_dev *dev_info = dev_get_drvdata(dev);
 183         struct ad774x_chip_info *chip = dev_info->dev_data;
 184         u8 cfg;
 185         int i;
 186
 187         ad774x_i2c_read(chip, AD774X_CFG, &cfg, 1);
 188
 189         for (i = 0; i < AD774X_MAX_CONV_MODE; i++) {
 190                 if (strncmp(buf, ad774x_conv_mode_table[i].name,
 191                                 strlen(ad774x_conv_mode_table[i].name) - 1) == 0) {
 192                         chip->conversion_mode = ad774x_conv_mode_table[i].name;
 193                         cfg |= 0x18 | ad774x_conv_mode_table[i].reg_cfg;
 194                         ad774x_i2c_write(chip, AD774X_CFG, cfg);
 195                         return len;
 196                 }
 197         }
 198
 199         dev_err(dev, "not supported conversion mode\n");
 200
 201         return -EINVAL;
 202 }
 203
 204 static IIO_DEV_ATTR_CONVERSION_MODE(S_IRUGO | S_IWUSR,
 205                 ad774x_show_conversion_mode,
 206                 ad774x_store_conversion_mode);
 207
 208 static ssize_t ad774x_show_dac_value(struct device *dev,
 209                 struct device_attribute *attr,
 210                 char *buf)
 211 {
 212         struct iio_dev *dev_info = dev_get_drvdata(dev);
 213         struct ad774x_chip_info *chip = dev_info->dev_data;
 214         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 215         u8 data;
 216
 217         ad774x_i2c_read(chip, this_attr->address, &data, 1);
 218
 219         return sprintf(buf, "%02x\n", data & 0x7F);
 220 }
 221
 222 static ssize_t ad774x_store_dac_value(struct device *dev,
 223                 struct device_attribute *attr,
 224                 const char *buf,
 225                 size_t len)
 226 {
 227         struct iio_dev *dev_info = dev_get_drvdata(dev);
 228         struct ad774x_chip_info *chip = dev_info->dev_data;
 229         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 230         unsigned long data;
 231         int ret;
 232
 233         ret = strict_strtoul(buf, 10, &data);
 234
 235         if (!ret) {
 236                 ad774x_i2c_write(chip, this_attr->address,
 237                         (data ? AD774X_CAPDAC_EN : 0) | (data & 0x7F));
 238                 return len;
 239         }
 240
 241         return -EINVAL;
 242 }
 243
 244 static IIO_DEVICE_ATTR(capdac0_raw, S_IRUGO | S_IWUSR,
 245                         ad774x_show_dac_value,
 246                         ad774x_store_dac_value,
 247                         AD774X_CAPDACA);
 248
 249 static IIO_DEVICE_ATTR(capdac1_raw, S_IRUGO | S_IWUSR,
 250                         ad774x_show_dac_value,
 251                         ad774x_store_dac_value,
 252                         AD774X_CAPDACB);
 253
 254 static ssize_t ad774x_show_cap_setup(struct device *dev,
 255                 struct device_attribute *attr,
 256                 char *buf)
 257 {
 258         struct iio_dev *dev_info = dev_get_drvdata(dev);
 259         struct ad774x_chip_info *chip = dev_info->dev_data;
 260
 261         return sprintf(buf, "0x%02x\n", chip->cap_setup);
 262 }
 263
 264 static ssize_t ad774x_store_cap_setup(struct device *dev,
 265                 struct device_attribute *attr,
 266                 const char *buf,
 267                 size_t len)
 268 {
 269         struct iio_dev *dev_info = dev_get_drvdata(dev);
 270         struct ad774x_chip_info *chip = dev_info->dev_data;
 271         unsigned long data;
 272         int ret;
 273
 274         ret = strict_strtoul(buf, 10, &data);
 275
 276         if ((!ret) && (data < 0x100)) {
 277                 ad774x_i2c_write(chip, AD774X_CAP_SETUP, data);
 278                 chip->cap_setup = data;
 279                 return len;
 280         }
 281
 282         return -EINVAL;
 283 }
 284
 285 static IIO_DEV_ATTR_CAP_SETUP(S_IRUGO | S_IWUSR,
 286                 ad774x_show_cap_setup,
 287                 ad774x_store_cap_setup);
 288
 289 static ssize_t ad774x_show_vt_setup(struct device *dev,
 290                 struct device_attribute *attr,
 291                 char *buf)
 292 {
 293         struct iio_dev *dev_info = dev_get_drvdata(dev);
 294         struct ad774x_chip_info *chip = dev_info->dev_data;
 295
 296         return sprintf(buf, "0x%02x\n", chip->vt_setup);
 297 }
 298
 299 static ssize_t ad774x_store_vt_setup(struct device *dev,
 300                 struct device_attribute *attr,
 301                 const char *buf,
 302                 size_t len)
 303 {
 304         struct iio_dev *dev_info = dev_get_drvdata(dev);
 305         struct ad774x_chip_info *chip = dev_info->dev_data;
 306         unsigned long data;
 307         int ret;
 308
 309         ret = strict_strtoul(buf, 10, &data);
 310
 311         if ((!ret) && (data < 0x100)) {
 312                 ad774x_i2c_write(chip, AD774X_VT_SETUP, data);
 313                 chip->vt_setup = data;
 314                 return len;
 315         }
 316
 317         return -EINVAL;
 318 }
 319
 320 static IIO_DEV_ATTR_VT_SETUP(S_IRUGO | S_IWUSR,
 321                 ad774x_show_vt_setup,
 322                 ad774x_store_vt_setup);
 323
 324 static ssize_t ad774x_show_exec_setup(struct device *dev,
 325                 struct device_attribute *attr,
 326                 char *buf)
 327 {
 328         struct iio_dev *dev_info = dev_get_drvdata(dev);
 329         struct ad774x_chip_info *chip = dev_info->dev_data;
 330
 331         return sprintf(buf, "0x%02x\n", chip->exec_setup);
 332 }
 333
 334 static ssize_t ad774x_store_exec_setup(struct device *dev,
 335                 struct device_attribute *attr,
 336                 const char *buf,
 337                 size_t len)
 338 {
 339         struct iio_dev *dev_info = dev_get_drvdata(dev);
 340         struct ad774x_chip_info *chip = dev_info->dev_data;
 341         unsigned long data;
 342         int ret;
 343
 344         ret = strict_strtoul(buf, 10, &data);
 345
 346         if ((!ret) && (data < 0x100)) {
 347                 ad774x_i2c_write(chip, AD774X_EXEC_SETUP, data);
 348                 chip->exec_setup = data;
 349                 return len;
 350         }
 351
 352         return -EINVAL;
 353 }
 354
 355 static IIO_DEV_ATTR_EXEC_SETUP(S_IRUGO | S_IWUSR,
 356                 ad774x_show_exec_setup,
 357                 ad774x_store_exec_setup);
 358
 359 static ssize_t ad774x_show_volt_gain(struct device *dev,
 360                 struct device_attribute *attr,
 361                 char *buf)
 362 {
 363         struct iio_dev *dev_info = dev_get_drvdata(dev);
 364         struct ad774x_chip_info *chip = dev_info->dev_data;
 365
 366         return sprintf(buf, "%d\n", chip->volt_gain);
 367 }
 368
 369 static ssize_t ad774x_store_volt_gain(struct device *dev,
 370                 struct device_attribute *attr,
 371                 const char *buf,
 372                 size_t len)
 373 {
 374         struct iio_dev *dev_info = dev_get_drvdata(dev);
 375         struct ad774x_chip_info *chip = dev_info->dev_data;
 376         unsigned long data;
 377         int ret;
 378
 379         ret = strict_strtoul(buf, 10, &data);
 380
 381         if ((!ret) && (data < 0x10000)) {
 382                 ad774x_i2c_write(chip, AD774X_VOLT_GAINH, data >> 8);
 383                 ad774x_i2c_write(chip, AD774X_VOLT_GAINL, data);
 384                 chip->volt_gain = data;
 385                 return len;
 386         }
 387
 388         return -EINVAL;
 389 }
 390
 391 static IIO_DEV_ATTR_VOLT_GAIN(S_IRUGO | S_IWUSR,
 392                 ad774x_show_volt_gain,
 393                 ad774x_store_volt_gain);
 394
 395 static ssize_t ad774x_show_cap_data(struct device *dev,
 396                 struct device_attribute *attr,
 397                 char *buf)
 398 {
 399         struct iio_dev *dev_info = dev_get_drvdata(dev);
 400         struct ad774x_chip_info *chip = dev_info->dev_data;
 401         unsigned long data;
 402         char tmp[3];
 403
 404         ad774x_i2c_read(chip, AD774X_CAP_DATA_HIGH, tmp, 3);
 405         data = ((int)tmp[0] << 16) | ((int)tmp[1] << 8) | (int)tmp[2];
 406
 407         return sprintf(buf, "%ld\n", data);
 408 }
 409
 410 static IIO_DEV_ATTR_CAP_DATA(ad774x_show_cap_data);
 411
 412 static ssize_t ad774x_show_vt_data(struct device *dev,
 413                 struct device_attribute *attr,
 414                 char *buf)
 415 {
 416         struct iio_dev *dev_info = dev_get_drvdata(dev);
 417         struct ad774x_chip_info *chip = dev_info->dev_data;
 418         unsigned long data;
 419         char tmp[3];
 420
 421         ad774x_i2c_read(chip, AD774X_VT_DATA_HIGH, tmp, 3);
 422         data = ((int)tmp[0] << 16) | ((int)tmp[1] << 8) | (int)tmp[2];
 423
 424         return sprintf(buf, "%ld\n", data);
 425 }
 426
 427 static IIO_DEV_ATTR_VT_DATA(ad774x_show_vt_data);
 428
 429 static ssize_t ad774x_show_cap_offs(struct device *dev,
 430                 struct device_attribute *attr,
 431                 char *buf)
 432 {
 433         struct iio_dev *dev_info = dev_get_drvdata(dev);
 434         struct ad774x_chip_info *chip = dev_info->dev_data;
 435
 436         return sprintf(buf, "%d\n", chip->cap_offs);
 437 }
 438
 439 static ssize_t ad774x_store_cap_offs(struct device *dev,
 440                 struct device_attribute *attr,
 441                 const char *buf,
 442                 size_t len)
 443 {
 444         struct iio_dev *dev_info = dev_get_drvdata(dev);
 445         struct ad774x_chip_info *chip = dev_info->dev_data;
 446         unsigned long data;
 447         int ret;
 448
 449         ret = strict_strtoul(buf, 10, &data);
 450
 451         if ((!ret) && (data < 0x10000)) {
 452                 ad774x_i2c_write(chip, AD774X_CAP_OFFH, data >> 8);
 453                 ad774x_i2c_write(chip, AD774X_CAP_OFFL, data);
 454                 chip->cap_offs = data;
 455                 return len;
 456         }
 457
 458         return -EINVAL;
 459 }
 460
 461 static IIO_DEV_ATTR_CAP_OFFS(S_IRUGO | S_IWUSR,
 462                 ad774x_show_cap_offs,
 463                 ad774x_store_cap_offs);
 464
 465 static ssize_t ad774x_show_cap_gain(struct device *dev,
 466                 struct device_attribute *attr,
 467                 char *buf)
 468 {
 469         struct iio_dev *dev_info = dev_get_drvdata(dev);
 470         struct ad774x_chip_info *chip = dev_info->dev_data;
 471
 472         return sprintf(buf, "%d\n", chip->cap_gain);
 473 }
 474
 475 static ssize_t ad774x_store_cap_gain(struct device *dev,
 476                 struct device_attribute *attr,
 477                 const char *buf,
 478                 size_t len)
 479 {
 480         struct iio_dev *dev_info = dev_get_drvdata(dev);
 481         struct ad774x_chip_info *chip = dev_info->dev_data;
 482         unsigned long data;
 483         int ret;
 484
 485         ret = strict_strtoul(buf, 10, &data);
 486
 487         if ((!ret) && (data < 0x10000)) {
 488                 ad774x_i2c_write(chip, AD774X_CAP_GAINH, data >> 8);
 489                 ad774x_i2c_write(chip, AD774X_CAP_GAINL, data);
 490                 chip->cap_gain = data;
 491                 return len;
 492         }
 493
 494         return -EINVAL;
 495 }
 496
 497 static IIO_DEV_ATTR_CAP_GAIN(S_IRUGO | S_IWUSR,
 498                 ad774x_show_cap_gain,
 499                 ad774x_store_cap_gain);
 500
 501 static struct attribute *ad774x_attributes[] = {
 502         &iio_dev_attr_available_conversion_modes.dev_attr.attr,
 503         &iio_dev_attr_conversion_mode.dev_attr.attr,
 504         &iio_dev_attr_cap_setup.dev_attr.attr,
 505         &iio_dev_attr_in0_setup.dev_attr.attr,
 506         &iio_dev_attr_exec_setup.dev_attr.attr,
 507         &iio_dev_attr_cap_offs.dev_attr.attr,
 508         &iio_dev_attr_cap_gain.dev_attr.attr,
 509         &iio_dev_attr_in0_gain.dev_attr.attr,
 510         &iio_dev_attr_in0_raw.dev_attr.attr,
 511         &iio_dev_attr_cap0_raw.dev_attr.attr,
 512         &iio_dev_attr_capdac0_raw.dev_attr.attr,
 513         &iio_dev_attr_capdac1_raw.dev_attr.attr,
 514         NULL,
 515 };
 516
 517 static const struct attribute_group ad774x_attribute_group = {
 518         .attrs = ad774x_attributes,
 519 };
 520
 521 /*
 522  * data ready events
 523  */
 524
 525 #define IIO_EVENT_CODE_CAP_RDY     0
 526 #define IIO_EVENT_CODE_VT_RDY      1
 527
 528 #define IIO_EVENT_ATTR_CAP_RDY_SH(_evlist, _show, _store, _mask)        \
 529         IIO_EVENT_ATTR_SH(cap_rdy, _evlist, _show, _store, _mask)
 530
 531 #define IIO_EVENT_ATTR_VT_RDY_SH(_evlist, _show, _store, _mask) \
 532         IIO_EVENT_ATTR_SH(vt_rdy, _evlist, _show, _store, _mask)
 533
 534 static irqreturn_t ad774x_event_handler(int irq, void *private)
 535 {
 536         struct iio_dev *indio_dev = private;
 537         struct ad774x_chip_info *chip = iio_dev_get_devdata(indio_dev);
 538         u8 int_status;
 539
 540         ad774x_i2c_read(chip, AD774X_STATUS, &int_status, 1);
 541
 542         if (int_status & AD774X_STATUS_RDYCAP)
 543                 iio_push_event(indio_dev, 0,
 544                                IIO_EVENT_CODE_CAP_RDY,
 545                                iio_get_time_ns());
 546
 547         if (int_status & AD774X_STATUS_RDYVT)
 548                 iio_push_event(indio_dev, 0,
 549                                IIO_EVENT_CODE_VT_RDY,
 550                                iio_get_time_ns());
 551
 552         return IRQ_HANDLED;
 553 }
 554
 555 static IIO_CONST_ATTR(cap_rdy_en, "1");
 556 static IIO_CONST_ATTR(vt_rdy_en, "1");
 557
 558 static struct attribute *ad774x_event_attributes[] = {
 559         &iio_const_attr_cap_rdy_en.dev_attr.attr,
 560         &iio_const_attr_vt_rdy_en.dev_attr.attr,
 561         NULL,
 562 };
 563
 564 static struct attribute_group ad774x_event_attribute_group = {
 565         .attrs = ad774x_event_attributes,
 566 };
 567
 568 /*
 569  * device probe and remove
 570  */
 571
 572 static int __devinit ad774x_probe(struct i2c_client *client,
 573                 const struct i2c_device_id *id)
 574 {
 575         int ret = 0, regdone = 0;
 576         struct ad774x_chip_info *chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 577         if (chip == NULL) {
 578                 ret = -ENOMEM;
 579                 goto error_ret;
 580         }
 581
 582         /* this is only used for device removal purposes */
 583         i2c_set_clientdata(client, chip);
 584
 585         chip->client = client;
 586
 587         chip->indio_dev = iio_allocate_device(0);
 588         if (chip->indio_dev == NULL) {
 589                 ret = -ENOMEM;
 590                 goto error_free_chip;
 591         }
 592
 593         /* Establish that the iio_dev is a child of the i2c device */
 594         chip->indio_dev->name = id->name;
 595         chip->indio_dev->dev.parent = &client->dev;
 596         chip->indio_dev->attrs = &ad774x_attribute_group;
 597         chip->indio_dev->event_attrs = &ad774x_event_attribute_group;
 598         chip->indio_dev->dev_data = (void *)(chip);
 599         chip->indio_dev->driver_module = THIS_MODULE;
 600         chip->indio_dev->num_interrupt_lines = 1;
 601         chip->indio_dev->modes = INDIO_DIRECT_MODE;
 602
 603         ret = iio_device_register(chip->indio_dev);
 604         if (ret)
 605                 goto error_free_dev;
 606         regdone = 1;
 607
 608         if (client->irq) {
 609                 ret = request_threaded_irq(client->irq,
 610                                            NULL,
 611                                            &ad774x_event_handler,
 612                                            IRQF_TRIGGER_FALLING,
 613                                            "ad774x",
 614                                            chip->indio_dev);
 615                 if (ret)
 616                         goto error_free_dev;
 617         }
 618
 619         dev_err(&client->dev, "%s capacitive sensor registered, irq: %d\n", id->name, client->irq);
 620
 621         return 0;
 622
 623 error_free_dev:
 624         if (regdone)
 625                 free_irq(client->irq, chip->indio_dev);
 626         else
 627                 iio_free_device(chip->indio_dev);
 628 error_free_chip:
 629         kfree(chip);
 630 error_ret:
 631         return ret;
 632 }
 633
 634 static int __devexit ad774x_remove(struct i2c_client *client)
 635 {
 636         struct ad774x_chip_info *chip = i2c_get_clientdata(client);
 637         struct iio_dev *indio_dev = chip->indio_dev;
 638
 639         if (client->irq)
 640                 free_irq(client->irq, indio_dev);
 641         iio_device_unregister(indio_dev);
 642         kfree(chip);
 643
 644         return 0;
 645 }
 646
 647 static const struct i2c_device_id ad774x_id[] = {
 648         { "ad7745", 0 },
 649         { "ad7746", 0 },
 650         { "ad7747", 0 },
 651         {}
 652 };
 653
 654 MODULE_DEVICE_TABLE(i2c, ad774x_id);
 655
 656 static struct i2c_driver ad774x_driver = {
 657         .driver = {
 658                 .name = "ad774x",
 659         },
 660         .probe = ad774x_probe,
 661         .remove = __devexit_p(ad774x_remove),
 662         .id_table = ad774x_id,
 663 };
 664
 665 static __init int ad774x_init(void)
 666 {
 667         return i2c_add_driver(&ad774x_driver);
 668 }
 669
 670 static __exit void ad774x_exit(void)
 671 {
 672         i2c_del_driver(&ad774x_driver);
 673 }
 674
 675 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 676 MODULE_DESCRIPTION("Analog Devices ad7745/6/7 capacitive sensor driver");
 677 MODULE_LICENSE("GPL v2");
 678
 679 module_init(ad774x_init);
 680 module_exit(ad774x_exit);