linux/drivers/iio/adc/ad9467.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Analog Devices AD9467 SPI ADC driver
   4 *
   5 * Copyright 2012-2020 Analog Devices Inc.
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/device.h>
  10#include <linux/kernel.h>
  11#include <linux/slab.h>
  12#include <linux/spi/spi.h>
  13#include <linux/err.h>
  14#include <linux/delay.h>
  15#include <linux/gpio/consumer.h>
  16#include <linux/of_device.h>
  17
  18
  19#include <linux/iio/iio.h>
  20#include <linux/iio/sysfs.h>
  21
  22#include <linux/clk.h>
  23
  24#include <linux/iio/adc/adi-axi-adc.h>
  25
  26/*
  27 * ADI High-Speed ADC common spi interface registers
  28 * See Application-Note AN-877:
  29 *   https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
  30 */
  31
  32#define AN877_ADC_REG_CHIP_PORT_CONF            0x00
  33#define AN877_ADC_REG_CHIP_ID                   0x01
  34#define AN877_ADC_REG_CHIP_GRADE                0x02
  35#define AN877_ADC_REG_CHAN_INDEX                0x05
  36#define AN877_ADC_REG_TRANSFER                  0xFF
  37#define AN877_ADC_REG_MODES                     0x08
  38#define AN877_ADC_REG_TEST_IO                   0x0D
  39#define AN877_ADC_REG_ADC_INPUT                 0x0F
  40#define AN877_ADC_REG_OFFSET                    0x10
  41#define AN877_ADC_REG_OUTPUT_MODE               0x14
  42#define AN877_ADC_REG_OUTPUT_ADJUST             0x15
  43#define AN877_ADC_REG_OUTPUT_PHASE              0x16
  44#define AN877_ADC_REG_OUTPUT_DELAY              0x17
  45#define AN877_ADC_REG_VREF                      0x18
  46#define AN877_ADC_REG_ANALOG_INPUT              0x2C
  47
  48/* AN877_ADC_REG_TEST_IO */
  49#define AN877_ADC_TESTMODE_OFF                  0x0
  50#define AN877_ADC_TESTMODE_MIDSCALE_SHORT       0x1
  51#define AN877_ADC_TESTMODE_POS_FULLSCALE        0x2
  52#define AN877_ADC_TESTMODE_NEG_FULLSCALE        0x3
  53#define AN877_ADC_TESTMODE_ALT_CHECKERBOARD     0x4
  54#define AN877_ADC_TESTMODE_PN23_SEQ             0x5
  55#define AN877_ADC_TESTMODE_PN9_SEQ              0x6
  56#define AN877_ADC_TESTMODE_ONE_ZERO_TOGGLE      0x7
  57#define AN877_ADC_TESTMODE_USER                 0x8
  58#define AN877_ADC_TESTMODE_BIT_TOGGLE           0x9
  59#define AN877_ADC_TESTMODE_SYNC                 0xA
  60#define AN877_ADC_TESTMODE_ONE_BIT_HIGH         0xB
  61#define AN877_ADC_TESTMODE_MIXED_BIT_FREQUENCY  0xC
  62#define AN877_ADC_TESTMODE_RAMP                 0xF
  63
  64/* AN877_ADC_REG_TRANSFER */
  65#define AN877_ADC_TRANSFER_SYNC                 0x1
  66
  67/* AN877_ADC_REG_OUTPUT_MODE */
  68#define AN877_ADC_OUTPUT_MODE_OFFSET_BINARY     0x0
  69#define AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT   0x1
  70#define AN877_ADC_OUTPUT_MODE_GRAY_CODE         0x2
  71
  72/* AN877_ADC_REG_OUTPUT_PHASE */
  73#define AN877_ADC_OUTPUT_EVEN_ODD_MODE_EN       0x20
  74#define AN877_ADC_INVERT_DCO_CLK                0x80
  75
  76/* AN877_ADC_REG_OUTPUT_DELAY */
  77#define AN877_ADC_DCO_DELAY_ENABLE              0x80
  78
  79/*
  80 * Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
  81 */
  82
  83#define CHIPID_AD9265                   0x64
  84#define AD9265_DEF_OUTPUT_MODE          0x40
  85#define AD9265_REG_VREF_MASK            0xC0
  86
  87/*
  88 * Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
  89 */
  90
  91#define CHIPID_AD9434                   0x6A
  92#define AD9434_DEF_OUTPUT_MODE          0x00
  93#define AD9434_REG_VREF_MASK            0xC0
  94
  95/*
  96 * Analog Devices AD9467 16-Bit, 200/250 MSPS ADC
  97 */
  98
  99#define CHIPID_AD9467                   0x50
 100#define AD9467_DEF_OUTPUT_MODE          0x08
 101#define AD9467_REG_VREF_MASK            0x0F
 102
 103enum {
 104        ID_AD9265,
 105        ID_AD9434,
 106        ID_AD9467,
 107};
 108
 109struct ad9467_chip_info {
 110        struct adi_axi_adc_chip_info    axi_adc_info;
 111        unsigned int                    default_output_mode;
 112        unsigned int                    vref_mask;
 113};
 114
 115#define to_ad9467_chip_info(_info)      \
 116        container_of(_info, struct ad9467_chip_info, axi_adc_info)
 117
 118struct ad9467_state {
 119        struct spi_device               *spi;
 120        struct clk                      *clk;
 121        unsigned int                    output_mode;
 122
 123        struct gpio_desc                *pwrdown_gpio;
 124        struct gpio_desc                *reset_gpio;
 125};
 126
 127static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
 128{
 129        unsigned char tbuf[2], rbuf[1];
 130        int ret;
 131
 132        tbuf[0] = 0x80 | (reg >> 8);
 133        tbuf[1] = reg & 0xFF;
 134
 135        ret = spi_write_then_read(spi,
 136                                  tbuf, ARRAY_SIZE(tbuf),
 137                                  rbuf, ARRAY_SIZE(rbuf));
 138
 139        if (ret < 0)
 140                return ret;
 141
 142        return rbuf[0];
 143}
 144
 145static int ad9467_spi_write(struct spi_device *spi, unsigned int reg,
 146                            unsigned int val)
 147{
 148        unsigned char buf[3];
 149
 150        buf[0] = reg >> 8;
 151        buf[1] = reg & 0xFF;
 152        buf[2] = val;
 153
 154        return spi_write(spi, buf, ARRAY_SIZE(buf));
 155}
 156
 157static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
 158                             unsigned int writeval, unsigned int *readval)
 159{
 160        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 161        struct spi_device *spi = st->spi;
 162        int ret;
 163
 164        if (readval == NULL) {
 165                ret = ad9467_spi_write(spi, reg, writeval);
 166                ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
 167                                 AN877_ADC_TRANSFER_SYNC);
 168                return ret;
 169        }
 170
 171        ret = ad9467_spi_read(spi, reg);
 172        if (ret < 0)
 173                return ret;
 174        *readval = ret;
 175
 176        return 0;
 177}
 178
 179static const unsigned int ad9265_scale_table[][2] = {
 180        {1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
 181};
 182
 183static const unsigned int ad9434_scale_table[][2] = {
 184        {1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
 185        {1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
 186        {1340, 0x06}, {1310, 0x07}, {1280, 0x08}, {1260, 0x09}, {1230, 0x0A},
 187        {1200, 0x0B}, {1180, 0x0C},
 188};
 189
 190static const unsigned int ad9467_scale_table[][2] = {
 191        {2000, 0}, {2100, 6}, {2200, 7},
 192        {2300, 8}, {2400, 9}, {2500, 10},
 193};
 194
 195static void __ad9467_get_scale(struct adi_axi_adc_conv *conv, int index,
 196                               unsigned int *val, unsigned int *val2)
 197{
 198        const struct adi_axi_adc_chip_info *info = conv->chip_info;
 199        const struct iio_chan_spec *chan = &info->channels[0];
 200        unsigned int tmp;
 201
 202        tmp = (info->scale_table[index][0] * 1000000ULL) >>
 203                        chan->scan_type.realbits;
 204        *val = tmp / 1000000;
 205        *val2 = tmp % 1000000;
 206}
 207
 208#define AD9467_CHAN(_chan, _si, _bits, _sign)                           \
 209{                                                                       \
 210        .type = IIO_VOLTAGE,                                            \
 211        .indexed = 1,                                                   \
 212        .channel = _chan,                                               \
 213        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
 214                BIT(IIO_CHAN_INFO_SAMP_FREQ),                           \
 215        .scan_index = _si,                                              \
 216        .scan_type = {                                                  \
 217                .sign = _sign,                                          \
 218                .realbits = _bits,                                      \
 219                .storagebits = 16,                                      \
 220        },                                                              \
 221}
 222
 223static const struct iio_chan_spec ad9434_channels[] = {
 224        AD9467_CHAN(0, 0, 12, 'S'),
 225};
 226
 227static const struct iio_chan_spec ad9467_channels[] = {
 228        AD9467_CHAN(0, 0, 16, 'S'),
 229};
 230
 231static const struct ad9467_chip_info ad9467_chip_tbl[] = {
 232        [ID_AD9265] = {
 233                .axi_adc_info = {
 234                        .id = CHIPID_AD9265,
 235                        .max_rate = 125000000UL,
 236                        .scale_table = ad9265_scale_table,
 237                        .num_scales = ARRAY_SIZE(ad9265_scale_table),
 238                        .channels = ad9467_channels,
 239                        .num_channels = ARRAY_SIZE(ad9467_channels),
 240                },
 241                .default_output_mode = AD9265_DEF_OUTPUT_MODE,
 242                .vref_mask = AD9265_REG_VREF_MASK,
 243        },
 244        [ID_AD9434] = {
 245                .axi_adc_info = {
 246                        .id = CHIPID_AD9434,
 247                        .max_rate = 500000000UL,
 248                        .scale_table = ad9434_scale_table,
 249                        .num_scales = ARRAY_SIZE(ad9434_scale_table),
 250                        .channels = ad9434_channels,
 251                        .num_channels = ARRAY_SIZE(ad9434_channels),
 252                },
 253                .default_output_mode = AD9434_DEF_OUTPUT_MODE,
 254                .vref_mask = AD9434_REG_VREF_MASK,
 255        },
 256        [ID_AD9467] = {
 257                .axi_adc_info = {
 258                        .id = CHIPID_AD9467,
 259                        .max_rate = 250000000UL,
 260                        .scale_table = ad9467_scale_table,
 261                        .num_scales = ARRAY_SIZE(ad9467_scale_table),
 262                        .channels = ad9467_channels,
 263                        .num_channels = ARRAY_SIZE(ad9467_channels),
 264                },
 265                .default_output_mode = AD9467_DEF_OUTPUT_MODE,
 266                .vref_mask = AD9467_REG_VREF_MASK,
 267        },
 268};
 269
 270static int ad9467_get_scale(struct adi_axi_adc_conv *conv, int *val, int *val2)
 271{
 272        const struct adi_axi_adc_chip_info *info = conv->chip_info;
 273        const struct ad9467_chip_info *info1 = to_ad9467_chip_info(info);
 274        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 275        unsigned int i, vref_val;
 276
 277        vref_val = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF);
 278
 279        vref_val &= info1->vref_mask;
 280
 281        for (i = 0; i < info->num_scales; i++) {
 282                if (vref_val == info->scale_table[i][1])
 283                        break;
 284        }
 285
 286        if (i == info->num_scales)
 287                return -ERANGE;
 288
 289        __ad9467_get_scale(conv, i, val, val2);
 290
 291        return IIO_VAL_INT_PLUS_MICRO;
 292}
 293
 294static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
 295{
 296        const struct adi_axi_adc_chip_info *info = conv->chip_info;
 297        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 298        unsigned int scale_val[2];
 299        unsigned int i;
 300
 301        if (val != 0)
 302                return -EINVAL;
 303
 304        for (i = 0; i < info->num_scales; i++) {
 305                __ad9467_get_scale(conv, i, &scale_val[0], &scale_val[1]);
 306                if (scale_val[0] != val || scale_val[1] != val2)
 307                        continue;
 308
 309                ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
 310                                 info->scale_table[i][1]);
 311                ad9467_spi_write(st->spi, AN877_ADC_REG_TRANSFER,
 312                                 AN877_ADC_TRANSFER_SYNC);
 313                return 0;
 314        }
 315
 316        return -EINVAL;
 317}
 318
 319static int ad9467_read_raw(struct adi_axi_adc_conv *conv,
 320                           struct iio_chan_spec const *chan,
 321                           int *val, int *val2, long m)
 322{
 323        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 324
 325        switch (m) {
 326        case IIO_CHAN_INFO_SCALE:
 327                return ad9467_get_scale(conv, val, val2);
 328        case IIO_CHAN_INFO_SAMP_FREQ:
 329                *val = clk_get_rate(st->clk);
 330
 331                return IIO_VAL_INT;
 332        default:
 333                return -EINVAL;
 334        }
 335}
 336
 337static int ad9467_write_raw(struct adi_axi_adc_conv *conv,
 338                            struct iio_chan_spec const *chan,
 339                            int val, int val2, long mask)
 340{
 341        const struct adi_axi_adc_chip_info *info = conv->chip_info;
 342        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 343        long r_clk;
 344
 345        switch (mask) {
 346        case IIO_CHAN_INFO_SCALE:
 347                return ad9467_set_scale(conv, val, val2);
 348        case IIO_CHAN_INFO_SAMP_FREQ:
 349                r_clk = clk_round_rate(st->clk, val);
 350                if (r_clk < 0 || r_clk > info->max_rate) {
 351                        dev_warn(&st->spi->dev,
 352                                 "Error setting ADC sample rate %ld", r_clk);
 353                        return -EINVAL;
 354                }
 355
 356                return clk_set_rate(st->clk, r_clk);
 357        default:
 358                return -EINVAL;
 359        }
 360}
 361
 362static int ad9467_outputmode_set(struct spi_device *spi, unsigned int mode)
 363{
 364        int ret;
 365
 366        ret = ad9467_spi_write(spi, AN877_ADC_REG_OUTPUT_MODE, mode);
 367        if (ret < 0)
 368                return ret;
 369
 370        return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
 371                                AN877_ADC_TRANSFER_SYNC);
 372}
 373
 374static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
 375{
 376        struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
 377
 378        return ad9467_outputmode_set(st->spi, st->output_mode);
 379}
 380
 381static void ad9467_clk_disable(void *data)
 382{
 383        struct ad9467_state *st = data;
 384
 385        clk_disable_unprepare(st->clk);
 386}
 387
 388static int ad9467_probe(struct spi_device *spi)
 389{
 390        const struct ad9467_chip_info *info;
 391        struct adi_axi_adc_conv *conv;
 392        struct ad9467_state *st;
 393        unsigned int id;
 394        int ret;
 395
 396        info = of_device_get_match_data(&spi->dev);
 397        if (!info)
 398                return -ENODEV;
 399
 400        conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st));
 401        if (IS_ERR(conv))
 402                return PTR_ERR(conv);
 403
 404        st = adi_axi_adc_conv_priv(conv);
 405        st->spi = spi;
 406
 407        st->clk = devm_clk_get(&spi->dev, "adc-clk");
 408        if (IS_ERR(st->clk))
 409                return PTR_ERR(st->clk);
 410
 411        ret = clk_prepare_enable(st->clk);
 412        if (ret < 0)
 413                return ret;
 414
 415        ret = devm_add_action_or_reset(&spi->dev, ad9467_clk_disable, st);
 416        if (ret)
 417                return ret;
 418
 419        st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
 420                                                   GPIOD_OUT_LOW);
 421        if (IS_ERR(st->pwrdown_gpio))
 422                return PTR_ERR(st->pwrdown_gpio);
 423
 424        st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
 425                                                 GPIOD_OUT_LOW);
 426        if (IS_ERR(st->reset_gpio))
 427                return PTR_ERR(st->reset_gpio);
 428
 429        if (st->reset_gpio) {
 430                udelay(1);
 431                ret = gpiod_direction_output(st->reset_gpio, 1);
 432                if (ret)
 433                        return ret;
 434                mdelay(10);
 435        }
 436
 437        conv->chip_info = &info->axi_adc_info;
 438
 439        id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID);
 440        if (id != conv->chip_info->id) {
 441                dev_err(&spi->dev, "Mismatch CHIP_ID, got 0x%X, expected 0x%X\n",
 442                        id, conv->chip_info->id);
 443                return -ENODEV;
 444        }
 445
 446        conv->reg_access = ad9467_reg_access;
 447        conv->write_raw = ad9467_write_raw;
 448        conv->read_raw = ad9467_read_raw;
 449        conv->preenable_setup = ad9467_preenable_setup;
 450
 451        st->output_mode = info->default_output_mode |
 452                          AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT;
 453
 454        return 0;
 455}
 456
 457static const struct of_device_id ad9467_of_match[] = {
 458        { .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
 459        { .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
 460        { .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
 461        {}
 462};
 463MODULE_DEVICE_TABLE(of, ad9467_of_match);
 464
 465static struct spi_driver ad9467_driver = {
 466        .driver = {
 467                .name = "ad9467",
 468                .of_match_table = ad9467_of_match,
 469        },
 470        .probe = ad9467_probe,
 471};
 472module_spi_driver(ad9467_driver);
 473
 474MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 475MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver");
 476MODULE_LICENSE("GPL v2");
 477