linux/drivers/iio/dac/ad5770r.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * AD5770R Digital to analog converters driver
   4 *
   5 * Copyright 2018 Analog Devices Inc.
   6 */
   7
   8#include <linux/bits.h>
   9#include <linux/delay.h>
  10#include <linux/device.h>
  11#include <linux/gpio/consumer.h>
  12#include <linux/iio/iio.h>
  13#include <linux/iio/sysfs.h>
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/property.h>
  17#include <linux/regmap.h>
  18#include <linux/regulator/consumer.h>
  19#include <linux/spi/spi.h>
  20
  21#define ADI_SPI_IF_CONFIG_A             0x00
  22#define ADI_SPI_IF_CONFIG_B             0x01
  23#define ADI_SPI_IF_DEVICE_CONFIG        0x02
  24#define ADI_SPI_IF_CHIP_TYPE            0x03
  25#define ADI_SPI_IF_PRODUCT_ID_L         0x04
  26#define ADI_SPI_IF_PRODUCT_ID_H         0x05
  27#define ADI_SPI_IF_CHIP_GRADE           0x06
  28#define ADI_SPI_IF_SCRACTH_PAD          0x0A
  29#define ADI_SPI_IF_SPI_REVISION         0x0B
  30#define ADI_SPI_IF_SPI_VENDOR_L         0x0C
  31#define ADI_SPI_IF_SPI_VENDOR_H         0x0D
  32#define ADI_SPI_IF_SPI_STREAM_MODE      0x0E
  33#define ADI_SPI_IF_CONFIG_C             0x10
  34#define ADI_SPI_IF_STATUS_A             0x11
  35
  36/* ADI_SPI_IF_CONFIG_A */
  37#define ADI_SPI_IF_SW_RESET_MSK         (BIT(0) | BIT(7))
  38#define ADI_SPI_IF_SW_RESET_SEL(x)      ((x) & ADI_SPI_IF_SW_RESET_MSK)
  39#define ADI_SPI_IF_ADDR_ASC_MSK         (BIT(2) | BIT(5))
  40#define ADI_SPI_IF_ADDR_ASC_SEL(x)      (((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
  41
  42/* ADI_SPI_IF_CONFIG_B */
  43#define ADI_SPI_IF_SINGLE_INS_MSK       BIT(7)
  44#define ADI_SPI_IF_SINGLE_INS_SEL(x)    FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
  45#define ADI_SPI_IF_SHORT_INS_MSK        BIT(7)
  46#define ADI_SPI_IF_SHORT_INS_SEL(x)     FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
  47
  48/* ADI_SPI_IF_CONFIG_C */
  49#define ADI_SPI_IF_STRICT_REG_MSK       BIT(5)
  50#define ADI_SPI_IF_STRICT_REG_GET(x)    FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
  51
  52/* AD5770R configuration registers */
  53#define AD5770R_CHANNEL_CONFIG          0x14
  54#define AD5770R_OUTPUT_RANGE(ch)        (0x15 + (ch))
  55#define AD5770R_FILTER_RESISTOR(ch)     (0x1D + (ch))
  56#define AD5770R_REFERENCE               0x1B
  57#define AD5770R_DAC_LSB(ch)             (0x26 + 2 * (ch))
  58#define AD5770R_DAC_MSB(ch)             (0x27 + 2 * (ch))
  59#define AD5770R_CH_SELECT               0x34
  60#define AD5770R_CH_ENABLE               0x44
  61
  62/* AD5770R_CHANNEL_CONFIG */
  63#define AD5770R_CFG_CH0_SINK_EN(x)              (((x) & 0x1) << 7)
  64#define AD5770R_CFG_SHUTDOWN_B(x, ch)           (((x) & 0x1) << (ch))
  65
  66/* AD5770R_OUTPUT_RANGE */
  67#define AD5770R_RANGE_OUTPUT_SCALING(x)         (((x) & GENMASK(5, 0)) << 2)
  68#define AD5770R_RANGE_MODE(x)                   ((x) & GENMASK(1, 0))
  69
  70/* AD5770R_REFERENCE */
  71#define AD5770R_REF_RESISTOR_SEL(x)             (((x) & 0x1) << 2)
  72#define AD5770R_REF_SEL(x)                      ((x) & GENMASK(1, 0))
  73
  74/* AD5770R_CH_ENABLE */
  75#define AD5770R_CH_SET(x, ch)           (((x) & 0x1) << (ch))
  76
  77#define AD5770R_MAX_CHANNELS    6
  78#define AD5770R_MAX_CH_MODES    14
  79#define AD5770R_LOW_VREF_mV     1250
  80#define AD5770R_HIGH_VREF_mV    2500
  81
  82enum ad5770r_ch0_modes {
  83        AD5770R_CH0_0_300 = 0,
  84        AD5770R_CH0_NEG_60_0,
  85        AD5770R_CH0_NEG_60_300
  86};
  87
  88enum ad5770r_ch1_modes {
  89        AD5770R_CH1_0_140_LOW_HEAD = 1,
  90        AD5770R_CH1_0_140_LOW_NOISE,
  91        AD5770R_CH1_0_250
  92};
  93
  94enum ad5770r_ch2_5_modes {
  95        AD5770R_CH_LOW_RANGE = 0,
  96        AD5770R_CH_HIGH_RANGE
  97};
  98
  99enum ad5770r_ref_v {
 100        AD5770R_EXT_2_5_V = 0,
 101        AD5770R_INT_1_25_V_OUT_ON,
 102        AD5770R_EXT_1_25_V,
 103        AD5770R_INT_1_25_V_OUT_OFF
 104};
 105
 106enum ad5770r_output_filter_resistor {
 107        AD5770R_FILTER_60_OHM = 0x0,
 108        AD5770R_FILTER_5_6_KOHM = 0x5,
 109        AD5770R_FILTER_11_2_KOHM,
 110        AD5770R_FILTER_22_2_KOHM,
 111        AD5770R_FILTER_44_4_KOHM,
 112        AD5770R_FILTER_104_KOHM,
 113};
 114
 115struct ad5770r_out_range {
 116        u8      out_scale;
 117        u8      out_range_mode;
 118};
 119
 120/**
 121 * struct ad5770r_state - driver instance specific data
 122 * @spi:                spi_device
 123 * @regmap:             regmap
 124 * @vref_reg:           fixed regulator for reference configuration
 125 * @gpio_reset:         gpio descriptor
 126 * @output_mode:        array contains channels output ranges
 127 * @vref:               reference value
 128 * @ch_pwr_down:        powerdown flags
 129 * @internal_ref:       internal reference flag
 130 * @external_res:       external 2.5k resistor flag
 131 * @transf_buf:         cache aligned buffer for spi read/write
 132 */
 133struct ad5770r_state {
 134        struct spi_device               *spi;
 135        struct regmap                   *regmap;
 136        struct regulator                *vref_reg;
 137        struct gpio_desc                *gpio_reset;
 138        struct ad5770r_out_range        output_mode[AD5770R_MAX_CHANNELS];
 139        int                             vref;
 140        bool                            ch_pwr_down[AD5770R_MAX_CHANNELS];
 141        bool                            internal_ref;
 142        bool                            external_res;
 143        u8                              transf_buf[2] ____cacheline_aligned;
 144};
 145
 146static const struct regmap_config ad5770r_spi_regmap_config = {
 147        .reg_bits = 8,
 148        .val_bits = 8,
 149        .read_flag_mask = BIT(7),
 150};
 151
 152struct ad5770r_output_modes {
 153        unsigned int ch;
 154        u8 mode;
 155        int min;
 156        int max;
 157};
 158
 159static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
 160        { 0, AD5770R_CH0_0_300, 0, 300 },
 161        { 0, AD5770R_CH0_NEG_60_0, -60, 0 },
 162        { 0, AD5770R_CH0_NEG_60_300, -60, 300 },
 163        { 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
 164        { 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
 165        { 1, AD5770R_CH1_0_250, 0, 250 },
 166        { 2, AD5770R_CH_LOW_RANGE, 0, 55 },
 167        { 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
 168        { 3, AD5770R_CH_LOW_RANGE, 0, 45 },
 169        { 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
 170        { 4, AD5770R_CH_LOW_RANGE, 0, 45 },
 171        { 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
 172        { 5, AD5770R_CH_LOW_RANGE, 0, 45 },
 173        { 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
 174};
 175
 176static const unsigned int ad5770r_filter_freqs[] = {
 177        153, 357, 715, 1400, 2800, 262000,
 178};
 179
 180static const unsigned int ad5770r_filter_reg_vals[] = {
 181        AD5770R_FILTER_104_KOHM,
 182        AD5770R_FILTER_44_4_KOHM,
 183        AD5770R_FILTER_22_2_KOHM,
 184        AD5770R_FILTER_11_2_KOHM,
 185        AD5770R_FILTER_5_6_KOHM,
 186        AD5770R_FILTER_60_OHM
 187};
 188
 189static int ad5770r_set_output_mode(struct ad5770r_state *st,
 190                                   const struct ad5770r_out_range *out_mode,
 191                                   int channel)
 192{
 193        unsigned int regval;
 194
 195        regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
 196                 AD5770R_RANGE_MODE(out_mode->out_range_mode);
 197
 198        return regmap_write(st->regmap,
 199                            AD5770R_OUTPUT_RANGE(channel), regval);
 200}
 201
 202static int ad5770r_set_reference(struct ad5770r_state *st)
 203{
 204        unsigned int regval;
 205
 206        regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
 207
 208        if (st->internal_ref) {
 209                regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
 210        } else {
 211                switch (st->vref) {
 212                case AD5770R_LOW_VREF_mV:
 213                        regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
 214                        break;
 215                case AD5770R_HIGH_VREF_mV:
 216                        regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
 217                        break;
 218                default:
 219                        regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
 220                        break;
 221                }
 222        }
 223
 224        return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
 225}
 226
 227static int ad5770r_soft_reset(struct ad5770r_state *st)
 228{
 229        return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
 230                            ADI_SPI_IF_SW_RESET_SEL(1));
 231}
 232
 233static int ad5770r_reset(struct ad5770r_state *st)
 234{
 235        /* Perform software reset if no GPIO provided */
 236        if (!st->gpio_reset)
 237                return ad5770r_soft_reset(st);
 238
 239        gpiod_set_value_cansleep(st->gpio_reset, 0);
 240        usleep_range(10, 20);
 241        gpiod_set_value_cansleep(st->gpio_reset, 1);
 242
 243        /* data must not be written during reset timeframe */
 244        usleep_range(100, 200);
 245
 246        return 0;
 247}
 248
 249static int ad5770r_get_range(struct ad5770r_state *st,
 250                             int ch, int *min, int *max)
 251{
 252        int i;
 253        u8 tbl_ch, tbl_mode, out_range;
 254
 255        out_range = st->output_mode[ch].out_range_mode;
 256
 257        for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
 258                tbl_ch = ad5770r_rng_tbl[i].ch;
 259                tbl_mode = ad5770r_rng_tbl[i].mode;
 260                if (tbl_ch == ch && tbl_mode == out_range) {
 261                        *min = ad5770r_rng_tbl[i].min;
 262                        *max = ad5770r_rng_tbl[i].max;
 263                        return 0;
 264                }
 265        }
 266
 267        return -EINVAL;
 268}
 269
 270static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
 271                                   const struct iio_chan_spec *chan, int *freq)
 272{
 273        struct ad5770r_state *st = iio_priv(indio_dev);
 274        int ret;
 275        unsigned int regval, i;
 276
 277        ret = regmap_read(st->regmap,
 278                          AD5770R_FILTER_RESISTOR(chan->channel), &regval);
 279        if (ret < 0)
 280                return ret;
 281
 282        for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
 283                if (regval == ad5770r_filter_reg_vals[i])
 284                        break;
 285        if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
 286                return -EINVAL;
 287
 288        *freq = ad5770r_filter_freqs[i];
 289
 290        return IIO_VAL_INT;
 291}
 292
 293static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
 294                                   const struct iio_chan_spec *chan,
 295                                   unsigned int freq)
 296{
 297        struct ad5770r_state *st = iio_priv(indio_dev);
 298        unsigned int regval, i;
 299
 300        for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
 301                if (ad5770r_filter_freqs[i] >= freq)
 302                        break;
 303        if (i == ARRAY_SIZE(ad5770r_filter_freqs))
 304                return -EINVAL;
 305
 306        regval = ad5770r_filter_reg_vals[i];
 307
 308        return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
 309                            regval);
 310}
 311
 312static int ad5770r_read_raw(struct iio_dev *indio_dev,
 313                            struct iio_chan_spec const *chan,
 314                            int *val, int *val2, long info)
 315{
 316        struct ad5770r_state *st = iio_priv(indio_dev);
 317        int max, min, ret;
 318        u16 buf16;
 319
 320        switch (info) {
 321        case IIO_CHAN_INFO_RAW:
 322                ret = regmap_bulk_read(st->regmap,
 323                                       chan->address,
 324                                       st->transf_buf, 2);
 325                if (ret)
 326                        return 0;
 327
 328                buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
 329                *val = buf16 >> 2;
 330                return IIO_VAL_INT;
 331        case IIO_CHAN_INFO_SCALE:
 332                ret = ad5770r_get_range(st, chan->channel, &min, &max);
 333                if (ret < 0)
 334                        return ret;
 335                *val = max - min;
 336                /* There is no sign bit. (negative current is mapped from 0)
 337                 * (sourced/sinked) current = raw * scale + offset
 338                 * where offset in case of CH0 can be negative.
 339                 */
 340                *val2 = 14;
 341                return IIO_VAL_FRACTIONAL_LOG2;
 342        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 343                return ad5770r_get_filter_freq(indio_dev, chan, val);
 344        case IIO_CHAN_INFO_OFFSET:
 345                ret = ad5770r_get_range(st, chan->channel, &min, &max);
 346                if (ret < 0)
 347                        return ret;
 348                *val = min;
 349                return IIO_VAL_INT;
 350        default:
 351                return -EINVAL;
 352        }
 353}
 354
 355static int ad5770r_write_raw(struct iio_dev *indio_dev,
 356                             struct iio_chan_spec const *chan,
 357                             int val, int val2, long info)
 358{
 359        struct ad5770r_state *st = iio_priv(indio_dev);
 360
 361        switch (info) {
 362        case IIO_CHAN_INFO_RAW:
 363                st->transf_buf[0] = ((u16)val >> 6);
 364                st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
 365                return regmap_bulk_write(st->regmap, chan->address,
 366                                         st->transf_buf, 2);
 367        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 368                return ad5770r_set_filter_freq(indio_dev, chan, val);
 369        default:
 370                return -EINVAL;
 371        }
 372}
 373
 374static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
 375                                   struct iio_chan_spec const *chan,
 376                                   const int **vals, int *type, int *length,
 377                                   long mask)
 378{
 379        switch (mask) {
 380        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
 381                *type = IIO_VAL_INT;
 382                *vals = ad5770r_filter_freqs;
 383                *length = ARRAY_SIZE(ad5770r_filter_freqs);
 384                return IIO_AVAIL_LIST;
 385        }
 386
 387        return -EINVAL;
 388}
 389
 390static int ad5770r_reg_access(struct iio_dev *indio_dev,
 391                              unsigned int reg,
 392                              unsigned int writeval,
 393                              unsigned int *readval)
 394{
 395        struct ad5770r_state *st = iio_priv(indio_dev);
 396
 397        if (readval)
 398                return regmap_read(st->regmap, reg, readval);
 399        else
 400                return regmap_write(st->regmap, reg, writeval);
 401}
 402
 403static const struct iio_info ad5770r_info = {
 404        .read_raw = ad5770r_read_raw,
 405        .write_raw = ad5770r_write_raw,
 406        .read_avail = ad5770r_read_freq_avail,
 407        .debugfs_reg_access = &ad5770r_reg_access,
 408};
 409
 410static int ad5770r_store_output_range(struct ad5770r_state *st,
 411                                      int min, int max, int index)
 412{
 413        int i;
 414
 415        for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
 416                if (ad5770r_rng_tbl[i].ch != index)
 417                        continue;
 418                if (ad5770r_rng_tbl[i].min != min ||
 419                    ad5770r_rng_tbl[i].max != max)
 420                        continue;
 421                st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
 422
 423                return 0;
 424        }
 425
 426        return -EINVAL;
 427}
 428
 429static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
 430                                          uintptr_t private,
 431                                          const struct iio_chan_spec *chan,
 432                                          char *buf)
 433{
 434        struct ad5770r_state *st = iio_priv(indio_dev);
 435
 436        return sysfs_emit(buf, "%d\n", st->ch_pwr_down[chan->channel]);
 437}
 438
 439static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
 440                                           uintptr_t private,
 441                                           const struct iio_chan_spec *chan,
 442                                           const char *buf, size_t len)
 443{
 444        struct ad5770r_state *st = iio_priv(indio_dev);
 445        unsigned int regval;
 446        unsigned int mask;
 447        bool readin;
 448        int ret;
 449
 450        ret = kstrtobool(buf, &readin);
 451        if (ret)
 452                return ret;
 453
 454        readin = !readin;
 455
 456        regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
 457        if (chan->channel == 0 &&
 458            st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
 459                regval |= AD5770R_CFG_CH0_SINK_EN(readin);
 460                mask = BIT(chan->channel) + BIT(7);
 461        } else {
 462                mask = BIT(chan->channel);
 463        }
 464        ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
 465                                 regval);
 466        if (ret)
 467                return ret;
 468
 469        regval = AD5770R_CH_SET(readin, chan->channel);
 470        ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
 471                                 BIT(chan->channel), regval);
 472        if (ret)
 473                return ret;
 474
 475        st->ch_pwr_down[chan->channel] = !readin;
 476
 477        return len;
 478}
 479
 480static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
 481        {
 482                .name = "powerdown",
 483                .read = ad5770r_read_dac_powerdown,
 484                .write = ad5770r_write_dac_powerdown,
 485                .shared = IIO_SEPARATE,
 486        },
 487        { }
 488};
 489
 490#define AD5770R_IDAC_CHANNEL(index, reg) {                              \
 491        .type = IIO_CURRENT,                                            \
 492        .address = reg,                                                 \
 493        .indexed = 1,                                                   \
 494        .channel = index,                                               \
 495        .output = 1,                                                    \
 496        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |                  \
 497                BIT(IIO_CHAN_INFO_SCALE) |                              \
 498                BIT(IIO_CHAN_INFO_OFFSET) |                             \
 499                BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),       \
 500        .info_mask_shared_by_type_available =                           \
 501                BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),       \
 502        .ext_info = ad5770r_ext_info,                                   \
 503}
 504
 505static const struct iio_chan_spec ad5770r_channels[] = {
 506        AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
 507        AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
 508        AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
 509        AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
 510        AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
 511        AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
 512};
 513
 514static int ad5770r_channel_config(struct ad5770r_state *st)
 515{
 516        int ret, tmp[2], min, max;
 517        unsigned int num;
 518        struct fwnode_handle *child;
 519
 520        num = device_get_child_node_count(&st->spi->dev);
 521        if (num != AD5770R_MAX_CHANNELS)
 522                return -EINVAL;
 523
 524        device_for_each_child_node(&st->spi->dev, child) {
 525                ret = fwnode_property_read_u32(child, "num", &num);
 526                if (ret)
 527                        goto err_child_out;
 528                if (num >= AD5770R_MAX_CHANNELS) {
 529                        ret = -EINVAL;
 530                        goto err_child_out;
 531                }
 532
 533                ret = fwnode_property_read_u32_array(child,
 534                                                     "adi,range-microamp",
 535                                                     tmp, 2);
 536                if (ret)
 537                        goto err_child_out;
 538
 539                min = tmp[0] / 1000;
 540                max = tmp[1] / 1000;
 541                ret = ad5770r_store_output_range(st, min, max, num);
 542                if (ret)
 543                        goto err_child_out;
 544        }
 545
 546        return 0;
 547
 548err_child_out:
 549        fwnode_handle_put(child);
 550        return ret;
 551}
 552
 553static int ad5770r_init(struct ad5770r_state *st)
 554{
 555        int ret, i;
 556
 557        st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
 558                                                 GPIOD_OUT_HIGH);
 559        if (IS_ERR(st->gpio_reset))
 560                return PTR_ERR(st->gpio_reset);
 561
 562        /* Perform a reset */
 563        ret = ad5770r_reset(st);
 564        if (ret)
 565                return ret;
 566
 567        /* Set output range */
 568        ret = ad5770r_channel_config(st);
 569        if (ret)
 570                return ret;
 571
 572        for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
 573                ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
 574                if (ret)
 575                        return ret;
 576        }
 577
 578        st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
 579                                                     "adi,external-resistor");
 580
 581        ret = ad5770r_set_reference(st);
 582        if (ret)
 583                return ret;
 584
 585        /* Set outputs off */
 586        ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
 587        if (ret)
 588                return ret;
 589
 590        ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
 591        if (ret)
 592                return ret;
 593
 594        for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
 595                st->ch_pwr_down[i] = true;
 596
 597        return ret;
 598}
 599
 600static void ad5770r_disable_regulator(void *data)
 601{
 602        struct ad5770r_state *st = data;
 603
 604        regulator_disable(st->vref_reg);
 605}
 606
 607static int ad5770r_probe(struct spi_device *spi)
 608{
 609        struct ad5770r_state *st;
 610        struct iio_dev *indio_dev;
 611        struct regmap *regmap;
 612        int ret;
 613
 614        indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 615        if (!indio_dev)
 616                return -ENOMEM;
 617
 618        st = iio_priv(indio_dev);
 619        spi_set_drvdata(spi, indio_dev);
 620
 621        st->spi = spi;
 622
 623        regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
 624        if (IS_ERR(regmap)) {
 625                dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
 626                        PTR_ERR(regmap));
 627                return PTR_ERR(regmap);
 628        }
 629        st->regmap = regmap;
 630
 631        st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
 632        if (!IS_ERR(st->vref_reg)) {
 633                ret = regulator_enable(st->vref_reg);
 634                if (ret) {
 635                        dev_err(&spi->dev,
 636                                "Failed to enable vref regulators: %d\n", ret);
 637                        return ret;
 638                }
 639
 640                ret = devm_add_action_or_reset(&spi->dev,
 641                                               ad5770r_disable_regulator,
 642                                               st);
 643                if (ret < 0)
 644                        return ret;
 645
 646                ret = regulator_get_voltage(st->vref_reg);
 647                if (ret < 0)
 648                        return ret;
 649
 650                st->vref = ret / 1000;
 651        } else {
 652                if (PTR_ERR(st->vref_reg) == -ENODEV) {
 653                        st->vref = AD5770R_LOW_VREF_mV;
 654                        st->internal_ref = true;
 655                } else {
 656                        return PTR_ERR(st->vref_reg);
 657                }
 658        }
 659
 660        indio_dev->name = spi_get_device_id(spi)->name;
 661        indio_dev->info = &ad5770r_info;
 662        indio_dev->modes = INDIO_DIRECT_MODE;
 663        indio_dev->channels = ad5770r_channels;
 664        indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
 665
 666        ret = ad5770r_init(st);
 667        if (ret < 0) {
 668                dev_err(&spi->dev, "AD5770R init failed\n");
 669                return ret;
 670        }
 671
 672        return devm_iio_device_register(&st->spi->dev, indio_dev);
 673}
 674
 675static const struct of_device_id ad5770r_of_id[] = {
 676        { .compatible = "adi,ad5770r", },
 677        {},
 678};
 679MODULE_DEVICE_TABLE(of, ad5770r_of_id);
 680
 681static const struct spi_device_id ad5770r_id[] = {
 682        { "ad5770r", 0 },
 683        {},
 684};
 685MODULE_DEVICE_TABLE(spi, ad5770r_id);
 686
 687static struct spi_driver ad5770r_driver = {
 688        .driver = {
 689                .name = KBUILD_MODNAME,
 690                .of_match_table = ad5770r_of_id,
 691        },
 692        .probe = ad5770r_probe,
 693        .id_table = ad5770r_id,
 694};
 695
 696module_spi_driver(ad5770r_driver);
 697
 698MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
 699MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
 700MODULE_LICENSE("GPL v2");
 701