linux/drivers/iio/adc/qcom-spmi-vadc.c
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   1/*
   2 * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 and
   6 * only version 2 as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 */
  13
  14#include <linux/bitops.h>
  15#include <linux/completion.h>
  16#include <linux/delay.h>
  17#include <linux/err.h>
  18#include <linux/iio/iio.h>
  19#include <linux/interrupt.h>
  20#include <linux/kernel.h>
  21#include <linux/math64.h>
  22#include <linux/module.h>
  23#include <linux/of.h>
  24#include <linux/platform_device.h>
  25#include <linux/regmap.h>
  26#include <linux/slab.h>
  27#include <linux/log2.h>
  28
  29#include <dt-bindings/iio/qcom,spmi-vadc.h>
  30
  31/* VADC register and bit definitions */
  32#define VADC_REVISION2                          0x1
  33#define VADC_REVISION2_SUPPORTED_VADC           1
  34
  35#define VADC_PERPH_TYPE                         0x4
  36#define VADC_PERPH_TYPE_ADC                     8
  37
  38#define VADC_PERPH_SUBTYPE                      0x5
  39#define VADC_PERPH_SUBTYPE_VADC                 1
  40
  41#define VADC_STATUS1                            0x8
  42#define VADC_STATUS1_OP_MODE                    4
  43#define VADC_STATUS1_REQ_STS                    BIT(1)
  44#define VADC_STATUS1_EOC                        BIT(0)
  45#define VADC_STATUS1_REQ_STS_EOC_MASK           0x3
  46
  47#define VADC_MODE_CTL                           0x40
  48#define VADC_OP_MODE_SHIFT                      3
  49#define VADC_OP_MODE_NORMAL                     0
  50#define VADC_AMUX_TRIM_EN                       BIT(1)
  51#define VADC_ADC_TRIM_EN                        BIT(0)
  52
  53#define VADC_EN_CTL1                            0x46
  54#define VADC_EN_CTL1_SET                        BIT(7)
  55
  56#define VADC_ADC_CH_SEL_CTL                     0x48
  57
  58#define VADC_ADC_DIG_PARAM                      0x50
  59#define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT        2
  60
  61#define VADC_HW_SETTLE_DELAY                    0x51
  62
  63#define VADC_CONV_REQ                           0x52
  64#define VADC_CONV_REQ_SET                       BIT(7)
  65
  66#define VADC_FAST_AVG_CTL                       0x5a
  67#define VADC_FAST_AVG_EN                        0x5b
  68#define VADC_FAST_AVG_EN_SET                    BIT(7)
  69
  70#define VADC_ACCESS                             0xd0
  71#define VADC_ACCESS_DATA                        0xa5
  72
  73#define VADC_PERH_RESET_CTL3                    0xda
  74#define VADC_FOLLOW_WARM_RB                     BIT(2)
  75
  76#define VADC_DATA                               0x60    /* 16 bits */
  77
  78#define VADC_CONV_TIME_MIN_US                   2000
  79#define VADC_CONV_TIME_MAX_US                   2100
  80
  81/* Min ADC code represents 0V */
  82#define VADC_MIN_ADC_CODE                       0x6000
  83/* Max ADC code represents full-scale range of 1.8V */
  84#define VADC_MAX_ADC_CODE                       0xa800
  85
  86#define VADC_ABSOLUTE_RANGE_UV                  625000
  87#define VADC_RATIOMETRIC_RANGE_UV               1800000
  88
  89#define VADC_DEF_PRESCALING                     0 /* 1:1 */
  90#define VADC_DEF_DECIMATION                     0 /* 512 */
  91#define VADC_DEF_HW_SETTLE_TIME                 0 /* 0 us */
  92#define VADC_DEF_AVG_SAMPLES                    0 /* 1 sample */
  93#define VADC_DEF_CALIB_TYPE                     VADC_CALIB_ABSOLUTE
  94
  95#define VADC_DECIMATION_MIN                     512
  96#define VADC_DECIMATION_MAX                     4096
  97
  98#define VADC_HW_SETTLE_DELAY_MAX                10000
  99#define VADC_AVG_SAMPLES_MAX                    512
 100
 101#define KELVINMIL_CELSIUSMIL                    273150
 102
 103#define VADC_CHAN_MIN                   VADC_USBIN
 104#define VADC_CHAN_MAX                   VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM
 105
 106/*
 107 * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
 108 * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
 109 * calibration.
 110 */
 111enum vadc_calibration {
 112        VADC_CALIB_ABSOLUTE = 0,
 113        VADC_CALIB_RATIOMETRIC
 114};
 115
 116/**
 117 * struct vadc_linear_graph - Represent ADC characteristics.
 118 * @dy: numerator slope to calculate the gain.
 119 * @dx: denominator slope to calculate the gain.
 120 * @gnd: A/D word of the ground reference used for the channel.
 121 *
 122 * Each ADC device has different offset and gain parameters which are
 123 * computed to calibrate the device.
 124 */
 125struct vadc_linear_graph {
 126        s32 dy;
 127        s32 dx;
 128        s32 gnd;
 129};
 130
 131/**
 132 * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
 133 * @num: the inverse numerator of the gain applied to the input channel.
 134 * @den: the inverse denominator of the gain applied to the input channel.
 135 */
 136struct vadc_prescale_ratio {
 137        u32 num;
 138        u32 den;
 139};
 140
 141/**
 142 * struct vadc_channel_prop - VADC channel property.
 143 * @channel: channel number, refer to the channel list.
 144 * @calibration: calibration type.
 145 * @decimation: sampling rate supported for the channel.
 146 * @prescale: channel scaling performed on the input signal.
 147 * @hw_settle_time: the time between AMUX being configured and the
 148 *      start of conversion.
 149 * @avg_samples: ability to provide single result from the ADC
 150 *      that is an average of multiple measurements.
 151 */
 152struct vadc_channel_prop {
 153        unsigned int channel;
 154        enum vadc_calibration calibration;
 155        unsigned int decimation;
 156        unsigned int prescale;
 157        unsigned int hw_settle_time;
 158        unsigned int avg_samples;
 159};
 160
 161/**
 162 * struct vadc_priv - VADC private structure.
 163 * @regmap: pointer to struct regmap.
 164 * @dev: pointer to struct device.
 165 * @base: base address for the ADC peripheral.
 166 * @nchannels: number of VADC channels.
 167 * @chan_props: array of VADC channel properties.
 168 * @iio_chans: array of IIO channels specification.
 169 * @are_ref_measured: are reference points measured.
 170 * @poll_eoc: use polling instead of interrupt.
 171 * @complete: VADC result notification after interrupt is received.
 172 * @graph: store parameters for calibration.
 173 * @lock: ADC lock for access to the peripheral.
 174 */
 175struct vadc_priv {
 176        struct regmap            *regmap;
 177        struct device            *dev;
 178        u16                      base;
 179        unsigned int             nchannels;
 180        struct vadc_channel_prop *chan_props;
 181        struct iio_chan_spec     *iio_chans;
 182        bool                     are_ref_measured;
 183        bool                     poll_eoc;
 184        struct completion        complete;
 185        struct vadc_linear_graph graph[2];
 186        struct mutex             lock;
 187};
 188
 189static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
 190        {.num =  1, .den =  1},
 191        {.num =  1, .den =  3},
 192        {.num =  1, .den =  4},
 193        {.num =  1, .den =  6},
 194        {.num =  1, .den = 20},
 195        {.num =  1, .den =  8},
 196        {.num = 10, .den = 81},
 197        {.num =  1, .den = 10}
 198};
 199
 200static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
 201{
 202        return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
 203}
 204
 205static int vadc_write(struct vadc_priv *vadc, u16 offset, u8 data)
 206{
 207        return regmap_write(vadc->regmap, vadc->base + offset, data);
 208}
 209
 210static int vadc_reset(struct vadc_priv *vadc)
 211{
 212        u8 data;
 213        int ret;
 214
 215        ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
 216        if (ret)
 217                return ret;
 218
 219        ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
 220        if (ret)
 221                return ret;
 222
 223        ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
 224        if (ret)
 225                return ret;
 226
 227        data |= VADC_FOLLOW_WARM_RB;
 228
 229        return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
 230}
 231
 232static int vadc_set_state(struct vadc_priv *vadc, bool state)
 233{
 234        return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
 235}
 236
 237static void vadc_show_status(struct vadc_priv *vadc)
 238{
 239        u8 mode, sta1, chan, dig, en, req;
 240        int ret;
 241
 242        ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
 243        if (ret)
 244                return;
 245
 246        ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
 247        if (ret)
 248                return;
 249
 250        ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
 251        if (ret)
 252                return;
 253
 254        ret = vadc_read(vadc, VADC_CONV_REQ, &req);
 255        if (ret)
 256                return;
 257
 258        ret = vadc_read(vadc, VADC_STATUS1, &sta1);
 259        if (ret)
 260                return;
 261
 262        ret = vadc_read(vadc, VADC_EN_CTL1, &en);
 263        if (ret)
 264                return;
 265
 266        dev_err(vadc->dev,
 267                "mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
 268                mode, en, chan, dig, req, sta1);
 269}
 270
 271static int vadc_configure(struct vadc_priv *vadc,
 272                          struct vadc_channel_prop *prop)
 273{
 274        u8 decimation, mode_ctrl;
 275        int ret;
 276
 277        /* Mode selection */
 278        mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
 279                     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
 280        ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
 281        if (ret)
 282                return ret;
 283
 284        /* Channel selection */
 285        ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
 286        if (ret)
 287                return ret;
 288
 289        /* Digital parameter setup */
 290        decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
 291        ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
 292        if (ret)
 293                return ret;
 294
 295        /* HW settle time delay */
 296        ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
 297        if (ret)
 298                return ret;
 299
 300        ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
 301        if (ret)
 302                return ret;
 303
 304        if (prop->avg_samples)
 305                ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
 306        else
 307                ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);
 308
 309        return ret;
 310}
 311
 312static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
 313{
 314        unsigned int count, retry;
 315        u8 sta1;
 316        int ret;
 317
 318        retry = interval_us / VADC_CONV_TIME_MIN_US;
 319
 320        for (count = 0; count < retry; count++) {
 321                ret = vadc_read(vadc, VADC_STATUS1, &sta1);
 322                if (ret)
 323                        return ret;
 324
 325                sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
 326                if (sta1 == VADC_STATUS1_EOC)
 327                        return 0;
 328
 329                usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
 330        }
 331
 332        vadc_show_status(vadc);
 333
 334        return -ETIMEDOUT;
 335}
 336
 337static int vadc_read_result(struct vadc_priv *vadc, u16 *data)
 338{
 339        int ret;
 340
 341        ret = regmap_bulk_read(vadc->regmap, vadc->base + VADC_DATA, data, 2);
 342        if (ret)
 343                return ret;
 344
 345        *data = clamp_t(u16, *data, VADC_MIN_ADC_CODE, VADC_MAX_ADC_CODE);
 346
 347        return 0;
 348}
 349
 350static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
 351                                                  unsigned int num)
 352{
 353        unsigned int i;
 354
 355        for (i = 0; i < vadc->nchannels; i++)
 356                if (vadc->chan_props[i].channel == num)
 357                        return &vadc->chan_props[i];
 358
 359        dev_dbg(vadc->dev, "no such channel %02x\n", num);
 360
 361        return NULL;
 362}
 363
 364static int vadc_do_conversion(struct vadc_priv *vadc,
 365                              struct vadc_channel_prop *prop, u16 *data)
 366{
 367        unsigned int timeout;
 368        int ret;
 369
 370        mutex_lock(&vadc->lock);
 371
 372        ret = vadc_configure(vadc, prop);
 373        if (ret)
 374                goto unlock;
 375
 376        if (!vadc->poll_eoc)
 377                reinit_completion(&vadc->complete);
 378
 379        ret = vadc_set_state(vadc, true);
 380        if (ret)
 381                goto unlock;
 382
 383        ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
 384        if (ret)
 385                goto err_disable;
 386
 387        timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
 388
 389        if (vadc->poll_eoc) {
 390                ret = vadc_poll_wait_eoc(vadc, timeout);
 391        } else {
 392                ret = wait_for_completion_timeout(&vadc->complete, timeout);
 393                if (!ret) {
 394                        ret = -ETIMEDOUT;
 395                        goto err_disable;
 396                }
 397
 398                /* Double check conversion status */
 399                ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US);
 400                if (ret)
 401                        goto err_disable;
 402        }
 403
 404        ret = vadc_read_result(vadc, data);
 405
 406err_disable:
 407        vadc_set_state(vadc, false);
 408        if (ret)
 409                dev_err(vadc->dev, "conversion failed\n");
 410unlock:
 411        mutex_unlock(&vadc->lock);
 412        return ret;
 413}
 414
 415static int vadc_measure_ref_points(struct vadc_priv *vadc)
 416{
 417        struct vadc_channel_prop *prop;
 418        u16 read_1, read_2;
 419        int ret;
 420
 421        vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
 422        vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
 423
 424        prop = vadc_get_channel(vadc, VADC_REF_1250MV);
 425        ret = vadc_do_conversion(vadc, prop, &read_1);
 426        if (ret)
 427                goto err;
 428
 429        /* Try with buffered 625mV channel first */
 430        prop = vadc_get_channel(vadc, VADC_SPARE1);
 431        if (!prop)
 432                prop = vadc_get_channel(vadc, VADC_REF_625MV);
 433
 434        ret = vadc_do_conversion(vadc, prop, &read_2);
 435        if (ret)
 436                goto err;
 437
 438        if (read_1 == read_2) {
 439                ret = -EINVAL;
 440                goto err;
 441        }
 442
 443        vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
 444        vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;
 445
 446        /* Ratiometric calibration */
 447        prop = vadc_get_channel(vadc, VADC_VDD_VADC);
 448        ret = vadc_do_conversion(vadc, prop, &read_1);
 449        if (ret)
 450                goto err;
 451
 452        prop = vadc_get_channel(vadc, VADC_GND_REF);
 453        ret = vadc_do_conversion(vadc, prop, &read_2);
 454        if (ret)
 455                goto err;
 456
 457        if (read_1 == read_2) {
 458                ret = -EINVAL;
 459                goto err;
 460        }
 461
 462        vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
 463        vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
 464err:
 465        if (ret)
 466                dev_err(vadc->dev, "measure reference points failed\n");
 467
 468        return ret;
 469}
 470
 471static s32 vadc_calibrate(struct vadc_priv *vadc,
 472                          const struct vadc_channel_prop *prop, u16 adc_code)
 473{
 474        const struct vadc_prescale_ratio *prescale;
 475        s64 voltage;
 476
 477        voltage = adc_code - vadc->graph[prop->calibration].gnd;
 478        voltage *= vadc->graph[prop->calibration].dx;
 479        voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
 480
 481        if (prop->calibration == VADC_CALIB_ABSOLUTE)
 482                voltage += vadc->graph[prop->calibration].dx;
 483
 484        if (voltage < 0)
 485                voltage = 0;
 486
 487        prescale = &vadc_prescale_ratios[prop->prescale];
 488
 489        voltage = voltage * prescale->den;
 490
 491        return div64_s64(voltage, prescale->num);
 492}
 493
 494static int vadc_decimation_from_dt(u32 value)
 495{
 496        if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
 497            value > VADC_DECIMATION_MAX)
 498                return -EINVAL;
 499
 500        return __ffs64(value / VADC_DECIMATION_MIN);
 501}
 502
 503static int vadc_prescaling_from_dt(u32 num, u32 den)
 504{
 505        unsigned int pre;
 506
 507        for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
 508                if (vadc_prescale_ratios[pre].num == num &&
 509                    vadc_prescale_ratios[pre].den == den)
 510                        break;
 511
 512        if (pre == ARRAY_SIZE(vadc_prescale_ratios))
 513                return -EINVAL;
 514
 515        return pre;
 516}
 517
 518static int vadc_hw_settle_time_from_dt(u32 value)
 519{
 520        if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
 521                return -EINVAL;
 522
 523        if (value <= 1000)
 524                value /= 100;
 525        else
 526                value = value / 2000 + 10;
 527
 528        return value;
 529}
 530
 531static int vadc_avg_samples_from_dt(u32 value)
 532{
 533        if (!is_power_of_2(value) || value > VADC_AVG_SAMPLES_MAX)
 534                return -EINVAL;
 535
 536        return __ffs64(value);
 537}
 538
 539static int vadc_read_raw(struct iio_dev *indio_dev,
 540                         struct iio_chan_spec const *chan, int *val, int *val2,
 541                         long mask)
 542{
 543        struct vadc_priv *vadc = iio_priv(indio_dev);
 544        struct vadc_channel_prop *prop;
 545        u16 adc_code;
 546        int ret;
 547
 548        switch (mask) {
 549        case IIO_CHAN_INFO_PROCESSED:
 550                prop = &vadc->chan_props[chan->address];
 551                ret = vadc_do_conversion(vadc, prop, &adc_code);
 552                if (ret)
 553                        break;
 554
 555                *val = vadc_calibrate(vadc, prop, adc_code);
 556
 557                /* 2mV/K, return milli Celsius */
 558                *val /= 2;
 559                *val -= KELVINMIL_CELSIUSMIL;
 560                return IIO_VAL_INT;
 561        case IIO_CHAN_INFO_RAW:
 562                prop = &vadc->chan_props[chan->address];
 563                ret = vadc_do_conversion(vadc, prop, &adc_code);
 564                if (ret)
 565                        break;
 566
 567                *val = vadc_calibrate(vadc, prop, adc_code);
 568                return IIO_VAL_INT;
 569        case IIO_CHAN_INFO_SCALE:
 570                *val = 0;
 571                *val2 = 1000;
 572                return IIO_VAL_INT_PLUS_MICRO;
 573        default:
 574                ret = -EINVAL;
 575                break;
 576        }
 577
 578        return ret;
 579}
 580
 581static int vadc_of_xlate(struct iio_dev *indio_dev,
 582                         const struct of_phandle_args *iiospec)
 583{
 584        struct vadc_priv *vadc = iio_priv(indio_dev);
 585        unsigned int i;
 586
 587        for (i = 0; i < vadc->nchannels; i++)
 588                if (vadc->iio_chans[i].channel == iiospec->args[0])
 589                        return i;
 590
 591        return -EINVAL;
 592}
 593
 594static const struct iio_info vadc_info = {
 595        .read_raw = vadc_read_raw,
 596        .of_xlate = vadc_of_xlate,
 597        .driver_module = THIS_MODULE,
 598};
 599
 600struct vadc_channels {
 601        const char *datasheet_name;
 602        unsigned int prescale_index;
 603        enum iio_chan_type type;
 604        long info_mask;
 605};
 606
 607#define VADC_CHAN(_dname, _type, _mask, _pre)                           \
 608        [VADC_##_dname] = {                                             \
 609                .datasheet_name = __stringify(_dname),                  \
 610                .prescale_index = _pre,                                 \
 611                .type = _type,                                          \
 612                .info_mask = _mask                                      \
 613        },                                                              \
 614
 615#define VADC_CHAN_TEMP(_dname, _pre)                                    \
 616        VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre) \
 617
 618#define VADC_CHAN_VOLT(_dname, _pre)                                    \
 619        VADC_CHAN(_dname, IIO_VOLTAGE,                                  \
 620                  BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),    \
 621                  _pre)                                                 \
 622
 623/*
 624 * The array represents all possible ADC channels found in the supported PMICs.
 625 * Every index in the array is equal to the channel number per datasheet. The
 626 * gaps in the array should be treated as reserved channels.
 627 */
 628static const struct vadc_channels vadc_chans[] = {
 629        VADC_CHAN_VOLT(USBIN, 4)
 630        VADC_CHAN_VOLT(DCIN, 4)
 631        VADC_CHAN_VOLT(VCHG_SNS, 3)
 632        VADC_CHAN_VOLT(SPARE1_03, 1)
 633        VADC_CHAN_VOLT(USB_ID_MV, 1)
 634        VADC_CHAN_VOLT(VCOIN, 1)
 635        VADC_CHAN_VOLT(VBAT_SNS, 1)
 636        VADC_CHAN_VOLT(VSYS, 1)
 637        VADC_CHAN_TEMP(DIE_TEMP, 0)
 638        VADC_CHAN_VOLT(REF_625MV, 0)
 639        VADC_CHAN_VOLT(REF_1250MV, 0)
 640        VADC_CHAN_VOLT(CHG_TEMP, 0)
 641        VADC_CHAN_VOLT(SPARE1, 0)
 642        VADC_CHAN_VOLT(SPARE2, 0)
 643        VADC_CHAN_VOLT(GND_REF, 0)
 644        VADC_CHAN_VOLT(VDD_VADC, 0)
 645
 646        VADC_CHAN_VOLT(P_MUX1_1_1, 0)
 647        VADC_CHAN_VOLT(P_MUX2_1_1, 0)
 648        VADC_CHAN_VOLT(P_MUX3_1_1, 0)
 649        VADC_CHAN_VOLT(P_MUX4_1_1, 0)
 650        VADC_CHAN_VOLT(P_MUX5_1_1, 0)
 651        VADC_CHAN_VOLT(P_MUX6_1_1, 0)
 652        VADC_CHAN_VOLT(P_MUX7_1_1, 0)
 653        VADC_CHAN_VOLT(P_MUX8_1_1, 0)
 654        VADC_CHAN_VOLT(P_MUX9_1_1, 0)
 655        VADC_CHAN_VOLT(P_MUX10_1_1, 0)
 656        VADC_CHAN_VOLT(P_MUX11_1_1, 0)
 657        VADC_CHAN_VOLT(P_MUX12_1_1, 0)
 658        VADC_CHAN_VOLT(P_MUX13_1_1, 0)
 659        VADC_CHAN_VOLT(P_MUX14_1_1, 0)
 660        VADC_CHAN_VOLT(P_MUX15_1_1, 0)
 661        VADC_CHAN_VOLT(P_MUX16_1_1, 0)
 662
 663        VADC_CHAN_VOLT(P_MUX1_1_3, 1)
 664        VADC_CHAN_VOLT(P_MUX2_1_3, 1)
 665        VADC_CHAN_VOLT(P_MUX3_1_3, 1)
 666        VADC_CHAN_VOLT(P_MUX4_1_3, 1)
 667        VADC_CHAN_VOLT(P_MUX5_1_3, 1)
 668        VADC_CHAN_VOLT(P_MUX6_1_3, 1)
 669        VADC_CHAN_VOLT(P_MUX7_1_3, 1)
 670        VADC_CHAN_VOLT(P_MUX8_1_3, 1)
 671        VADC_CHAN_VOLT(P_MUX9_1_3, 1)
 672        VADC_CHAN_VOLT(P_MUX10_1_3, 1)
 673        VADC_CHAN_VOLT(P_MUX11_1_3, 1)
 674        VADC_CHAN_VOLT(P_MUX12_1_3, 1)
 675        VADC_CHAN_VOLT(P_MUX13_1_3, 1)
 676        VADC_CHAN_VOLT(P_MUX14_1_3, 1)
 677        VADC_CHAN_VOLT(P_MUX15_1_3, 1)
 678        VADC_CHAN_VOLT(P_MUX16_1_3, 1)
 679
 680        VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
 681        VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
 682        VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
 683        VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
 684        VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
 685        VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
 686        VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
 687        VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
 688        VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
 689        VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
 690        VADC_CHAN_VOLT(AMUX_PU1, 0)
 691        VADC_CHAN_VOLT(AMUX_PU2, 0)
 692        VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
 693
 694        VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
 695        VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
 696        VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
 697        VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
 698        VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
 699        VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
 700        VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
 701        VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
 702        VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
 703        VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
 704        VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
 705
 706        VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
 707        VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
 708        VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
 709        VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
 710        VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
 711        VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
 712        VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
 713        VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
 714        VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
 715        VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
 716        VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
 717
 718        VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
 719        VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
 720        VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
 721        VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
 722        VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
 723        VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
 724        VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
 725        VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
 726        VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
 727        VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
 728        VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
 729};
 730
 731static int vadc_get_dt_channel_data(struct device *dev,
 732                                    struct vadc_channel_prop *prop,
 733                                    struct device_node *node)
 734{
 735        const char *name = node->name;
 736        u32 chan, value, varr[2];
 737        int ret;
 738
 739        ret = of_property_read_u32(node, "reg", &chan);
 740        if (ret) {
 741                dev_err(dev, "invalid channel number %s\n", name);
 742                return ret;
 743        }
 744
 745        if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
 746                dev_err(dev, "%s invalid channel number %d\n", name, chan);
 747                return -EINVAL;
 748        }
 749
 750        /* the channel has DT description */
 751        prop->channel = chan;
 752
 753        ret = of_property_read_u32(node, "qcom,decimation", &value);
 754        if (!ret) {
 755                ret = vadc_decimation_from_dt(value);
 756                if (ret < 0) {
 757                        dev_err(dev, "%02x invalid decimation %d\n",
 758                                chan, value);
 759                        return ret;
 760                }
 761                prop->decimation = ret;
 762        } else {
 763                prop->decimation = VADC_DEF_DECIMATION;
 764        }
 765
 766        ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
 767        if (!ret) {
 768                ret = vadc_prescaling_from_dt(varr[0], varr[1]);
 769                if (ret < 0) {
 770                        dev_err(dev, "%02x invalid pre-scaling <%d %d>\n",
 771                                chan, varr[0], varr[1]);
 772                        return ret;
 773                }
 774                prop->prescale = ret;
 775        } else {
 776                prop->prescale = vadc_chans[prop->channel].prescale_index;
 777        }
 778
 779        ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
 780        if (!ret) {
 781                ret = vadc_hw_settle_time_from_dt(value);
 782                if (ret < 0) {
 783                        dev_err(dev, "%02x invalid hw-settle-time %d us\n",
 784                                chan, value);
 785                        return ret;
 786                }
 787                prop->hw_settle_time = ret;
 788        } else {
 789                prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
 790        }
 791
 792        ret = of_property_read_u32(node, "qcom,avg-samples", &value);
 793        if (!ret) {
 794                ret = vadc_avg_samples_from_dt(value);
 795                if (ret < 0) {
 796                        dev_err(dev, "%02x invalid avg-samples %d\n",
 797                                chan, value);
 798                        return ret;
 799                }
 800                prop->avg_samples = ret;
 801        } else {
 802                prop->avg_samples = VADC_DEF_AVG_SAMPLES;
 803        }
 804
 805        if (of_property_read_bool(node, "qcom,ratiometric"))
 806                prop->calibration = VADC_CALIB_RATIOMETRIC;
 807        else
 808                prop->calibration = VADC_CALIB_ABSOLUTE;
 809
 810        dev_dbg(dev, "%02x name %s\n", chan, name);
 811
 812        return 0;
 813}
 814
 815static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
 816{
 817        const struct vadc_channels *vadc_chan;
 818        struct iio_chan_spec *iio_chan;
 819        struct vadc_channel_prop prop;
 820        struct device_node *child;
 821        unsigned int index = 0;
 822        int ret;
 823
 824        vadc->nchannels = of_get_available_child_count(node);
 825        if (!vadc->nchannels)
 826                return -EINVAL;
 827
 828        vadc->iio_chans = devm_kcalloc(vadc->dev, vadc->nchannels,
 829                                       sizeof(*vadc->iio_chans), GFP_KERNEL);
 830        if (!vadc->iio_chans)
 831                return -ENOMEM;
 832
 833        vadc->chan_props = devm_kcalloc(vadc->dev, vadc->nchannels,
 834                                        sizeof(*vadc->chan_props), GFP_KERNEL);
 835        if (!vadc->chan_props)
 836                return -ENOMEM;
 837
 838        iio_chan = vadc->iio_chans;
 839
 840        for_each_available_child_of_node(node, child) {
 841                ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
 842                if (ret) {
 843                        of_node_put(child);
 844                        return ret;
 845                }
 846
 847                vadc->chan_props[index] = prop;
 848
 849                vadc_chan = &vadc_chans[prop.channel];
 850
 851                iio_chan->channel = prop.channel;
 852                iio_chan->datasheet_name = vadc_chan->datasheet_name;
 853                iio_chan->info_mask_separate = vadc_chan->info_mask;
 854                iio_chan->type = vadc_chan->type;
 855                iio_chan->indexed = 1;
 856                iio_chan->address = index++;
 857
 858                iio_chan++;
 859        }
 860
 861        /* These channels are mandatory, they are used as reference points */
 862        if (!vadc_get_channel(vadc, VADC_REF_1250MV)) {
 863                dev_err(vadc->dev, "Please define 1.25V channel\n");
 864                return -ENODEV;
 865        }
 866
 867        if (!vadc_get_channel(vadc, VADC_REF_625MV)) {
 868                dev_err(vadc->dev, "Please define 0.625V channel\n");
 869                return -ENODEV;
 870        }
 871
 872        if (!vadc_get_channel(vadc, VADC_VDD_VADC)) {
 873                dev_err(vadc->dev, "Please define VDD channel\n");
 874                return -ENODEV;
 875        }
 876
 877        if (!vadc_get_channel(vadc, VADC_GND_REF)) {
 878                dev_err(vadc->dev, "Please define GND channel\n");
 879                return -ENODEV;
 880        }
 881
 882        return 0;
 883}
 884
 885static irqreturn_t vadc_isr(int irq, void *dev_id)
 886{
 887        struct vadc_priv *vadc = dev_id;
 888
 889        complete(&vadc->complete);
 890
 891        return IRQ_HANDLED;
 892}
 893
 894static int vadc_check_revision(struct vadc_priv *vadc)
 895{
 896        u8 val;
 897        int ret;
 898
 899        ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
 900        if (ret)
 901                return ret;
 902
 903        if (val < VADC_PERPH_TYPE_ADC) {
 904                dev_err(vadc->dev, "%d is not ADC\n", val);
 905                return -ENODEV;
 906        }
 907
 908        ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
 909        if (ret)
 910                return ret;
 911
 912        if (val < VADC_PERPH_SUBTYPE_VADC) {
 913                dev_err(vadc->dev, "%d is not VADC\n", val);
 914                return -ENODEV;
 915        }
 916
 917        ret = vadc_read(vadc, VADC_REVISION2, &val);
 918        if (ret)
 919                return ret;
 920
 921        if (val < VADC_REVISION2_SUPPORTED_VADC) {
 922                dev_err(vadc->dev, "revision %d not supported\n", val);
 923                return -ENODEV;
 924        }
 925
 926        return 0;
 927}
 928
 929static int vadc_probe(struct platform_device *pdev)
 930{
 931        struct device_node *node = pdev->dev.of_node;
 932        struct device *dev = &pdev->dev;
 933        struct iio_dev *indio_dev;
 934        struct vadc_priv *vadc;
 935        struct regmap *regmap;
 936        int ret, irq_eoc;
 937        u32 reg;
 938
 939        regmap = dev_get_regmap(dev->parent, NULL);
 940        if (!regmap)
 941                return -ENODEV;
 942
 943        ret = of_property_read_u32(node, "reg", &reg);
 944        if (ret < 0)
 945                return ret;
 946
 947        indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
 948        if (!indio_dev)
 949                return -ENOMEM;
 950
 951        vadc = iio_priv(indio_dev);
 952        vadc->regmap = regmap;
 953        vadc->dev = dev;
 954        vadc->base = reg;
 955        vadc->are_ref_measured = false;
 956        init_completion(&vadc->complete);
 957        mutex_init(&vadc->lock);
 958
 959        ret = vadc_check_revision(vadc);
 960        if (ret)
 961                return ret;
 962
 963        ret = vadc_get_dt_data(vadc, node);
 964        if (ret)
 965                return ret;
 966
 967        irq_eoc = platform_get_irq(pdev, 0);
 968        if (irq_eoc < 0) {
 969                if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
 970                        return irq_eoc;
 971                vadc->poll_eoc = true;
 972        } else {
 973                ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
 974                                       "spmi-vadc", vadc);
 975                if (ret)
 976                        return ret;
 977        }
 978
 979        ret = vadc_reset(vadc);
 980        if (ret) {
 981                dev_err(dev, "reset failed\n");
 982                return ret;
 983        }
 984
 985        ret = vadc_measure_ref_points(vadc);
 986        if (ret)
 987                return ret;
 988
 989        indio_dev->dev.parent = dev;
 990        indio_dev->dev.of_node = node;
 991        indio_dev->name = pdev->name;
 992        indio_dev->modes = INDIO_DIRECT_MODE;
 993        indio_dev->info = &vadc_info;
 994        indio_dev->channels = vadc->iio_chans;
 995        indio_dev->num_channels = vadc->nchannels;
 996
 997        return devm_iio_device_register(dev, indio_dev);
 998}
 999
1000static const struct of_device_id vadc_match_table[] = {
1001        { .compatible = "qcom,spmi-vadc" },
1002        { }
1003};
1004MODULE_DEVICE_TABLE(of, vadc_match_table);
1005
1006static struct platform_driver vadc_driver = {
1007        .driver = {
1008                   .name = "qcom-spmi-vadc",
1009                   .of_match_table = vadc_match_table,
1010        },
1011        .probe = vadc_probe,
1012};
1013module_platform_driver(vadc_driver);
1014
1015MODULE_ALIAS("platform:qcom-spmi-vadc");
1016MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
1017MODULE_LICENSE("GPL v2");
1018MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
1019MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");
1020