drivers/staging/iio/adc/ad7606_core.c

   1 /*
   2  * AD7606 SPI ADC driver
   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/regulator/consumer.h>
  15 #include <linux/err.h>
  16 #include <linux/gpio.h>
  17 #include <linux/delay.h>
  18 #include <linux/sched.h>
  19 #include <linux/module.h>
  20
  21 #include <linux/iio/iio.h>
  22 #include <linux/iio/sysfs.h>
  23 #include <linux/iio/buffer.h>
  24
  25 #include "ad7606.h"
  26
  27 int ad7606_reset(struct ad7606_state *st)
  28 {
  29         if (gpio_is_valid(st->pdata->gpio_reset)) {
  30                 gpio_set_value(st->pdata->gpio_reset, 1);
  31                 ndelay(100); /* t_reset >= 100ns */
  32                 gpio_set_value(st->pdata->gpio_reset, 0);
  33                 return 0;
  34         }
  35
  36         return -ENODEV;
  37 }
  38
  39 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned ch)
  40 {
  41         struct ad7606_state *st = iio_priv(indio_dev);
  42         int ret;
  43
  44         st->done = false;
  45         gpio_set_value(st->pdata->gpio_convst, 1);
  46
  47         ret = wait_event_interruptible(st->wq_data_avail, st->done);
  48         if (ret)
  49                 goto error_ret;
  50
  51         if (gpio_is_valid(st->pdata->gpio_frstdata)) {
  52                 ret = st->bops->read_block(st->dev, 1, st->data);
  53                 if (ret)
  54                         goto error_ret;
  55                 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
  56                         /* This should never happen */
  57                         ad7606_reset(st);
  58                         ret = -EIO;
  59                         goto error_ret;
  60                 }
  61                 ret = st->bops->read_block(st->dev,
  62                         st->chip_info->num_channels - 1, &st->data[1]);
  63                 if (ret)
  64                         goto error_ret;
  65         } else {
  66                 ret = st->bops->read_block(st->dev,
  67                         st->chip_info->num_channels, st->data);
  68                 if (ret)
  69                         goto error_ret;
  70         }
  71
  72         ret = st->data[ch];
  73
  74 error_ret:
  75         gpio_set_value(st->pdata->gpio_convst, 0);
  76
  77         return ret;
  78 }
  79
  80 static int ad7606_read_raw(struct iio_dev *indio_dev,
  81                            struct iio_chan_spec const *chan,
  82                            int *val,
  83                            int *val2,
  84                            long m)
  85 {
  86         int ret;
  87         struct ad7606_state *st = iio_priv(indio_dev);
  88         unsigned int scale_uv;
  89
  90         switch (m) {
  91         case IIO_CHAN_INFO_RAW:
  92                 mutex_lock(&indio_dev->mlock);
  93                 if (iio_buffer_enabled(indio_dev))
  94                         ret = -EBUSY;
  95                 else
  96                         ret = ad7606_scan_direct(indio_dev, chan->address);
  97                 mutex_unlock(&indio_dev->mlock);
  98
  99                 if (ret < 0)
 100                         return ret;
 101                 *val = (short) ret;
 102                 return IIO_VAL_INT;
 103         case IIO_CHAN_INFO_SCALE:
 104                 scale_uv = (st->range * 1000 * 2)
 105                         >> st->chip_info->channels[0].scan_type.realbits;
 106                 *val =  scale_uv / 1000;
 107                 *val2 = (scale_uv % 1000) * 1000;
 108                 return IIO_VAL_INT_PLUS_MICRO;
 109         }
 110         return -EINVAL;
 111 }
 112
 113 static ssize_t ad7606_show_range(struct device *dev,
 114                         struct device_attribute *attr, char *buf)
 115 {
 116         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 117         struct ad7606_state *st = iio_priv(indio_dev);
 118
 119         return sprintf(buf, "%u\n", st->range);
 120 }
 121
 122 static ssize_t ad7606_store_range(struct device *dev,
 123                 struct device_attribute *attr, const char *buf, size_t count)
 124 {
 125         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 126         struct ad7606_state *st = iio_priv(indio_dev);
 127         unsigned long lval;
 128
 129         if (strict_strtoul(buf, 10, &lval))
 130                 return -EINVAL;
 131         if (!(lval == 5000 || lval == 10000)) {
 132                 dev_err(dev, "range is not supported\n");
 133                 return -EINVAL;
 134         }
 135         mutex_lock(&indio_dev->mlock);
 136         gpio_set_value(st->pdata->gpio_range, lval == 10000);
 137         st->range = lval;
 138         mutex_unlock(&indio_dev->mlock);
 139
 140         return count;
 141 }
 142
 143 static IIO_DEVICE_ATTR(in_voltage_range, S_IRUGO | S_IWUSR, \
 144                        ad7606_show_range, ad7606_store_range, 0);
 145 static IIO_CONST_ATTR(in_voltage_range_available, "5000 10000");
 146
 147 static ssize_t ad7606_show_oversampling_ratio(struct device *dev,
 148                         struct device_attribute *attr, char *buf)
 149 {
 150         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 151         struct ad7606_state *st = iio_priv(indio_dev);
 152
 153         return sprintf(buf, "%u\n", st->oversampling);
 154 }
 155
 156 static int ad7606_oversampling_get_index(unsigned val)
 157 {
 158         unsigned char supported[] = {0, 2, 4, 8, 16, 32, 64};
 159         int i;
 160
 161         for (i = 0; i < ARRAY_SIZE(supported); i++)
 162                 if (val == supported[i])
 163                         return i;
 164
 165         return -EINVAL;
 166 }
 167
 168 static ssize_t ad7606_store_oversampling_ratio(struct device *dev,
 169                 struct device_attribute *attr, const char *buf, size_t count)
 170 {
 171         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 172         struct ad7606_state *st = iio_priv(indio_dev);
 173         unsigned long lval;
 174         int ret;
 175
 176         if (strict_strtoul(buf, 10, &lval))
 177                 return -EINVAL;
 178
 179         ret = ad7606_oversampling_get_index(lval);
 180         if (ret < 0) {
 181                 dev_err(dev, "oversampling %lu is not supported\n", lval);
 182                 return ret;
 183         }
 184
 185         mutex_lock(&indio_dev->mlock);
 186         gpio_set_value(st->pdata->gpio_os0, (ret >> 0) & 1);
 187         gpio_set_value(st->pdata->gpio_os1, (ret >> 1) & 1);
 188         gpio_set_value(st->pdata->gpio_os1, (ret >> 2) & 1);
 189         st->oversampling = lval;
 190         mutex_unlock(&indio_dev->mlock);
 191
 192         return count;
 193 }
 194
 195 static IIO_DEVICE_ATTR(oversampling_ratio, S_IRUGO | S_IWUSR,
 196                        ad7606_show_oversampling_ratio,
 197                        ad7606_store_oversampling_ratio, 0);
 198 static IIO_CONST_ATTR(oversampling_ratio_available, "0 2 4 8 16 32 64");
 199
 200 static struct attribute *ad7606_attributes_os_and_range[] = {
 201         &iio_dev_attr_in_voltage_range.dev_attr.attr,
 202         &iio_const_attr_in_voltage_range_available.dev_attr.attr,
 203         &iio_dev_attr_oversampling_ratio.dev_attr.attr,
 204         &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
 205         NULL,
 206 };
 207
 208 static const struct attribute_group ad7606_attribute_group_os_and_range = {
 209         .attrs = ad7606_attributes_os_and_range,
 210 };
 211
 212 static struct attribute *ad7606_attributes_os[] = {
 213         &iio_dev_attr_oversampling_ratio.dev_attr.attr,
 214         &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
 215         NULL,
 216 };
 217
 218 static const struct attribute_group ad7606_attribute_group_os = {
 219         .attrs = ad7606_attributes_os,
 220 };
 221
 222 static struct attribute *ad7606_attributes_range[] = {
 223         &iio_dev_attr_in_voltage_range.dev_attr.attr,
 224         &iio_const_attr_in_voltage_range_available.dev_attr.attr,
 225         NULL,
 226 };
 227
 228 static const struct attribute_group ad7606_attribute_group_range = {
 229         .attrs = ad7606_attributes_range,
 230 };
 231
 232 #define AD7606_CHANNEL(num)                                     \
 233         {                                                       \
 234                 .type = IIO_VOLTAGE,                            \
 235                 .indexed = 1,                                   \
 236                 .channel = num,                                 \
 237                 .address = num,                                 \
 238                 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |   \
 239                                 IIO_CHAN_INFO_SCALE_SHARED_BIT, \
 240                 .scan_index = num,                              \
 241                 .scan_type = IIO_ST('s', 16, 16, 0),            \
 242         }
 243
 244 static struct iio_chan_spec ad7606_8_channels[] = {
 245         AD7606_CHANNEL(0),
 246         AD7606_CHANNEL(1),
 247         AD7606_CHANNEL(2),
 248         AD7606_CHANNEL(3),
 249         AD7606_CHANNEL(4),
 250         AD7606_CHANNEL(5),
 251         AD7606_CHANNEL(6),
 252         AD7606_CHANNEL(7),
 253         IIO_CHAN_SOFT_TIMESTAMP(8),
 254 };
 255
 256 static struct iio_chan_spec ad7606_6_channels[] = {
 257         AD7606_CHANNEL(0),
 258         AD7606_CHANNEL(1),
 259         AD7606_CHANNEL(2),
 260         AD7606_CHANNEL(3),
 261         AD7606_CHANNEL(4),
 262         AD7606_CHANNEL(5),
 263         IIO_CHAN_SOFT_TIMESTAMP(6),
 264 };
 265
 266 static struct iio_chan_spec ad7606_4_channels[] = {
 267         AD7606_CHANNEL(0),
 268         AD7606_CHANNEL(1),
 269         AD7606_CHANNEL(2),
 270         AD7606_CHANNEL(3),
 271         IIO_CHAN_SOFT_TIMESTAMP(4),
 272 };
 273
 274 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
 275         /*
 276          * More devices added in future
 277          */
 278         [ID_AD7606_8] = {
 279                 .name = "ad7606",
 280                 .int_vref_mv = 2500,
 281                 .channels = ad7606_8_channels,
 282                 .num_channels = 8,
 283         },
 284         [ID_AD7606_6] = {
 285                 .name = "ad7606-6",
 286                 .int_vref_mv = 2500,
 287                 .channels = ad7606_6_channels,
 288                 .num_channels = 6,
 289         },
 290         [ID_AD7606_4] = {
 291                 .name = "ad7606-4",
 292                 .int_vref_mv = 2500,
 293                 .channels = ad7606_4_channels,
 294                 .num_channels = 4,
 295         },
 296 };
 297
 298 static int ad7606_request_gpios(struct ad7606_state *st)
 299 {
 300         struct gpio gpio_array[3] = {
 301                 [0] = {
 302                         .gpio =  st->pdata->gpio_os0,
 303                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 1) ?
 304                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 305                         .label = "AD7606_OS0",
 306                 },
 307                 [1] = {
 308                         .gpio =  st->pdata->gpio_os1,
 309                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 2) ?
 310                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 311                         .label = "AD7606_OS1",
 312                 },
 313                 [2] = {
 314                         .gpio =  st->pdata->gpio_os2,
 315                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 4) ?
 316                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 317                         .label = "AD7606_OS2",
 318                 },
 319         };
 320         int ret;
 321
 322         if (gpio_is_valid(st->pdata->gpio_convst)) {
 323                 ret = gpio_request_one(st->pdata->gpio_convst,
 324                                        GPIOF_OUT_INIT_LOW,
 325                                        "AD7606_CONVST");
 326                 if (ret) {
 327                         dev_err(st->dev, "failed to request GPIO CONVST\n");
 328                         goto error_ret;
 329                 }
 330         } else {
 331                 ret = -EIO;
 332                 goto error_ret;
 333         }
 334
 335         if (gpio_is_valid(st->pdata->gpio_os0) &&
 336             gpio_is_valid(st->pdata->gpio_os1) &&
 337             gpio_is_valid(st->pdata->gpio_os2)) {
 338                 ret = gpio_request_array(gpio_array, ARRAY_SIZE(gpio_array));
 339                 if (ret < 0)
 340                         goto error_free_convst;
 341         }
 342
 343         if (gpio_is_valid(st->pdata->gpio_reset)) {
 344                 ret = gpio_request_one(st->pdata->gpio_reset,
 345                                        GPIOF_OUT_INIT_LOW,
 346                                        "AD7606_RESET");
 347                 if (ret < 0)
 348                         goto error_free_os;
 349         }
 350
 351         if (gpio_is_valid(st->pdata->gpio_range)) {
 352                 ret = gpio_request_one(st->pdata->gpio_range, GPIOF_DIR_OUT |
 353                                        ((st->range == 10000) ? GPIOF_INIT_HIGH :
 354                                         GPIOF_INIT_LOW), "AD7606_RANGE");
 355                 if (ret < 0)
 356                         goto error_free_reset;
 357         }
 358         if (gpio_is_valid(st->pdata->gpio_stby)) {
 359                 ret = gpio_request_one(st->pdata->gpio_stby,
 360                                        GPIOF_OUT_INIT_HIGH,
 361                                        "AD7606_STBY");
 362                 if (ret < 0)
 363                         goto error_free_range;
 364         }
 365
 366         if (gpio_is_valid(st->pdata->gpio_frstdata)) {
 367                 ret = gpio_request_one(st->pdata->gpio_frstdata, GPIOF_IN,
 368                                        "AD7606_FRSTDATA");
 369                 if (ret < 0)
 370                         goto error_free_stby;
 371         }
 372
 373         return 0;
 374
 375 error_free_stby:
 376         if (gpio_is_valid(st->pdata->gpio_stby))
 377                 gpio_free(st->pdata->gpio_stby);
 378 error_free_range:
 379         if (gpio_is_valid(st->pdata->gpio_range))
 380                 gpio_free(st->pdata->gpio_range);
 381 error_free_reset:
 382         if (gpio_is_valid(st->pdata->gpio_reset))
 383                 gpio_free(st->pdata->gpio_reset);
 384 error_free_os:
 385         if (gpio_is_valid(st->pdata->gpio_os0) &&
 386             gpio_is_valid(st->pdata->gpio_os1) &&
 387             gpio_is_valid(st->pdata->gpio_os2))
 388                 gpio_free_array(gpio_array, ARRAY_SIZE(gpio_array));
 389 error_free_convst:
 390         gpio_free(st->pdata->gpio_convst);
 391 error_ret:
 392         return ret;
 393 }
 394
 395 static void ad7606_free_gpios(struct ad7606_state *st)
 396 {
 397         if (gpio_is_valid(st->pdata->gpio_frstdata))
 398                 gpio_free(st->pdata->gpio_frstdata);
 399         if (gpio_is_valid(st->pdata->gpio_stby))
 400                 gpio_free(st->pdata->gpio_stby);
 401         if (gpio_is_valid(st->pdata->gpio_range))
 402                 gpio_free(st->pdata->gpio_range);
 403         if (gpio_is_valid(st->pdata->gpio_reset))
 404                 gpio_free(st->pdata->gpio_reset);
 405         if (gpio_is_valid(st->pdata->gpio_os0) &&
 406             gpio_is_valid(st->pdata->gpio_os1) &&
 407             gpio_is_valid(st->pdata->gpio_os2)) {
 408                 gpio_free(st->pdata->gpio_os2);
 409                 gpio_free(st->pdata->gpio_os1);
 410                 gpio_free(st->pdata->gpio_os0);
 411         }
 412         gpio_free(st->pdata->gpio_convst);
 413 }
 414
 415 /**
 416  *  Interrupt handler
 417  */
 418 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
 419 {
 420         struct iio_dev *indio_dev = dev_id;
 421         struct ad7606_state *st = iio_priv(indio_dev);
 422
 423         if (iio_buffer_enabled(indio_dev)) {
 424                 if (!work_pending(&st->poll_work))
 425                         schedule_work(&st->poll_work);
 426         } else {
 427                 st->done = true;
 428                 wake_up_interruptible(&st->wq_data_avail);
 429         }
 430
 431         return IRQ_HANDLED;
 432 };
 433
 434 static const struct iio_info ad7606_info_no_os_or_range = {
 435         .driver_module = THIS_MODULE,
 436         .read_raw = &ad7606_read_raw,
 437 };
 438
 439 static const struct iio_info ad7606_info_os_and_range = {
 440         .driver_module = THIS_MODULE,
 441         .read_raw = &ad7606_read_raw,
 442         .attrs = &ad7606_attribute_group_os_and_range,
 443 };
 444
 445 static const struct iio_info ad7606_info_os = {
 446         .driver_module = THIS_MODULE,
 447         .read_raw = &ad7606_read_raw,
 448         .attrs = &ad7606_attribute_group_os,
 449 };
 450
 451 static const struct iio_info ad7606_info_range = {
 452         .driver_module = THIS_MODULE,
 453         .read_raw = &ad7606_read_raw,
 454         .attrs = &ad7606_attribute_group_range,
 455 };
 456
 457 struct iio_dev *ad7606_probe(struct device *dev, int irq,
 458                               void __iomem *base_address,
 459                               unsigned id,
 460                               const struct ad7606_bus_ops *bops)
 461 {
 462         struct ad7606_platform_data *pdata = dev->platform_data;
 463         struct ad7606_state *st;
 464         int ret;
 465         struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
 466
 467         if (indio_dev == NULL) {
 468                 ret = -ENOMEM;
 469                 goto error_ret;
 470         }
 471
 472         st = iio_priv(indio_dev);
 473
 474         st->dev = dev;
 475         st->bops = bops;
 476         st->base_address = base_address;
 477         st->range = pdata->default_range == 10000 ? 10000 : 5000;
 478
 479         ret = ad7606_oversampling_get_index(pdata->default_os);
 480         if (ret < 0) {
 481                 dev_warn(dev, "oversampling %d is not supported\n",
 482                          pdata->default_os);
 483                 st->oversampling = 0;
 484         } else {
 485                 st->oversampling = pdata->default_os;
 486         }
 487
 488         st->reg = regulator_get(dev, "vcc");
 489         if (!IS_ERR(st->reg)) {
 490                 ret = regulator_enable(st->reg);
 491                 if (ret)
 492                         goto error_put_reg;
 493         }
 494
 495         st->pdata = pdata;
 496         st->chip_info = &ad7606_chip_info_tbl[id];
 497
 498         indio_dev->dev.parent = dev;
 499         if (gpio_is_valid(st->pdata->gpio_os0) &&
 500             gpio_is_valid(st->pdata->gpio_os1) &&
 501             gpio_is_valid(st->pdata->gpio_os2)) {
 502                 if (gpio_is_valid(st->pdata->gpio_range))
 503                         indio_dev->info = &ad7606_info_os_and_range;
 504                 else
 505                         indio_dev->info = &ad7606_info_os;
 506         } else {
 507                 if (gpio_is_valid(st->pdata->gpio_range))
 508                         indio_dev->info = &ad7606_info_range;
 509                 else
 510                         indio_dev->info = &ad7606_info_no_os_or_range;
 511         }
 512         indio_dev->modes = INDIO_DIRECT_MODE;
 513         indio_dev->name = st->chip_info->name;
 514         indio_dev->channels = st->chip_info->channels;
 515         indio_dev->num_channels = st->chip_info->num_channels;
 516
 517         init_waitqueue_head(&st->wq_data_avail);
 518
 519         ret = ad7606_request_gpios(st);
 520         if (ret)
 521                 goto error_disable_reg;
 522
 523         ret = ad7606_reset(st);
 524         if (ret)
 525                 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
 526
 527         ret = request_irq(irq, ad7606_interrupt,
 528                 IRQF_TRIGGER_FALLING, st->chip_info->name, indio_dev);
 529         if (ret)
 530                 goto error_free_gpios;
 531
 532         ret = ad7606_register_ring_funcs_and_init(indio_dev);
 533         if (ret)
 534                 goto error_free_irq;
 535
 536         ret = iio_buffer_register(indio_dev,
 537                                   indio_dev->channels,
 538                                   indio_dev->num_channels);
 539         if (ret)
 540                 goto error_cleanup_ring;
 541         ret = iio_device_register(indio_dev);
 542         if (ret)
 543                 goto error_unregister_ring;
 544
 545         return indio_dev;
 546 error_unregister_ring:
 547         iio_buffer_unregister(indio_dev);
 548
 549 error_cleanup_ring:
 550         ad7606_ring_cleanup(indio_dev);
 551
 552 error_free_irq:
 553         free_irq(irq, indio_dev);
 554
 555 error_free_gpios:
 556         ad7606_free_gpios(st);
 557
 558 error_disable_reg:
 559         if (!IS_ERR(st->reg))
 560                 regulator_disable(st->reg);
 561 error_put_reg:
 562         if (!IS_ERR(st->reg))
 563                 regulator_put(st->reg);
 564         iio_device_free(indio_dev);
 565 error_ret:
 566         return ERR_PTR(ret);
 567 }
 568
 569 int ad7606_remove(struct iio_dev *indio_dev, int irq)
 570 {
 571         struct ad7606_state *st = iio_priv(indio_dev);
 572
 573         iio_device_unregister(indio_dev);
 574         iio_buffer_unregister(indio_dev);
 575         ad7606_ring_cleanup(indio_dev);
 576
 577         free_irq(irq, indio_dev);
 578         if (!IS_ERR(st->reg)) {
 579                 regulator_disable(st->reg);
 580                 regulator_put(st->reg);
 581         }
 582
 583         ad7606_free_gpios(st);
 584         iio_device_free(indio_dev);
 585
 586         return 0;
 587 }
 588
 589 void ad7606_suspend(struct iio_dev *indio_dev)
 590 {
 591         struct ad7606_state *st = iio_priv(indio_dev);
 592
 593         if (gpio_is_valid(st->pdata->gpio_stby)) {
 594                 if (gpio_is_valid(st->pdata->gpio_range))
 595                         gpio_set_value(st->pdata->gpio_range, 1);
 596                 gpio_set_value(st->pdata->gpio_stby, 0);
 597         }
 598 }
 599
 600 void ad7606_resume(struct iio_dev *indio_dev)
 601 {
 602         struct ad7606_state *st = iio_priv(indio_dev);
 603
 604         if (gpio_is_valid(st->pdata->gpio_stby)) {
 605                 if (gpio_is_valid(st->pdata->gpio_range))
 606                         gpio_set_value(st->pdata->gpio_range,
 607                                         st->range == 10000);
 608
 609                 gpio_set_value(st->pdata->gpio_stby, 1);
 610                 ad7606_reset(st);
 611         }
 612 }
 613
 614 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 615 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 616 MODULE_LICENSE("GPL v2");