drivers/iio/adc/ad7606.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AD7606 SPI ADC driver
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/device.h>
  10 #include <linux/err.h>
  11 #include <linux/gpio/consumer.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/sysfs.h>
  19 #include <linux/util_macros.h>
  20
  21 #include <linux/iio/iio.h>
  22 #include <linux/iio/buffer.h>
  23 #include <linux/iio/sysfs.h>
  24 #include <linux/iio/trigger.h>
  25 #include <linux/iio/triggered_buffer.h>
  26 #include <linux/iio/trigger_consumer.h>
  27
  28 #include "ad7606.h"
  29
  30 /*
  31  * Scales are computed as 5000/32768 and 10000/32768 respectively,
  32  * so that when applied to the raw values they provide mV values
  33  */
  34 static const unsigned int ad7606_scale_avail[2] = {
  35         152588, 305176
  36 };
  37
  38 static const unsigned int ad7606_oversampling_avail[7] = {
  39         1, 2, 4, 8, 16, 32, 64,
  40 };
  41
  42 static const unsigned int ad7616_oversampling_avail[8] = {
  43         1, 2, 4, 8, 16, 32, 64, 128,
  44 };
  45
  46 static int ad7606_reset(struct ad7606_state *st)
  47 {
  48         if (st->gpio_reset) {
  49                 gpiod_set_value(st->gpio_reset, 1);
  50                 ndelay(100); /* t_reset >= 100ns */
  51                 gpiod_set_value(st->gpio_reset, 0);
  52                 return 0;
  53         }
  54
  55         return -ENODEV;
  56 }
  57
  58 static int ad7606_read_samples(struct ad7606_state *st)
  59 {
  60         unsigned int num = st->chip_info->num_channels;
  61         u16 *data = st->data;
  62         int ret;
  63
  64         /*
  65          * The frstdata signal is set to high while and after reading the sample
  66          * of the first channel and low for all other channels. This can be used
  67          * to check that the incoming data is correctly aligned. During normal
  68          * operation the data should never become unaligned, but some glitch or
  69          * electrostatic discharge might cause an extra read or clock cycle.
  70          * Monitoring the frstdata signal allows to recover from such failure
  71          * situations.
  72          */
  73
  74         if (st->gpio_frstdata) {
  75                 ret = st->bops->read_block(st->dev, 1, data);
  76                 if (ret)
  77                         return ret;
  78
  79                 if (!gpiod_get_value(st->gpio_frstdata)) {
  80                         ad7606_reset(st);
  81                         return -EIO;
  82                 }
  83
  84                 data++;
  85                 num--;
  86         }
  87
  88         return st->bops->read_block(st->dev, num, data);
  89 }
  90
  91 static irqreturn_t ad7606_trigger_handler(int irq, void *p)
  92 {
  93         struct iio_poll_func *pf = p;
  94         struct iio_dev *indio_dev = pf->indio_dev;
  95         struct ad7606_state *st = iio_priv(indio_dev);
  96         int ret;
  97
  98         mutex_lock(&st->lock);
  99
 100         ret = ad7606_read_samples(st);
 101         if (ret == 0)
 102                 iio_push_to_buffers_with_timestamp(indio_dev, st->data,
 103                                                    iio_get_time_ns(indio_dev));
 104
 105         iio_trigger_notify_done(indio_dev->trig);
 106         /* The rising edge of the CONVST signal starts a new conversion. */
 107         gpiod_set_value(st->gpio_convst, 1);
 108
 109         mutex_unlock(&st->lock);
 110
 111         return IRQ_HANDLED;
 112 }
 113
 114 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
 115 {
 116         struct ad7606_state *st = iio_priv(indio_dev);
 117         int ret;
 118
 119         gpiod_set_value(st->gpio_convst, 1);
 120         ret = wait_for_completion_timeout(&st->completion,
 121                                           msecs_to_jiffies(1000));
 122         if (!ret) {
 123                 ret = -ETIMEDOUT;
 124                 goto error_ret;
 125         }
 126
 127         ret = ad7606_read_samples(st);
 128         if (ret == 0)
 129                 ret = st->data[ch];
 130
 131 error_ret:
 132         gpiod_set_value(st->gpio_convst, 0);
 133
 134         return ret;
 135 }
 136
 137 static int ad7606_read_raw(struct iio_dev *indio_dev,
 138                            struct iio_chan_spec const *chan,
 139                            int *val,
 140                            int *val2,
 141                            long m)
 142 {
 143         int ret;
 144         struct ad7606_state *st = iio_priv(indio_dev);
 145
 146         switch (m) {
 147         case IIO_CHAN_INFO_RAW:
 148                 ret = iio_device_claim_direct_mode(indio_dev);
 149                 if (ret)
 150                         return ret;
 151
 152                 ret = ad7606_scan_direct(indio_dev, chan->address);
 153                 iio_device_release_direct_mode(indio_dev);
 154
 155                 if (ret < 0)
 156                         return ret;
 157                 *val = (short)ret;
 158                 return IIO_VAL_INT;
 159         case IIO_CHAN_INFO_SCALE:
 160                 *val = 0;
 161                 *val2 = st->scale_avail[st->range];
 162                 return IIO_VAL_INT_PLUS_MICRO;
 163         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 164                 *val = st->oversampling;
 165                 return IIO_VAL_INT;
 166         }
 167         return -EINVAL;
 168 }
 169
 170 static ssize_t ad7606_show_avail(char *buf, const unsigned int *vals,
 171                                  unsigned int n, bool micros)
 172 {
 173         size_t len = 0;
 174         int i;
 175
 176         for (i = 0; i < n; i++) {
 177                 len += scnprintf(buf + len, PAGE_SIZE - len,
 178                         micros ? "0.%06u " : "%u ", vals[i]);
 179         }
 180         buf[len - 1] = '\n';
 181
 182         return len;
 183 }
 184
 185 static ssize_t in_voltage_scale_available_show(struct device *dev,
 186                                                struct device_attribute *attr,
 187                                                char *buf)
 188 {
 189         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 190         struct ad7606_state *st = iio_priv(indio_dev);
 191
 192         return ad7606_show_avail(buf, st->scale_avail, st->num_scales, true);
 193 }
 194
 195 static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
 196
 197 static int ad7606_write_raw(struct iio_dev *indio_dev,
 198                             struct iio_chan_spec const *chan,
 199                             int val,
 200                             int val2,
 201                             long mask)
 202 {
 203         struct ad7606_state *st = iio_priv(indio_dev);
 204         DECLARE_BITMAP(values, 3);
 205         int i;
 206
 207         switch (mask) {
 208         case IIO_CHAN_INFO_SCALE:
 209                 mutex_lock(&st->lock);
 210                 i = find_closest(val2, st->scale_avail, st->num_scales);
 211                 gpiod_set_value(st->gpio_range, i);
 212                 st->range = i;
 213                 mutex_unlock(&st->lock);
 214
 215                 return 0;
 216         case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 217                 if (val2)
 218                         return -EINVAL;
 219                 i = find_closest(val, st->oversampling_avail,
 220                                  st->num_os_ratios);
 221
 222                 values[0] = i;
 223
 224                 mutex_lock(&st->lock);
 225                 gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
 226                                       st->gpio_os->info, values);
 227
 228                 /* AD7616 requires a reset to update value */
 229                 if (st->chip_info->os_req_reset)
 230                         ad7606_reset(st);
 231
 232                 st->oversampling = st->oversampling_avail[i];
 233                 mutex_unlock(&st->lock);
 234
 235                 return 0;
 236         default:
 237                 return -EINVAL;
 238         }
 239 }
 240
 241 static ssize_t ad7606_oversampling_ratio_avail(struct device *dev,
 242                                                struct device_attribute *attr,
 243                                                char *buf)
 244 {
 245         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 246         struct ad7606_state *st = iio_priv(indio_dev);
 247
 248         return ad7606_show_avail(buf, st->oversampling_avail,
 249                                  st->num_os_ratios, false);
 250 }
 251
 252 static IIO_DEVICE_ATTR(oversampling_ratio_available, 0444,
 253                        ad7606_oversampling_ratio_avail, NULL, 0);
 254
 255 static struct attribute *ad7606_attributes_os_and_range[] = {
 256         &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
 257         &iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
 258         NULL,
 259 };
 260
 261 static const struct attribute_group ad7606_attribute_group_os_and_range = {
 262         .attrs = ad7606_attributes_os_and_range,
 263 };
 264
 265 static struct attribute *ad7606_attributes_os[] = {
 266         &iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
 267         NULL,
 268 };
 269
 270 static const struct attribute_group ad7606_attribute_group_os = {
 271         .attrs = ad7606_attributes_os,
 272 };
 273
 274 static struct attribute *ad7606_attributes_range[] = {
 275         &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
 276         NULL,
 277 };
 278
 279 static const struct attribute_group ad7606_attribute_group_range = {
 280         .attrs = ad7606_attributes_range,
 281 };
 282
 283 #define AD760X_CHANNEL(num, mask) {                             \
 284                 .type = IIO_VOLTAGE,                            \
 285                 .indexed = 1,                                   \
 286                 .channel = num,                                 \
 287                 .address = num,                                 \
 288                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
 289                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
 290                 .info_mask_shared_by_all = mask,                \
 291                 .scan_index = num,                              \
 292                 .scan_type = {                                  \
 293                         .sign = 's',                            \
 294                         .realbits = 16,                         \
 295                         .storagebits = 16,                      \
 296                         .endianness = IIO_CPU,                  \
 297                 },                                              \
 298 }
 299
 300 #define AD7605_CHANNEL(num)     \
 301         AD760X_CHANNEL(num, 0)
 302
 303 #define AD7606_CHANNEL(num)     \
 304         AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
 305
 306 static const struct iio_chan_spec ad7605_channels[] = {
 307         IIO_CHAN_SOFT_TIMESTAMP(4),
 308         AD7605_CHANNEL(0),
 309         AD7605_CHANNEL(1),
 310         AD7605_CHANNEL(2),
 311         AD7605_CHANNEL(3),
 312 };
 313
 314 static const struct iio_chan_spec ad7606_channels[] = {
 315         IIO_CHAN_SOFT_TIMESTAMP(8),
 316         AD7606_CHANNEL(0),
 317         AD7606_CHANNEL(1),
 318         AD7606_CHANNEL(2),
 319         AD7606_CHANNEL(3),
 320         AD7606_CHANNEL(4),
 321         AD7606_CHANNEL(5),
 322         AD7606_CHANNEL(6),
 323         AD7606_CHANNEL(7),
 324 };
 325
 326 /*
 327  * The current assumption that this driver makes for AD7616, is that it's
 328  * working in Hardware Mode with Serial, Burst and Sequencer modes activated.
 329  * To activate them, following pins must be pulled high:
 330  *      -SER/PAR
 331  *      -SEQEN
 332  * And following pins must be pulled low:
 333  *      -WR/BURST
 334  *      -DB4/SER1W
 335  */
 336 static const struct iio_chan_spec ad7616_channels[] = {
 337         IIO_CHAN_SOFT_TIMESTAMP(16),
 338         AD7606_CHANNEL(0),
 339         AD7606_CHANNEL(1),
 340         AD7606_CHANNEL(2),
 341         AD7606_CHANNEL(3),
 342         AD7606_CHANNEL(4),
 343         AD7606_CHANNEL(5),
 344         AD7606_CHANNEL(6),
 345         AD7606_CHANNEL(7),
 346         AD7606_CHANNEL(8),
 347         AD7606_CHANNEL(9),
 348         AD7606_CHANNEL(10),
 349         AD7606_CHANNEL(11),
 350         AD7606_CHANNEL(12),
 351         AD7606_CHANNEL(13),
 352         AD7606_CHANNEL(14),
 353         AD7606_CHANNEL(15),
 354 };
 355
 356 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
 357         /* More devices added in future */
 358         [ID_AD7605_4] = {
 359                 .channels = ad7605_channels,
 360                 .num_channels = 5,
 361         },
 362         [ID_AD7606_8] = {
 363                 .channels = ad7606_channels,
 364                 .num_channels = 9,
 365                 .oversampling_avail = ad7606_oversampling_avail,
 366                 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 367         },
 368         [ID_AD7606_6] = {
 369                 .channels = ad7606_channels,
 370                 .num_channels = 7,
 371                 .oversampling_avail = ad7606_oversampling_avail,
 372                 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 373         },
 374         [ID_AD7606_4] = {
 375                 .channels = ad7606_channels,
 376                 .num_channels = 5,
 377                 .oversampling_avail = ad7606_oversampling_avail,
 378                 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
 379         },
 380         [ID_AD7616] = {
 381                 .channels = ad7616_channels,
 382                 .num_channels = 17,
 383                 .oversampling_avail = ad7616_oversampling_avail,
 384                 .oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
 385                 .os_req_reset = true,
 386         },
 387 };
 388
 389 static int ad7606_request_gpios(struct ad7606_state *st)
 390 {
 391         struct device *dev = st->dev;
 392
 393         st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
 394                                          GPIOD_OUT_LOW);
 395         if (IS_ERR(st->gpio_convst))
 396                 return PTR_ERR(st->gpio_convst);
 397
 398         st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
 399         if (IS_ERR(st->gpio_reset))
 400                 return PTR_ERR(st->gpio_reset);
 401
 402         st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
 403                                                  GPIOD_OUT_LOW);
 404         if (IS_ERR(st->gpio_range))
 405                 return PTR_ERR(st->gpio_range);
 406
 407         st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
 408                                                    GPIOD_OUT_HIGH);
 409         if (IS_ERR(st->gpio_standby))
 410                 return PTR_ERR(st->gpio_standby);
 411
 412         st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
 413                                                     GPIOD_IN);
 414         if (IS_ERR(st->gpio_frstdata))
 415                 return PTR_ERR(st->gpio_frstdata);
 416
 417         if (!st->chip_info->oversampling_num)
 418                 return 0;
 419
 420         st->gpio_os = devm_gpiod_get_array_optional(dev,
 421                                                     "adi,oversampling-ratio",
 422                                                     GPIOD_OUT_LOW);
 423         return PTR_ERR_OR_ZERO(st->gpio_os);
 424 }
 425
 426 /*
 427  * The BUSY signal indicates when conversions are in progress, so when a rising
 428  * edge of CONVST is applied, BUSY goes logic high and transitions low at the
 429  * end of the entire conversion process. The falling edge of the BUSY signal
 430  * triggers this interrupt.
 431  */
 432 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
 433 {
 434         struct iio_dev *indio_dev = dev_id;
 435         struct ad7606_state *st = iio_priv(indio_dev);
 436
 437         if (iio_buffer_enabled(indio_dev)) {
 438                 gpiod_set_value(st->gpio_convst, 0);
 439                 iio_trigger_poll_chained(st->trig);
 440         } else {
 441                 complete(&st->completion);
 442         }
 443
 444         return IRQ_HANDLED;
 445 };
 446
 447 static int ad7606_validate_trigger(struct iio_dev *indio_dev,
 448                                    struct iio_trigger *trig)
 449 {
 450         struct ad7606_state *st = iio_priv(indio_dev);
 451
 452         if (st->trig != trig)
 453                 return -EINVAL;
 454
 455         return 0;
 456 }
 457
 458 static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
 459 {
 460         struct ad7606_state *st = iio_priv(indio_dev);
 461
 462         iio_triggered_buffer_postenable(indio_dev);
 463         gpiod_set_value(st->gpio_convst, 1);
 464
 465         return 0;
 466 }
 467
 468 static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
 469 {
 470         struct ad7606_state *st = iio_priv(indio_dev);
 471
 472         gpiod_set_value(st->gpio_convst, 0);
 473
 474         return iio_triggered_buffer_predisable(indio_dev);
 475 }
 476
 477 static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
 478         .postenable = &ad7606_buffer_postenable,
 479         .predisable = &ad7606_buffer_predisable,
 480 };
 481
 482 static const struct iio_info ad7606_info_no_os_or_range = {
 483         .read_raw = &ad7606_read_raw,
 484         .validate_trigger = &ad7606_validate_trigger,
 485 };
 486
 487 static const struct iio_info ad7606_info_os_and_range = {
 488         .read_raw = &ad7606_read_raw,
 489         .write_raw = &ad7606_write_raw,
 490         .attrs = &ad7606_attribute_group_os_and_range,
 491         .validate_trigger = &ad7606_validate_trigger,
 492 };
 493
 494 static const struct iio_info ad7606_info_os = {
 495         .read_raw = &ad7606_read_raw,
 496         .write_raw = &ad7606_write_raw,
 497         .attrs = &ad7606_attribute_group_os,
 498         .validate_trigger = &ad7606_validate_trigger,
 499 };
 500
 501 static const struct iio_info ad7606_info_range = {
 502         .read_raw = &ad7606_read_raw,
 503         .write_raw = &ad7606_write_raw,
 504         .attrs = &ad7606_attribute_group_range,
 505         .validate_trigger = &ad7606_validate_trigger,
 506 };
 507
 508 static const struct iio_trigger_ops ad7606_trigger_ops = {
 509         .validate_device = iio_trigger_validate_own_device,
 510 };
 511
 512 static void ad7606_regulator_disable(void *data)
 513 {
 514         struct ad7606_state *st = data;
 515
 516         regulator_disable(st->reg);
 517 }
 518
 519 int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
 520                  const char *name, unsigned int id,
 521                  const struct ad7606_bus_ops *bops)
 522 {
 523         struct ad7606_state *st;
 524         int ret;
 525         struct iio_dev *indio_dev;
 526
 527         indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 528         if (!indio_dev)
 529                 return -ENOMEM;
 530
 531         st = iio_priv(indio_dev);
 532         dev_set_drvdata(dev, indio_dev);
 533
 534         st->dev = dev;
 535         mutex_init(&st->lock);
 536         st->bops = bops;
 537         st->base_address = base_address;
 538         /* tied to logic low, analog input range is +/- 5V */
 539         st->range = 0;
 540         st->oversampling = 1;
 541         st->scale_avail = ad7606_scale_avail;
 542         st->num_scales = ARRAY_SIZE(ad7606_scale_avail);
 543
 544         st->reg = devm_regulator_get(dev, "avcc");
 545         if (IS_ERR(st->reg))
 546                 return PTR_ERR(st->reg);
 547
 548         ret = regulator_enable(st->reg);
 549         if (ret) {
 550                 dev_err(dev, "Failed to enable specified AVcc supply\n");
 551                 return ret;
 552         }
 553
 554         ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
 555         if (ret)
 556                 return ret;
 557
 558         st->chip_info = &ad7606_chip_info_tbl[id];
 559
 560         if (st->chip_info->oversampling_num) {
 561                 st->oversampling_avail = st->chip_info->oversampling_avail;
 562                 st->num_os_ratios = st->chip_info->oversampling_num;
 563         }
 564
 565         ret = ad7606_request_gpios(st);
 566         if (ret)
 567                 return ret;
 568
 569         indio_dev->dev.parent = dev;
 570         if (st->gpio_os) {
 571                 if (st->gpio_range)
 572                         indio_dev->info = &ad7606_info_os_and_range;
 573                 else
 574                         indio_dev->info = &ad7606_info_os;
 575         } else {
 576                 if (st->gpio_range)
 577                         indio_dev->info = &ad7606_info_range;
 578                 else
 579                         indio_dev->info = &ad7606_info_no_os_or_range;
 580         }
 581         indio_dev->modes = INDIO_DIRECT_MODE;
 582         indio_dev->name = name;
 583         indio_dev->channels = st->chip_info->channels;
 584         indio_dev->num_channels = st->chip_info->num_channels;
 585
 586         init_completion(&st->completion);
 587
 588         ret = ad7606_reset(st);
 589         if (ret)
 590                 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
 591
 592         st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
 593                                           indio_dev->name, indio_dev->id);
 594         if (!st->trig)
 595                 return -ENOMEM;
 596
 597         st->trig->ops = &ad7606_trigger_ops;
 598         st->trig->dev.parent = dev;
 599         iio_trigger_set_drvdata(st->trig, indio_dev);
 600         ret = devm_iio_trigger_register(dev, st->trig);
 601         if (ret)
 602                 return ret;
 603
 604         indio_dev->trig = iio_trigger_get(st->trig);
 605
 606         ret = devm_request_threaded_irq(dev, irq,
 607                                         NULL,
 608                                         &ad7606_interrupt,
 609                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 610                                         name, indio_dev);
 611         if (ret)
 612                 return ret;
 613
 614         ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
 615                                               &iio_pollfunc_store_time,
 616                                               &ad7606_trigger_handler,
 617                                               &ad7606_buffer_ops);
 618         if (ret)
 619                 return ret;
 620
 621         return devm_iio_device_register(dev, indio_dev);
 622 }
 623 EXPORT_SYMBOL_GPL(ad7606_probe);
 624
 625 #ifdef CONFIG_PM_SLEEP
 626
 627 static int ad7606_suspend(struct device *dev)
 628 {
 629         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 630         struct ad7606_state *st = iio_priv(indio_dev);
 631
 632         if (st->gpio_standby) {
 633                 gpiod_set_value(st->gpio_range, 1);
 634                 gpiod_set_value(st->gpio_standby, 0);
 635         }
 636
 637         return 0;
 638 }
 639
 640 static int ad7606_resume(struct device *dev)
 641 {
 642         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 643         struct ad7606_state *st = iio_priv(indio_dev);
 644
 645         if (st->gpio_standby) {
 646                 gpiod_set_value(st->gpio_range, st->range);
 647                 gpiod_set_value(st->gpio_standby, 1);
 648                 ad7606_reset(st);
 649         }
 650
 651         return 0;
 652 }
 653
 654 SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
 655 EXPORT_SYMBOL_GPL(ad7606_pm_ops);
 656
 657 #endif
 658
 659 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 660 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 661 MODULE_LICENSE("GPL v2");