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
  89         switch (m) {
  90         case IIO_CHAN_INFO_RAW:
  91                 mutex_lock(&indio_dev->mlock);
  92                 if (iio_buffer_enabled(indio_dev))
  93                         ret = -EBUSY;
  94                 else
  95                         ret = ad7606_scan_direct(indio_dev, chan->address);
  96                 mutex_unlock(&indio_dev->mlock);
  97
  98                 if (ret < 0)
  99                         return ret;
 100                 *val = (short) ret;
 101                 return IIO_VAL_INT;
 102         case IIO_CHAN_INFO_SCALE:
 103                 *val = st->range * 2;
 104                 *val2 = st->chip_info->channels[0].scan_type.realbits;
 105                 return IIO_VAL_FRACTIONAL_LOG2;
 106         }
 107         return -EINVAL;
 108 }
 109
 110 static ssize_t ad7606_show_range(struct device *dev,
 111                         struct device_attribute *attr, char *buf)
 112 {
 113         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 114         struct ad7606_state *st = iio_priv(indio_dev);
 115
 116         return sprintf(buf, "%u\n", st->range);
 117 }
 118
 119 static ssize_t ad7606_store_range(struct device *dev,
 120                 struct device_attribute *attr, const char *buf, size_t count)
 121 {
 122         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 123         struct ad7606_state *st = iio_priv(indio_dev);
 124         unsigned long lval;
 125         int ret;
 126
 127         ret = kstrtoul(buf, 10, &lval);
 128         if (ret)
 129                 return ret;
 130
 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         ret = kstrtoul(buf, 10, &lval);
 177         if (ret)
 178                 return ret;
 179
 180         ret = ad7606_oversampling_get_index(lval);
 181         if (ret < 0) {
 182                 dev_err(dev, "oversampling %lu is not supported\n", lval);
 183                 return ret;
 184         }
 185
 186         mutex_lock(&indio_dev->mlock);
 187         gpio_set_value(st->pdata->gpio_os0, (ret >> 0) & 1);
 188         gpio_set_value(st->pdata->gpio_os1, (ret >> 1) & 1);
 189         gpio_set_value(st->pdata->gpio_os1, (ret >> 2) & 1);
 190         st->oversampling = lval;
 191         mutex_unlock(&indio_dev->mlock);
 192
 193         return count;
 194 }
 195
 196 static IIO_DEVICE_ATTR(oversampling_ratio, S_IRUGO | S_IWUSR,
 197                        ad7606_show_oversampling_ratio,
 198                        ad7606_store_oversampling_ratio, 0);
 199 static IIO_CONST_ATTR(oversampling_ratio_available, "0 2 4 8 16 32 64");
 200
 201 static struct attribute *ad7606_attributes_os_and_range[] = {
 202         &iio_dev_attr_in_voltage_range.dev_attr.attr,
 203         &iio_const_attr_in_voltage_range_available.dev_attr.attr,
 204         &iio_dev_attr_oversampling_ratio.dev_attr.attr,
 205         &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
 206         NULL,
 207 };
 208
 209 static const struct attribute_group ad7606_attribute_group_os_and_range = {
 210         .attrs = ad7606_attributes_os_and_range,
 211 };
 212
 213 static struct attribute *ad7606_attributes_os[] = {
 214         &iio_dev_attr_oversampling_ratio.dev_attr.attr,
 215         &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
 216         NULL,
 217 };
 218
 219 static const struct attribute_group ad7606_attribute_group_os = {
 220         .attrs = ad7606_attributes_os,
 221 };
 222
 223 static struct attribute *ad7606_attributes_range[] = {
 224         &iio_dev_attr_in_voltage_range.dev_attr.attr,
 225         &iio_const_attr_in_voltage_range_available.dev_attr.attr,
 226         NULL,
 227 };
 228
 229 static const struct attribute_group ad7606_attribute_group_range = {
 230         .attrs = ad7606_attributes_range,
 231 };
 232
 233 #define AD7606_CHANNEL(num)                                     \
 234         {                                                       \
 235                 .type = IIO_VOLTAGE,                            \
 236                 .indexed = 1,                                   \
 237                 .channel = num,                                 \
 238                 .address = num,                                 \
 239                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
 240                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
 241                 .scan_index = num,                              \
 242                 .scan_type = {                                  \
 243                         .sign = 's',                            \
 244                         .realbits = 16,                         \
 245                         .storagebits = 16,                      \
 246                         .endianness = IIO_CPU,                  \
 247                 },                                              \
 248         }
 249
 250 static const struct iio_chan_spec ad7606_8_channels[] = {
 251         AD7606_CHANNEL(0),
 252         AD7606_CHANNEL(1),
 253         AD7606_CHANNEL(2),
 254         AD7606_CHANNEL(3),
 255         AD7606_CHANNEL(4),
 256         AD7606_CHANNEL(5),
 257         AD7606_CHANNEL(6),
 258         AD7606_CHANNEL(7),
 259         IIO_CHAN_SOFT_TIMESTAMP(8),
 260 };
 261
 262 static const struct iio_chan_spec ad7606_6_channels[] = {
 263         AD7606_CHANNEL(0),
 264         AD7606_CHANNEL(1),
 265         AD7606_CHANNEL(2),
 266         AD7606_CHANNEL(3),
 267         AD7606_CHANNEL(4),
 268         AD7606_CHANNEL(5),
 269         IIO_CHAN_SOFT_TIMESTAMP(6),
 270 };
 271
 272 static const struct iio_chan_spec ad7606_4_channels[] = {
 273         AD7606_CHANNEL(0),
 274         AD7606_CHANNEL(1),
 275         AD7606_CHANNEL(2),
 276         AD7606_CHANNEL(3),
 277         IIO_CHAN_SOFT_TIMESTAMP(4),
 278 };
 279
 280 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
 281         /*
 282          * More devices added in future
 283          */
 284         [ID_AD7606_8] = {
 285                 .name = "ad7606",
 286                 .int_vref_mv = 2500,
 287                 .channels = ad7606_8_channels,
 288                 .num_channels = 8,
 289         },
 290         [ID_AD7606_6] = {
 291                 .name = "ad7606-6",
 292                 .int_vref_mv = 2500,
 293                 .channels = ad7606_6_channels,
 294                 .num_channels = 6,
 295         },
 296         [ID_AD7606_4] = {
 297                 .name = "ad7606-4",
 298                 .int_vref_mv = 2500,
 299                 .channels = ad7606_4_channels,
 300                 .num_channels = 4,
 301         },
 302 };
 303
 304 static int ad7606_request_gpios(struct ad7606_state *st)
 305 {
 306         struct gpio gpio_array[3] = {
 307                 [0] = {
 308                         .gpio =  st->pdata->gpio_os0,
 309                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 1) ?
 310                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 311                         .label = "AD7606_OS0",
 312                 },
 313                 [1] = {
 314                         .gpio =  st->pdata->gpio_os1,
 315                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 2) ?
 316                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 317                         .label = "AD7606_OS1",
 318                 },
 319                 [2] = {
 320                         .gpio =  st->pdata->gpio_os2,
 321                         .flags = GPIOF_DIR_OUT | ((st->oversampling & 4) ?
 322                                  GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
 323                         .label = "AD7606_OS2",
 324                 },
 325         };
 326         int ret;
 327
 328         if (gpio_is_valid(st->pdata->gpio_convst)) {
 329                 ret = gpio_request_one(st->pdata->gpio_convst,
 330                                        GPIOF_OUT_INIT_LOW,
 331                                        "AD7606_CONVST");
 332                 if (ret) {
 333                         dev_err(st->dev, "failed to request GPIO CONVST\n");
 334                         goto error_ret;
 335                 }
 336         } else {
 337                 ret = -EIO;
 338                 goto error_ret;
 339         }
 340
 341         if (gpio_is_valid(st->pdata->gpio_os0) &&
 342             gpio_is_valid(st->pdata->gpio_os1) &&
 343             gpio_is_valid(st->pdata->gpio_os2)) {
 344                 ret = gpio_request_array(gpio_array, ARRAY_SIZE(gpio_array));
 345                 if (ret < 0)
 346                         goto error_free_convst;
 347         }
 348
 349         if (gpio_is_valid(st->pdata->gpio_reset)) {
 350                 ret = gpio_request_one(st->pdata->gpio_reset,
 351                                        GPIOF_OUT_INIT_LOW,
 352                                        "AD7606_RESET");
 353                 if (ret < 0)
 354                         goto error_free_os;
 355         }
 356
 357         if (gpio_is_valid(st->pdata->gpio_range)) {
 358                 ret = gpio_request_one(st->pdata->gpio_range, GPIOF_DIR_OUT |
 359                                        ((st->range == 10000) ? GPIOF_INIT_HIGH :
 360                                         GPIOF_INIT_LOW), "AD7606_RANGE");
 361                 if (ret < 0)
 362                         goto error_free_reset;
 363         }
 364         if (gpio_is_valid(st->pdata->gpio_stby)) {
 365                 ret = gpio_request_one(st->pdata->gpio_stby,
 366                                        GPIOF_OUT_INIT_HIGH,
 367                                        "AD7606_STBY");
 368                 if (ret < 0)
 369                         goto error_free_range;
 370         }
 371
 372         if (gpio_is_valid(st->pdata->gpio_frstdata)) {
 373                 ret = gpio_request_one(st->pdata->gpio_frstdata, GPIOF_IN,
 374                                        "AD7606_FRSTDATA");
 375                 if (ret < 0)
 376                         goto error_free_stby;
 377         }
 378
 379         return 0;
 380
 381 error_free_stby:
 382         if (gpio_is_valid(st->pdata->gpio_stby))
 383                 gpio_free(st->pdata->gpio_stby);
 384 error_free_range:
 385         if (gpio_is_valid(st->pdata->gpio_range))
 386                 gpio_free(st->pdata->gpio_range);
 387 error_free_reset:
 388         if (gpio_is_valid(st->pdata->gpio_reset))
 389                 gpio_free(st->pdata->gpio_reset);
 390 error_free_os:
 391         if (gpio_is_valid(st->pdata->gpio_os0) &&
 392             gpio_is_valid(st->pdata->gpio_os1) &&
 393             gpio_is_valid(st->pdata->gpio_os2))
 394                 gpio_free_array(gpio_array, ARRAY_SIZE(gpio_array));
 395 error_free_convst:
 396         gpio_free(st->pdata->gpio_convst);
 397 error_ret:
 398         return ret;
 399 }
 400
 401 static void ad7606_free_gpios(struct ad7606_state *st)
 402 {
 403         if (gpio_is_valid(st->pdata->gpio_frstdata))
 404                 gpio_free(st->pdata->gpio_frstdata);
 405         if (gpio_is_valid(st->pdata->gpio_stby))
 406                 gpio_free(st->pdata->gpio_stby);
 407         if (gpio_is_valid(st->pdata->gpio_range))
 408                 gpio_free(st->pdata->gpio_range);
 409         if (gpio_is_valid(st->pdata->gpio_reset))
 410                 gpio_free(st->pdata->gpio_reset);
 411         if (gpio_is_valid(st->pdata->gpio_os0) &&
 412             gpio_is_valid(st->pdata->gpio_os1) &&
 413             gpio_is_valid(st->pdata->gpio_os2)) {
 414                 gpio_free(st->pdata->gpio_os2);
 415                 gpio_free(st->pdata->gpio_os1);
 416                 gpio_free(st->pdata->gpio_os0);
 417         }
 418         gpio_free(st->pdata->gpio_convst);
 419 }
 420
 421 /**
 422  *  Interrupt handler
 423  */
 424 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
 425 {
 426         struct iio_dev *indio_dev = dev_id;
 427         struct ad7606_state *st = iio_priv(indio_dev);
 428
 429         if (iio_buffer_enabled(indio_dev)) {
 430                 schedule_work(&st->poll_work);
 431         } else {
 432                 st->done = true;
 433                 wake_up_interruptible(&st->wq_data_avail);
 434         }
 435
 436         return IRQ_HANDLED;
 437 };
 438
 439 static const struct iio_info ad7606_info_no_os_or_range = {
 440         .driver_module = THIS_MODULE,
 441         .read_raw = &ad7606_read_raw,
 442 };
 443
 444 static const struct iio_info ad7606_info_os_and_range = {
 445         .driver_module = THIS_MODULE,
 446         .read_raw = &ad7606_read_raw,
 447         .attrs = &ad7606_attribute_group_os_and_range,
 448 };
 449
 450 static const struct iio_info ad7606_info_os = {
 451         .driver_module = THIS_MODULE,
 452         .read_raw = &ad7606_read_raw,
 453         .attrs = &ad7606_attribute_group_os,
 454 };
 455
 456 static const struct iio_info ad7606_info_range = {
 457         .driver_module = THIS_MODULE,
 458         .read_raw = &ad7606_read_raw,
 459         .attrs = &ad7606_attribute_group_range,
 460 };
 461
 462 struct iio_dev *ad7606_probe(struct device *dev, int irq,
 463                               void __iomem *base_address,
 464                               unsigned id,
 465                               const struct ad7606_bus_ops *bops)
 466 {
 467         struct ad7606_platform_data *pdata = dev->platform_data;
 468         struct ad7606_state *st;
 469         int ret;
 470         struct iio_dev *indio_dev;
 471
 472         indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 473         if (!indio_dev)
 474                 return ERR_PTR(-ENOMEM);
 475
 476         st = iio_priv(indio_dev);
 477
 478         st->dev = dev;
 479         st->bops = bops;
 480         st->base_address = base_address;
 481         st->range = pdata->default_range == 10000 ? 10000 : 5000;
 482
 483         ret = ad7606_oversampling_get_index(pdata->default_os);
 484         if (ret < 0) {
 485                 dev_warn(dev, "oversampling %d is not supported\n",
 486                          pdata->default_os);
 487                 st->oversampling = 0;
 488         } else {
 489                 st->oversampling = pdata->default_os;
 490         }
 491
 492         st->reg = devm_regulator_get(dev, "vcc");
 493         if (!IS_ERR(st->reg)) {
 494                 ret = regulator_enable(st->reg);
 495                 if (ret)
 496                         return ERR_PTR(ret);
 497         }
 498
 499         st->pdata = pdata;
 500         st->chip_info = &ad7606_chip_info_tbl[id];
 501
 502         indio_dev->dev.parent = dev;
 503         if (gpio_is_valid(st->pdata->gpio_os0) &&
 504             gpio_is_valid(st->pdata->gpio_os1) &&
 505             gpio_is_valid(st->pdata->gpio_os2)) {
 506                 if (gpio_is_valid(st->pdata->gpio_range))
 507                         indio_dev->info = &ad7606_info_os_and_range;
 508                 else
 509                         indio_dev->info = &ad7606_info_os;
 510         } else {
 511                 if (gpio_is_valid(st->pdata->gpio_range))
 512                         indio_dev->info = &ad7606_info_range;
 513                 else
 514                         indio_dev->info = &ad7606_info_no_os_or_range;
 515         }
 516         indio_dev->modes = INDIO_DIRECT_MODE;
 517         indio_dev->name = st->chip_info->name;
 518         indio_dev->channels = st->chip_info->channels;
 519         indio_dev->num_channels = st->chip_info->num_channels;
 520
 521         init_waitqueue_head(&st->wq_data_avail);
 522
 523         ret = ad7606_request_gpios(st);
 524         if (ret)
 525                 goto error_disable_reg;
 526
 527         ret = ad7606_reset(st);
 528         if (ret)
 529                 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
 530
 531         ret = request_irq(irq, ad7606_interrupt,
 532                 IRQF_TRIGGER_FALLING, st->chip_info->name, indio_dev);
 533         if (ret)
 534                 goto error_free_gpios;
 535
 536         ret = ad7606_register_ring_funcs_and_init(indio_dev);
 537         if (ret)
 538                 goto error_free_irq;
 539
 540         ret = iio_device_register(indio_dev);
 541         if (ret)
 542                 goto error_unregister_ring;
 543
 544         return indio_dev;
 545 error_unregister_ring:
 546         ad7606_ring_cleanup(indio_dev);
 547
 548 error_free_irq:
 549         free_irq(irq, indio_dev);
 550
 551 error_free_gpios:
 552         ad7606_free_gpios(st);
 553
 554 error_disable_reg:
 555         if (!IS_ERR(st->reg))
 556                 regulator_disable(st->reg);
 557         return ERR_PTR(ret);
 558 }
 559
 560 int ad7606_remove(struct iio_dev *indio_dev, int irq)
 561 {
 562         struct ad7606_state *st = iio_priv(indio_dev);
 563
 564         iio_device_unregister(indio_dev);
 565         ad7606_ring_cleanup(indio_dev);
 566
 567         free_irq(irq, indio_dev);
 568         if (!IS_ERR(st->reg))
 569                 regulator_disable(st->reg);
 570
 571         ad7606_free_gpios(st);
 572
 573         return 0;
 574 }
 575
 576 void ad7606_suspend(struct iio_dev *indio_dev)
 577 {
 578         struct ad7606_state *st = iio_priv(indio_dev);
 579
 580         if (gpio_is_valid(st->pdata->gpio_stby)) {
 581                 if (gpio_is_valid(st->pdata->gpio_range))
 582                         gpio_set_value(st->pdata->gpio_range, 1);
 583                 gpio_set_value(st->pdata->gpio_stby, 0);
 584         }
 585 }
 586
 587 void ad7606_resume(struct iio_dev *indio_dev)
 588 {
 589         struct ad7606_state *st = iio_priv(indio_dev);
 590
 591         if (gpio_is_valid(st->pdata->gpio_stby)) {
 592                 if (gpio_is_valid(st->pdata->gpio_range))
 593                         gpio_set_value(st->pdata->gpio_range,
 594                                         st->range == 10000);
 595
 596                 gpio_set_value(st->pdata->gpio_stby, 1);
 597                 ad7606_reset(st);
 598         }
 599 }
 600
 601 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 602 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 603 MODULE_LICENSE("GPL v2");