linux/drivers/iio/adc/cpcap-adc.c
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   1/*
   2 * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
   3 *
   4 * Rewritten for Linux IIO framework with some code based on
   5 * earlier driver found in the Motorola Linux kernel:
   6 *
   7 * Copyright (C) 2009-2010 Motorola, Inc.
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16 * GNU General Public License for more details.
  17 */
  18
  19#include <linux/delay.h>
  20#include <linux/device.h>
  21#include <linux/err.h>
  22#include <linux/init.h>
  23#include <linux/interrupt.h>
  24#include <linux/kernel.h>
  25#include <linux/module.h>
  26#include <linux/of.h>
  27#include <linux/of_platform.h>
  28#include <linux/platform_device.h>
  29#include <linux/regmap.h>
  30
  31#include <linux/iio/buffer.h>
  32#include <linux/iio/driver.h>
  33#include <linux/iio/iio.h>
  34#include <linux/iio/kfifo_buf.h>
  35#include <linux/mfd/motorola-cpcap.h>
  36
  37/* Register CPCAP_REG_ADCC1 bits */
  38#define CPCAP_BIT_ADEN_AUTO_CLR         BIT(15) /* Currently unused */
  39#define CPCAP_BIT_CAL_MODE              BIT(14) /* Set with BIT_RAND0 */
  40#define CPCAP_BIT_ADC_CLK_SEL1          BIT(13) /* Currently unused */
  41#define CPCAP_BIT_ADC_CLK_SEL0          BIT(12) /* Currently unused */
  42#define CPCAP_BIT_ATOX                  BIT(11)
  43#define CPCAP_BIT_ATO3                  BIT(10)
  44#define CPCAP_BIT_ATO2                  BIT(9)
  45#define CPCAP_BIT_ATO1                  BIT(8)
  46#define CPCAP_BIT_ATO0                  BIT(7)
  47#define CPCAP_BIT_ADA2                  BIT(6)
  48#define CPCAP_BIT_ADA1                  BIT(5)
  49#define CPCAP_BIT_ADA0                  BIT(4)
  50#define CPCAP_BIT_AD_SEL1               BIT(3)  /* Set for bank1 */
  51#define CPCAP_BIT_RAND1                 BIT(2)  /* Set for channel 16 & 17 */
  52#define CPCAP_BIT_RAND0                 BIT(1)  /* Set with CAL_MODE */
  53#define CPCAP_BIT_ADEN                  BIT(0)  /* Currently unused */
  54
  55#define CPCAP_REG_ADCC1_DEFAULTS        (CPCAP_BIT_ADEN_AUTO_CLR | \
  56                                         CPCAP_BIT_ADC_CLK_SEL0 |  \
  57                                         CPCAP_BIT_RAND1)
  58
  59/* Register CPCAP_REG_ADCC2 bits */
  60#define CPCAP_BIT_CAL_FACTOR_ENABLE     BIT(15) /* Currently unused */
  61#define CPCAP_BIT_BATDETB_EN            BIT(14) /* Currently unused */
  62#define CPCAP_BIT_ADTRIG_ONESHOT        BIT(13) /* Set for !TIMING_IMM */
  63#define CPCAP_BIT_ASC                   BIT(12) /* Set for TIMING_IMM */
  64#define CPCAP_BIT_ATOX_PS_FACTOR        BIT(11)
  65#define CPCAP_BIT_ADC_PS_FACTOR1        BIT(10)
  66#define CPCAP_BIT_ADC_PS_FACTOR0        BIT(9)
  67#define CPCAP_BIT_AD4_SELECT            BIT(8)  /* Currently unused */
  68#define CPCAP_BIT_ADC_BUSY              BIT(7)  /* Currently unused */
  69#define CPCAP_BIT_THERMBIAS_EN          BIT(6)  /* Bias for AD0_BATTDETB */
  70#define CPCAP_BIT_ADTRIG_DIS            BIT(5)  /* Disable interrupt */
  71#define CPCAP_BIT_LIADC                 BIT(4)  /* Currently unused */
  72#define CPCAP_BIT_TS_REFEN              BIT(3)  /* Currently unused */
  73#define CPCAP_BIT_TS_M2                 BIT(2)  /* Currently unused */
  74#define CPCAP_BIT_TS_M1                 BIT(1)  /* Currently unused */
  75#define CPCAP_BIT_TS_M0                 BIT(0)  /* Currently unused */
  76
  77#define CPCAP_REG_ADCC2_DEFAULTS        (CPCAP_BIT_AD4_SELECT | \
  78                                         CPCAP_BIT_ADTRIG_DIS | \
  79                                         CPCAP_BIT_LIADC | \
  80                                         CPCAP_BIT_TS_M2 | \
  81                                         CPCAP_BIT_TS_M1)
  82
  83#define CPCAP_MAX_TEMP_LVL              27
  84#define CPCAP_FOUR_POINT_TWO_ADC        801
  85#define ST_ADC_CAL_CHRGI_HIGH_THRESHOLD 530
  86#define ST_ADC_CAL_CHRGI_LOW_THRESHOLD  494
  87#define ST_ADC_CAL_BATTI_HIGH_THRESHOLD 530
  88#define ST_ADC_CAL_BATTI_LOW_THRESHOLD  494
  89#define ST_ADC_CALIBRATE_DIFF_THRESHOLD 3
  90
  91#define CPCAP_ADC_MAX_RETRIES           5       /* Calibration */
  92
  93/**
  94 * struct cpcap_adc_ato - timing settings for cpcap adc
  95 *
  96 * Unfortunately no cpcap documentation available, please document when
  97 * using these.
  98 */
  99struct cpcap_adc_ato {
 100        unsigned short ato_in;
 101        unsigned short atox_in;
 102        unsigned short adc_ps_factor_in;
 103        unsigned short atox_ps_factor_in;
 104        unsigned short ato_out;
 105        unsigned short atox_out;
 106        unsigned short adc_ps_factor_out;
 107        unsigned short atox_ps_factor_out;
 108};
 109
 110/**
 111 * struct cpcap-adc - cpcap adc device driver data
 112 * @reg: cpcap regmap
 113 * @dev: struct device
 114 * @vendor: cpcap vendor
 115 * @irq: interrupt
 116 * @lock: mutex
 117 * @ato: request timings
 118 * @wq_data_avail: work queue
 119 * @done: work done
 120 */
 121struct cpcap_adc {
 122        struct regmap *reg;
 123        struct device *dev;
 124        u16 vendor;
 125        int irq;
 126        struct mutex lock;      /* ADC register access lock */
 127        const struct cpcap_adc_ato *ato;
 128        wait_queue_head_t wq_data_avail;
 129        bool done;
 130};
 131
 132/**
 133 * enum cpcap_adc_channel - cpcap adc channels
 134 */
 135enum cpcap_adc_channel {
 136        /* Bank0 channels */
 137        CPCAP_ADC_AD0,          /* Battery temperature */
 138        CPCAP_ADC_BATTP,        /* Battery voltage */
 139        CPCAP_ADC_VBUS,         /* USB VBUS voltage */
 140        CPCAP_ADC_AD3,          /* Die temperature when charging */
 141        CPCAP_ADC_BPLUS_AD4,    /* Another battery or system voltage */
 142        CPCAP_ADC_CHG_ISENSE,   /* Calibrated charge current */
 143        CPCAP_ADC_BATTI,        /* Calibrated system current */
 144        CPCAP_ADC_USB_ID,       /* USB OTG ID, unused on droid 4? */
 145
 146        /* Bank1 channels */
 147        CPCAP_ADC_AD8,          /* Seems unused */
 148        CPCAP_ADC_AD9,          /* Seems unused */
 149        CPCAP_ADC_LICELL,       /* Maybe system voltage? Always 3V */
 150        CPCAP_ADC_HV_BATTP,     /* Another battery detection? */
 151        CPCAP_ADC_TSX1_AD12,    /* Seems unused, for touchscreen? */
 152        CPCAP_ADC_TSX2_AD13,    /* Seems unused, for touchscreen? */
 153        CPCAP_ADC_TSY1_AD14,    /* Seems unused, for touchscreen? */
 154        CPCAP_ADC_TSY2_AD15,    /* Seems unused, for touchscreen? */
 155
 156        /* Remuxed channels using bank0 entries */
 157        CPCAP_ADC_BATTP_PI16,   /* Alternative mux mode for BATTP */
 158        CPCAP_ADC_BATTI_PI17,   /* Alternative mux mode for BATTI */
 159
 160        CPCAP_ADC_CHANNEL_NUM,
 161};
 162
 163/**
 164 * enum cpcap_adc_timing - cpcap adc timing options
 165 *
 166 * CPCAP_ADC_TIMING_IMM seems to be immediate with no timings.
 167 * Please document when using.
 168 */
 169enum cpcap_adc_timing {
 170        CPCAP_ADC_TIMING_IMM,
 171        CPCAP_ADC_TIMING_IN,
 172        CPCAP_ADC_TIMING_OUT,
 173};
 174
 175/**
 176 * struct cpcap_adc_phasing_tbl - cpcap phasing table
 177 * @offset: offset in the phasing table
 178 * @multiplier: multiplier in the phasing table
 179 * @divider: divider in the phasing table
 180 * @min: minimum value
 181 * @max: maximum value
 182 */
 183struct cpcap_adc_phasing_tbl {
 184        short offset;
 185        unsigned short multiplier;
 186        unsigned short divider;
 187        short min;
 188        short max;
 189};
 190
 191/**
 192 * struct cpcap_adc_conversion_tbl - cpcap conversion table
 193 * @conv_type: conversion type
 194 * @align_offset: align offset
 195 * @conv_offset: conversion offset
 196 * @cal_offset: calibration offset
 197 * @multiplier: conversion multiplier
 198 * @divider: conversion divider
 199 */
 200struct cpcap_adc_conversion_tbl {
 201        enum iio_chan_info_enum conv_type;
 202        int align_offset;
 203        int conv_offset;
 204        int cal_offset;
 205        int multiplier;
 206        int divider;
 207};
 208
 209/**
 210 * struct cpcap_adc_request - cpcap adc request
 211 * @channel: request channel
 212 * @phase_tbl: channel phasing table
 213 * @conv_tbl: channel conversion table
 214 * @bank_index: channel index within the bank
 215 * @timing: timing settings
 216 * @result: result
 217 */
 218struct cpcap_adc_request {
 219        int channel;
 220        const struct cpcap_adc_phasing_tbl *phase_tbl;
 221        const struct cpcap_adc_conversion_tbl *conv_tbl;
 222        int bank_index;
 223        enum cpcap_adc_timing timing;
 224        int result;
 225};
 226
 227/* Phasing table for channels. Note that channels 16 & 17 use BATTP and BATTI */
 228static const struct cpcap_adc_phasing_tbl bank_phasing[] = {
 229        /* Bank0 */
 230        [CPCAP_ADC_AD0] =          {0, 0x80, 0x80,    0, 1023},
 231        [CPCAP_ADC_BATTP] =        {0, 0x80, 0x80,    0, 1023},
 232        [CPCAP_ADC_VBUS] =         {0, 0x80, 0x80,    0, 1023},
 233        [CPCAP_ADC_AD3] =          {0, 0x80, 0x80,    0, 1023},
 234        [CPCAP_ADC_BPLUS_AD4] =    {0, 0x80, 0x80,    0, 1023},
 235        [CPCAP_ADC_CHG_ISENSE] =   {0, 0x80, 0x80, -512,  511},
 236        [CPCAP_ADC_BATTI] =        {0, 0x80, 0x80, -512,  511},
 237        [CPCAP_ADC_USB_ID] =       {0, 0x80, 0x80,    0, 1023},
 238
 239        /* Bank1 */
 240        [CPCAP_ADC_AD8] =          {0, 0x80, 0x80,    0, 1023},
 241        [CPCAP_ADC_AD9] =          {0, 0x80, 0x80,    0, 1023},
 242        [CPCAP_ADC_LICELL] =       {0, 0x80, 0x80,    0, 1023},
 243        [CPCAP_ADC_HV_BATTP] =     {0, 0x80, 0x80,    0, 1023},
 244        [CPCAP_ADC_TSX1_AD12] =    {0, 0x80, 0x80,    0, 1023},
 245        [CPCAP_ADC_TSX2_AD13] =    {0, 0x80, 0x80,    0, 1023},
 246        [CPCAP_ADC_TSY1_AD14] =    {0, 0x80, 0x80,    0, 1023},
 247        [CPCAP_ADC_TSY2_AD15] =    {0, 0x80, 0x80,    0, 1023},
 248};
 249
 250/*
 251 * Conversion table for channels. Updated during init based on calibration.
 252 * Here too channels 16 & 17 use BATTP and BATTI.
 253 */
 254static struct cpcap_adc_conversion_tbl bank_conversion[] = {
 255        /* Bank0 */
 256        [CPCAP_ADC_AD0] = {
 257                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
 258        },
 259        [CPCAP_ADC_BATTP] = {
 260                IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
 261        },
 262        [CPCAP_ADC_VBUS] = {
 263                IIO_CHAN_INFO_PROCESSED,    0,    0, 0, 10000, 1023,
 264        },
 265        [CPCAP_ADC_AD3] = {
 266                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
 267                },
 268        [CPCAP_ADC_BPLUS_AD4] = {
 269                IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
 270        },
 271        [CPCAP_ADC_CHG_ISENSE] = {
 272                IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
 273        },
 274        [CPCAP_ADC_BATTI] = {
 275                IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
 276        },
 277        [CPCAP_ADC_USB_ID] = {
 278                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 279        },
 280
 281        /* Bank1 */
 282        [CPCAP_ADC_AD8] = {
 283                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 284        },
 285        [CPCAP_ADC_AD9] = {
 286                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 287        },
 288        [CPCAP_ADC_LICELL] = {
 289                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,  3400, 1023,
 290        },
 291        [CPCAP_ADC_HV_BATTP] = {
 292                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 293        },
 294        [CPCAP_ADC_TSX1_AD12] = {
 295                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 296        },
 297        [CPCAP_ADC_TSX2_AD13] = {
 298                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 299        },
 300        [CPCAP_ADC_TSY1_AD14] = {
 301                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 302        },
 303        [CPCAP_ADC_TSY2_AD15] = {
 304                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 305        },
 306};
 307
 308/*
 309 * Temperature lookup table of register values to milliCelcius.
 310 * REVISIT: Check the duplicate 0x3ff entry in a freezer
 311 */
 312static const int temp_map[CPCAP_MAX_TEMP_LVL][2] = {
 313        { 0x03ff, -40000 },
 314        { 0x03ff, -35000 },
 315        { 0x03ef, -30000 },
 316        { 0x03b2, -25000 },
 317        { 0x036c, -20000 },
 318        { 0x0320, -15000 },
 319        { 0x02d0, -10000 },
 320        { 0x027f, -5000 },
 321        { 0x022f, 0 },
 322        { 0x01e4, 5000 },
 323        { 0x019f, 10000 },
 324        { 0x0161, 15000 },
 325        { 0x012b, 20000 },
 326        { 0x00fc, 25000 },
 327        { 0x00d4, 30000 },
 328        { 0x00b2, 35000 },
 329        { 0x0095, 40000 },
 330        { 0x007d, 45000 },
 331        { 0x0069, 50000 },
 332        { 0x0059, 55000 },
 333        { 0x004b, 60000 },
 334        { 0x003f, 65000 },
 335        { 0x0036, 70000 },
 336        { 0x002e, 75000 },
 337        { 0x0027, 80000 },
 338        { 0x0022, 85000 },
 339        { 0x001d, 90000 },
 340};
 341
 342#define CPCAP_CHAN(_type, _index, _address, _datasheet_name) {  \
 343        .type = (_type), \
 344        .address = (_address), \
 345        .indexed = 1, \
 346        .channel = (_index), \
 347        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 348                              BIT(IIO_CHAN_INFO_PROCESSED), \
 349        .scan_index = (_index), \
 350        .scan_type = { \
 351                .sign = 'u', \
 352                .realbits = 10, \
 353                .storagebits = 16, \
 354                .endianness = IIO_CPU, \
 355        }, \
 356        .datasheet_name = (_datasheet_name), \
 357}
 358
 359/*
 360 * The datasheet names are from Motorola mapphone Linux kernel except
 361 * for the last two which might be uncalibrated charge voltage and
 362 * current.
 363 */
 364static const struct iio_chan_spec cpcap_adc_channels[] = {
 365        /* Bank0 */
 366        CPCAP_CHAN(IIO_TEMP,    0, CPCAP_REG_ADCD0,  "battdetb"),
 367        CPCAP_CHAN(IIO_VOLTAGE, 1, CPCAP_REG_ADCD1,  "battp"),
 368        CPCAP_CHAN(IIO_VOLTAGE, 2, CPCAP_REG_ADCD2,  "vbus"),
 369        CPCAP_CHAN(IIO_TEMP,    3, CPCAP_REG_ADCD3,  "ad3"),
 370        CPCAP_CHAN(IIO_VOLTAGE, 4, CPCAP_REG_ADCD4,  "ad4"),
 371        CPCAP_CHAN(IIO_CURRENT, 5, CPCAP_REG_ADCD5,  "chg_isense"),
 372        CPCAP_CHAN(IIO_CURRENT, 6, CPCAP_REG_ADCD6,  "batti"),
 373        CPCAP_CHAN(IIO_VOLTAGE, 7, CPCAP_REG_ADCD7,  "usb_id"),
 374
 375        /* Bank1 */
 376        CPCAP_CHAN(IIO_CURRENT, 8, CPCAP_REG_ADCD0,  "ad8"),
 377        CPCAP_CHAN(IIO_VOLTAGE, 9, CPCAP_REG_ADCD1,  "ad9"),
 378        CPCAP_CHAN(IIO_VOLTAGE, 10, CPCAP_REG_ADCD2, "licell"),
 379        CPCAP_CHAN(IIO_VOLTAGE, 11, CPCAP_REG_ADCD3, "hv_battp"),
 380        CPCAP_CHAN(IIO_VOLTAGE, 12, CPCAP_REG_ADCD4, "tsx1_ad12"),
 381        CPCAP_CHAN(IIO_VOLTAGE, 13, CPCAP_REG_ADCD5, "tsx2_ad13"),
 382        CPCAP_CHAN(IIO_VOLTAGE, 14, CPCAP_REG_ADCD6, "tsy1_ad14"),
 383        CPCAP_CHAN(IIO_VOLTAGE, 15, CPCAP_REG_ADCD7, "tsy2_ad15"),
 384
 385        /* There are two registers with multiplexed functionality */
 386        CPCAP_CHAN(IIO_VOLTAGE, 16, CPCAP_REG_ADCD0, "chg_vsense"),
 387        CPCAP_CHAN(IIO_CURRENT, 17, CPCAP_REG_ADCD1, "batti2"),
 388};
 389
 390static irqreturn_t cpcap_adc_irq_thread(int irq, void *data)
 391{
 392        struct iio_dev *indio_dev = data;
 393        struct cpcap_adc *ddata = iio_priv(indio_dev);
 394        int error;
 395
 396        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 397                                   CPCAP_BIT_ADTRIG_DIS,
 398                                   CPCAP_BIT_ADTRIG_DIS);
 399        if (error)
 400                return IRQ_NONE;
 401
 402        ddata->done = true;
 403        wake_up_interruptible(&ddata->wq_data_avail);
 404
 405        return IRQ_HANDLED;
 406}
 407
 408/* ADC calibration functions */
 409static void cpcap_adc_setup_calibrate(struct cpcap_adc *ddata,
 410                                      enum cpcap_adc_channel chan)
 411{
 412        unsigned int value = 0;
 413        unsigned long timeout = jiffies + msecs_to_jiffies(3000);
 414        int error;
 415
 416        if ((chan != CPCAP_ADC_CHG_ISENSE) &&
 417            (chan != CPCAP_ADC_BATTI))
 418                return;
 419
 420        value |= CPCAP_BIT_CAL_MODE | CPCAP_BIT_RAND0;
 421        value |= ((chan << 4) &
 422                  (CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 | CPCAP_BIT_ADA0));
 423
 424        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 425                                   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
 426                                   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
 427                                   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
 428                                   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
 429                                   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
 430                                   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
 431                                   value);
 432        if (error)
 433                return;
 434
 435        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 436                                   CPCAP_BIT_ATOX_PS_FACTOR |
 437                                   CPCAP_BIT_ADC_PS_FACTOR1 |
 438                                   CPCAP_BIT_ADC_PS_FACTOR0,
 439                                   0);
 440        if (error)
 441                return;
 442
 443        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 444                                   CPCAP_BIT_ADTRIG_DIS,
 445                                   CPCAP_BIT_ADTRIG_DIS);
 446        if (error)
 447                return;
 448
 449        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 450                                   CPCAP_BIT_ASC,
 451                                   CPCAP_BIT_ASC);
 452        if (error)
 453                return;
 454
 455        do {
 456                schedule_timeout_uninterruptible(1);
 457                error = regmap_read(ddata->reg, CPCAP_REG_ADCC2, &value);
 458                if (error)
 459                        return;
 460        } while ((value & CPCAP_BIT_ASC) && time_before(jiffies, timeout));
 461
 462        if (value & CPCAP_BIT_ASC)
 463                dev_err(ddata->dev,
 464                        "Timeout waiting for calibration to complete\n");
 465
 466        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 467                                   CPCAP_BIT_CAL_MODE, 0);
 468        if (error)
 469                return;
 470}
 471
 472static int cpcap_adc_calibrate_one(struct cpcap_adc *ddata,
 473                                   int channel,
 474                                   u16 calibration_register,
 475                                   int lower_threshold,
 476                                   int upper_threshold)
 477{
 478        unsigned int calibration_data[2];
 479        unsigned short cal_data_diff;
 480        int i, error;
 481
 482        for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
 483                calibration_data[0]  = 0;
 484                calibration_data[1]  = 0;
 485                cal_data_diff = 0;
 486                cpcap_adc_setup_calibrate(ddata, channel);
 487                error = regmap_read(ddata->reg, calibration_register,
 488                                    &calibration_data[0]);
 489                if (error)
 490                        return error;
 491                cpcap_adc_setup_calibrate(ddata, channel);
 492                error = regmap_read(ddata->reg, calibration_register,
 493                                    &calibration_data[1]);
 494                if (error)
 495                        return error;
 496
 497                if (calibration_data[0] > calibration_data[1])
 498                        cal_data_diff =
 499                                calibration_data[0] - calibration_data[1];
 500                else
 501                        cal_data_diff =
 502                                calibration_data[1] - calibration_data[0];
 503
 504                if (((calibration_data[1] >= lower_threshold) &&
 505                     (calibration_data[1] <= upper_threshold) &&
 506                     (cal_data_diff <= ST_ADC_CALIBRATE_DIFF_THRESHOLD)) ||
 507                    (ddata->vendor == CPCAP_VENDOR_TI)) {
 508                        bank_conversion[channel].cal_offset =
 509                                ((short)calibration_data[1] * -1) + 512;
 510                        dev_dbg(ddata->dev, "ch%i calibration complete: %i\n",
 511                                channel, bank_conversion[channel].cal_offset);
 512                        break;
 513                }
 514                usleep_range(5000, 10000);
 515        }
 516
 517        return 0;
 518}
 519
 520static int cpcap_adc_calibrate(struct cpcap_adc *ddata)
 521{
 522        int error;
 523
 524        error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_CHG_ISENSE,
 525                                        CPCAP_REG_ADCAL1,
 526                                        ST_ADC_CAL_CHRGI_LOW_THRESHOLD,
 527                                        ST_ADC_CAL_CHRGI_HIGH_THRESHOLD);
 528        if (error)
 529                return error;
 530
 531        error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_BATTI,
 532                                        CPCAP_REG_ADCAL2,
 533                                        ST_ADC_CAL_BATTI_LOW_THRESHOLD,
 534                                        ST_ADC_CAL_BATTI_HIGH_THRESHOLD);
 535        if (error)
 536                return error;
 537
 538        return 0;
 539}
 540
 541/* ADC setup, read and scale functions */
 542static void cpcap_adc_setup_bank(struct cpcap_adc *ddata,
 543                                 struct cpcap_adc_request *req)
 544{
 545        const struct cpcap_adc_ato *ato = ddata->ato;
 546        unsigned short value1 = 0;
 547        unsigned short value2 = 0;
 548        int error;
 549
 550        if (!ato)
 551                return;
 552
 553        switch (req->channel) {
 554        case CPCAP_ADC_AD0:
 555                value2 |= CPCAP_BIT_THERMBIAS_EN;
 556                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 557                                           CPCAP_BIT_THERMBIAS_EN,
 558                                           value2);
 559                if (error)
 560                        return;
 561                usleep_range(800, 1000);
 562                break;
 563        case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
 564                value1 |= CPCAP_BIT_AD_SEL1;
 565                break;
 566        case CPCAP_ADC_BATTP_PI16 ... CPCAP_ADC_BATTI_PI17:
 567                value1 |= CPCAP_BIT_RAND1;
 568        default:
 569                break;
 570        }
 571
 572        switch (req->timing) {
 573        case CPCAP_ADC_TIMING_IN:
 574                value1 |= ato->ato_in;
 575                value1 |= ato->atox_in;
 576                value2 |= ato->adc_ps_factor_in;
 577                value2 |= ato->atox_ps_factor_in;
 578                break;
 579        case CPCAP_ADC_TIMING_OUT:
 580                value1 |= ato->ato_out;
 581                value1 |= ato->atox_out;
 582                value2 |= ato->adc_ps_factor_out;
 583                value2 |= ato->atox_ps_factor_out;
 584                break;
 585
 586        case CPCAP_ADC_TIMING_IMM:
 587        default:
 588                break;
 589        }
 590
 591        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 592                                   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
 593                                   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
 594                                   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
 595                                   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
 596                                   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
 597                                   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
 598                                   value1);
 599        if (error)
 600                return;
 601
 602        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 603                                   CPCAP_BIT_ATOX_PS_FACTOR |
 604                                   CPCAP_BIT_ADC_PS_FACTOR1 |
 605                                   CPCAP_BIT_ADC_PS_FACTOR0 |
 606                                   CPCAP_BIT_THERMBIAS_EN,
 607                                   value2);
 608        if (error)
 609                return;
 610
 611        if (req->timing == CPCAP_ADC_TIMING_IMM) {
 612                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 613                                           CPCAP_BIT_ADTRIG_DIS,
 614                                           CPCAP_BIT_ADTRIG_DIS);
 615                if (error)
 616                        return;
 617
 618                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 619                                           CPCAP_BIT_ASC,
 620                                           CPCAP_BIT_ASC);
 621                if (error)
 622                        return;
 623        } else {
 624                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 625                                           CPCAP_BIT_ADTRIG_ONESHOT,
 626                                           CPCAP_BIT_ADTRIG_ONESHOT);
 627                if (error)
 628                        return;
 629
 630                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 631                                           CPCAP_BIT_ADTRIG_DIS, 0);
 632                if (error)
 633                        return;
 634        }
 635}
 636
 637static int cpcap_adc_start_bank(struct cpcap_adc *ddata,
 638                                struct cpcap_adc_request *req)
 639{
 640        int i, error;
 641
 642        req->timing = CPCAP_ADC_TIMING_IMM;
 643        ddata->done = false;
 644
 645        for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
 646                cpcap_adc_setup_bank(ddata, req);
 647                error = wait_event_interruptible_timeout(ddata->wq_data_avail,
 648                                                         ddata->done,
 649                                                         msecs_to_jiffies(50));
 650                if (error > 0)
 651                        return 0;
 652
 653                if (error == 0) {
 654                        error = -ETIMEDOUT;
 655                        continue;
 656                }
 657
 658                if (error < 0)
 659                        return error;
 660        }
 661
 662        return error;
 663}
 664
 665static int cpcap_adc_stop_bank(struct cpcap_adc *ddata)
 666{
 667        int error;
 668
 669        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 670                                   0xffff,
 671                                   CPCAP_REG_ADCC1_DEFAULTS);
 672        if (error)
 673                return error;
 674
 675        return regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 676                                  0xffff,
 677                                  CPCAP_REG_ADCC2_DEFAULTS);
 678}
 679
 680static void cpcap_adc_phase(struct cpcap_adc_request *req)
 681{
 682        const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
 683        const struct cpcap_adc_phasing_tbl *phase_tbl = req->phase_tbl;
 684        int index = req->channel;
 685
 686        /* Remuxed channels 16 and 17 use BATTP and BATTI entries */
 687        switch (req->channel) {
 688        case CPCAP_ADC_BATTP:
 689        case CPCAP_ADC_BATTP_PI16:
 690                index = req->bank_index;
 691                req->result -= phase_tbl[index].offset;
 692                req->result -= CPCAP_FOUR_POINT_TWO_ADC;
 693                req->result *= phase_tbl[index].multiplier;
 694                if (phase_tbl[index].divider == 0)
 695                        return;
 696                req->result /= phase_tbl[index].divider;
 697                req->result += CPCAP_FOUR_POINT_TWO_ADC;
 698                break;
 699        case CPCAP_ADC_BATTI_PI17:
 700                index = req->bank_index;
 701                /* fallthrough */
 702        default:
 703                req->result += conv_tbl[index].cal_offset;
 704                req->result += conv_tbl[index].align_offset;
 705                req->result *= phase_tbl[index].multiplier;
 706                if (phase_tbl[index].divider == 0)
 707                        return;
 708                req->result /= phase_tbl[index].divider;
 709                req->result += phase_tbl[index].offset;
 710                break;
 711        }
 712
 713        if (req->result < phase_tbl[index].min)
 714                req->result = phase_tbl[index].min;
 715        else if (req->result > phase_tbl[index].max)
 716                req->result = phase_tbl[index].max;
 717}
 718
 719/* Looks up temperatures in a table and calculates averages if needed */
 720static int cpcap_adc_table_to_millicelcius(unsigned short value)
 721{
 722        int i, result = 0, alpha;
 723
 724        if (value <= temp_map[CPCAP_MAX_TEMP_LVL - 1][0])
 725                return temp_map[CPCAP_MAX_TEMP_LVL - 1][1];
 726
 727        if (value >= temp_map[0][0])
 728                return temp_map[0][1];
 729
 730        for (i = 0; i < CPCAP_MAX_TEMP_LVL - 1; i++) {
 731                if ((value <= temp_map[i][0]) &&
 732                    (value >= temp_map[i + 1][0])) {
 733                        if (value == temp_map[i][0]) {
 734                                result = temp_map[i][1];
 735                        } else if (value == temp_map[i + 1][0]) {
 736                                result = temp_map[i + 1][1];
 737                        } else {
 738                                alpha = ((value - temp_map[i][0]) * 1000) /
 739                                        (temp_map[i + 1][0] - temp_map[i][0]);
 740
 741                                result = temp_map[i][1] +
 742                                        ((alpha * (temp_map[i + 1][1] -
 743                                                 temp_map[i][1])) / 1000);
 744                        }
 745                        break;
 746                }
 747        }
 748
 749        return result;
 750}
 751
 752static void cpcap_adc_convert(struct cpcap_adc_request *req)
 753{
 754        const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
 755        int index = req->channel;
 756
 757        /* Remuxed channels 16 and 17 use BATTP and BATTI entries */
 758        switch (req->channel) {
 759        case CPCAP_ADC_BATTP_PI16:
 760                index = CPCAP_ADC_BATTP;
 761                break;
 762        case CPCAP_ADC_BATTI_PI17:
 763                index = CPCAP_ADC_BATTI;
 764                break;
 765        default:
 766                break;
 767        }
 768
 769        /* No conversion for raw channels */
 770        if (conv_tbl[index].conv_type == IIO_CHAN_INFO_RAW)
 771                return;
 772
 773        /* Temperatures use a lookup table instead of conversion table */
 774        if ((req->channel == CPCAP_ADC_AD0) ||
 775            (req->channel == CPCAP_ADC_AD3)) {
 776                req->result =
 777                        cpcap_adc_table_to_millicelcius(req->result);
 778
 779                return;
 780        }
 781
 782        /* All processed channels use a conversion table */
 783        req->result *= conv_tbl[index].multiplier;
 784        if (conv_tbl[index].divider == 0)
 785                return;
 786        req->result /= conv_tbl[index].divider;
 787        req->result += conv_tbl[index].conv_offset;
 788}
 789
 790/*
 791 * REVISIT: Check if timed sampling can use multiple channels at the
 792 * same time. If not, replace channel_mask with just channel.
 793 */
 794static int cpcap_adc_read_bank_scaled(struct cpcap_adc *ddata,
 795                                      struct cpcap_adc_request *req)
 796{
 797        int calibration_data, error, addr;
 798
 799        if (ddata->vendor == CPCAP_VENDOR_TI) {
 800                error = regmap_read(ddata->reg, CPCAP_REG_ADCAL1,
 801                                    &calibration_data);
 802                if (error)
 803                        return error;
 804                bank_conversion[CPCAP_ADC_CHG_ISENSE].cal_offset =
 805                        ((short)calibration_data * -1) + 512;
 806
 807                error = regmap_read(ddata->reg, CPCAP_REG_ADCAL2,
 808                                    &calibration_data);
 809                if (error)
 810                        return error;
 811                bank_conversion[CPCAP_ADC_BATTI].cal_offset =
 812                        ((short)calibration_data * -1) + 512;
 813        }
 814
 815        addr = CPCAP_REG_ADCD0 + req->bank_index * 4;
 816
 817        error = regmap_read(ddata->reg, addr, &req->result);
 818        if (error)
 819                return error;
 820
 821        req->result &= 0x3ff;
 822        cpcap_adc_phase(req);
 823        cpcap_adc_convert(req);
 824
 825        return 0;
 826}
 827
 828static int cpcap_adc_init_request(struct cpcap_adc_request *req,
 829                                  int channel)
 830{
 831        req->channel = channel;
 832        req->phase_tbl = bank_phasing;
 833        req->conv_tbl = bank_conversion;
 834
 835        switch (channel) {
 836        case CPCAP_ADC_AD0 ... CPCAP_ADC_USB_ID:
 837                req->bank_index = channel;
 838                break;
 839        case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
 840                req->bank_index = channel - 8;
 841                break;
 842        case CPCAP_ADC_BATTP_PI16:
 843                req->bank_index = CPCAP_ADC_BATTP;
 844                break;
 845        case CPCAP_ADC_BATTI_PI17:
 846                req->bank_index = CPCAP_ADC_BATTI;
 847                break;
 848        default:
 849                return -EINVAL;
 850        }
 851
 852        return 0;
 853}
 854
 855static int cpcap_adc_read_st_die_temp(struct cpcap_adc *ddata,
 856                                      int addr, int *val)
 857{
 858        int error;
 859
 860        error = regmap_read(ddata->reg, addr, val);
 861        if (error)
 862                return error;
 863
 864        *val -= 282;
 865        *val *= 114;
 866        *val += 25000;
 867
 868        return 0;
 869}
 870
 871static int cpcap_adc_read(struct iio_dev *indio_dev,
 872                          struct iio_chan_spec const *chan,
 873                          int *val, int *val2, long mask)
 874{
 875        struct cpcap_adc *ddata = iio_priv(indio_dev);
 876        struct cpcap_adc_request req;
 877        int error;
 878
 879        error = cpcap_adc_init_request(&req, chan->channel);
 880        if (error)
 881                return error;
 882
 883        switch (mask) {
 884        case IIO_CHAN_INFO_RAW:
 885                mutex_lock(&ddata->lock);
 886                error = cpcap_adc_start_bank(ddata, &req);
 887                if (error)
 888                        goto err_unlock;
 889                error = regmap_read(ddata->reg, chan->address, val);
 890                if (error)
 891                        goto err_unlock;
 892                error = cpcap_adc_stop_bank(ddata);
 893                if (error)
 894                        goto err_unlock;
 895                mutex_unlock(&ddata->lock);
 896                break;
 897        case IIO_CHAN_INFO_PROCESSED:
 898                mutex_lock(&ddata->lock);
 899                error = cpcap_adc_start_bank(ddata, &req);
 900                if (error)
 901                        goto err_unlock;
 902                if ((ddata->vendor == CPCAP_VENDOR_ST) &&
 903                    (chan->channel == CPCAP_ADC_AD3)) {
 904                        error = cpcap_adc_read_st_die_temp(ddata,
 905                                                           chan->address,
 906                                                           &req.result);
 907                        if (error)
 908                                goto err_unlock;
 909                } else {
 910                        error = cpcap_adc_read_bank_scaled(ddata, &req);
 911                        if (error)
 912                                goto err_unlock;
 913                }
 914                error = cpcap_adc_stop_bank(ddata);
 915                if (error)
 916                        goto err_unlock;
 917                mutex_unlock(&ddata->lock);
 918                *val = req.result;
 919                break;
 920        default:
 921                return -EINVAL;
 922        }
 923
 924        return IIO_VAL_INT;
 925
 926err_unlock:
 927        mutex_unlock(&ddata->lock);
 928        dev_err(ddata->dev, "error reading ADC: %i\n", error);
 929
 930        return error;
 931}
 932
 933static const struct iio_info cpcap_adc_info = {
 934        .read_raw = &cpcap_adc_read,
 935};
 936
 937/*
 938 * Configuration for Motorola mapphone series such as droid 4.
 939 * Copied from the Motorola mapphone kernel tree.
 940 */
 941static const struct cpcap_adc_ato mapphone_adc = {
 942        .ato_in = 0x0480,
 943        .atox_in = 0,
 944        .adc_ps_factor_in = 0x0200,
 945        .atox_ps_factor_in = 0,
 946        .ato_out = 0,
 947        .atox_out = 0,
 948        .adc_ps_factor_out = 0,
 949        .atox_ps_factor_out = 0,
 950};
 951
 952static const struct of_device_id cpcap_adc_id_table[] = {
 953        {
 954                .compatible = "motorola,cpcap-adc",
 955        },
 956        {
 957                .compatible = "motorola,mapphone-cpcap-adc",
 958                .data = &mapphone_adc,
 959        },
 960        { /* sentinel */ },
 961};
 962MODULE_DEVICE_TABLE(of, cpcap_adc_id_table);
 963
 964static int cpcap_adc_probe(struct platform_device *pdev)
 965{
 966        const struct of_device_id *match;
 967        struct cpcap_adc *ddata;
 968        struct iio_dev *indio_dev;
 969        int error;
 970
 971        match = of_match_device(of_match_ptr(cpcap_adc_id_table),
 972                                &pdev->dev);
 973        if (!match)
 974                return -EINVAL;
 975
 976        if (!match->data) {
 977                dev_err(&pdev->dev, "no configuration data found\n");
 978
 979                return -ENODEV;
 980        }
 981
 982        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ddata));
 983        if (!indio_dev) {
 984                dev_err(&pdev->dev, "failed to allocate iio device\n");
 985
 986                return -ENOMEM;
 987        }
 988        ddata = iio_priv(indio_dev);
 989        ddata->ato = match->data;
 990        ddata->dev = &pdev->dev;
 991
 992        mutex_init(&ddata->lock);
 993        init_waitqueue_head(&ddata->wq_data_avail);
 994
 995        indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 996        indio_dev->dev.parent = &pdev->dev;
 997        indio_dev->dev.of_node = pdev->dev.of_node;
 998        indio_dev->channels = cpcap_adc_channels;
 999        indio_dev->num_channels = ARRAY_SIZE(cpcap_adc_channels);
1000        indio_dev->name = dev_name(&pdev->dev);
1001        indio_dev->info = &cpcap_adc_info;
1002
1003        ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
1004        if (!ddata->reg)
1005                return -ENODEV;
1006
1007        error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
1008        if (error)
1009                return error;
1010
1011        platform_set_drvdata(pdev, indio_dev);
1012
1013        ddata->irq = platform_get_irq_byname(pdev, "adcdone");
1014        if (ddata->irq < 0)
1015                return -ENODEV;
1016
1017        error = devm_request_threaded_irq(&pdev->dev, ddata->irq, NULL,
1018                                          cpcap_adc_irq_thread,
1019                                          IRQF_TRIGGER_NONE,
1020                                          "cpcap-adc", indio_dev);
1021        if (error) {
1022                dev_err(&pdev->dev, "could not get irq: %i\n",
1023                        error);
1024
1025                return error;
1026        }
1027
1028        error = cpcap_adc_calibrate(ddata);
1029        if (error)
1030                return error;
1031
1032        dev_info(&pdev->dev, "CPCAP ADC device probed\n");
1033
1034        return devm_iio_device_register(&pdev->dev, indio_dev);
1035}
1036
1037static struct platform_driver cpcap_adc_driver = {
1038        .driver = {
1039                .name = "cpcap_adc",
1040                .of_match_table = of_match_ptr(cpcap_adc_id_table),
1041        },
1042        .probe = cpcap_adc_probe,
1043};
1044
1045module_platform_driver(cpcap_adc_driver);
1046
1047MODULE_ALIAS("platform:cpcap_adc");
1048MODULE_DESCRIPTION("CPCAP ADC driver");
1049MODULE_AUTHOR("Tony Lindgren <tony@atomide.com");
1050MODULE_LICENSE("GPL v2");
1051