linux/drivers/iio/adc/cpcap-adc.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
   4 *
   5 * Rewritten for Linux IIO framework with some code based on
   6 * earlier driver found in the Motorola Linux kernel:
   7 *
   8 * Copyright (C) 2009-2010 Motorola, Inc.
   9 */
  10
  11#include <linux/delay.h>
  12#include <linux/device.h>
  13#include <linux/err.h>
  14#include <linux/init.h>
  15#include <linux/interrupt.h>
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/of.h>
  19#include <linux/of_platform.h>
  20#include <linux/platform_device.h>
  21#include <linux/regmap.h>
  22
  23#include <linux/iio/buffer.h>
  24#include <linux/iio/driver.h>
  25#include <linux/iio/iio.h>
  26#include <linux/iio/kfifo_buf.h>
  27#include <linux/mfd/motorola-cpcap.h>
  28
  29/* Register CPCAP_REG_ADCC1 bits */
  30#define CPCAP_BIT_ADEN_AUTO_CLR         BIT(15) /* Currently unused */
  31#define CPCAP_BIT_CAL_MODE              BIT(14) /* Set with BIT_RAND0 */
  32#define CPCAP_BIT_ADC_CLK_SEL1          BIT(13) /* Currently unused */
  33#define CPCAP_BIT_ADC_CLK_SEL0          BIT(12) /* Currently unused */
  34#define CPCAP_BIT_ATOX                  BIT(11)
  35#define CPCAP_BIT_ATO3                  BIT(10)
  36#define CPCAP_BIT_ATO2                  BIT(9)
  37#define CPCAP_BIT_ATO1                  BIT(8)
  38#define CPCAP_BIT_ATO0                  BIT(7)
  39#define CPCAP_BIT_ADA2                  BIT(6)
  40#define CPCAP_BIT_ADA1                  BIT(5)
  41#define CPCAP_BIT_ADA0                  BIT(4)
  42#define CPCAP_BIT_AD_SEL1               BIT(3)  /* Set for bank1 */
  43#define CPCAP_BIT_RAND1                 BIT(2)  /* Set for channel 16 & 17 */
  44#define CPCAP_BIT_RAND0                 BIT(1)  /* Set with CAL_MODE */
  45#define CPCAP_BIT_ADEN                  BIT(0)  /* Currently unused */
  46
  47#define CPCAP_REG_ADCC1_DEFAULTS        (CPCAP_BIT_ADEN_AUTO_CLR | \
  48                                         CPCAP_BIT_ADC_CLK_SEL0 |  \
  49                                         CPCAP_BIT_RAND1)
  50
  51/* Register CPCAP_REG_ADCC2 bits */
  52#define CPCAP_BIT_CAL_FACTOR_ENABLE     BIT(15) /* Currently unused */
  53#define CPCAP_BIT_BATDETB_EN            BIT(14) /* Currently unused */
  54#define CPCAP_BIT_ADTRIG_ONESHOT        BIT(13) /* Set for !TIMING_IMM */
  55#define CPCAP_BIT_ASC                   BIT(12) /* Set for TIMING_IMM */
  56#define CPCAP_BIT_ATOX_PS_FACTOR        BIT(11)
  57#define CPCAP_BIT_ADC_PS_FACTOR1        BIT(10)
  58#define CPCAP_BIT_ADC_PS_FACTOR0        BIT(9)
  59#define CPCAP_BIT_AD4_SELECT            BIT(8)  /* Currently unused */
  60#define CPCAP_BIT_ADC_BUSY              BIT(7)  /* Currently unused */
  61#define CPCAP_BIT_THERMBIAS_EN          BIT(6)  /* Bias for AD0_BATTDETB */
  62#define CPCAP_BIT_ADTRIG_DIS            BIT(5)  /* Disable interrupt */
  63#define CPCAP_BIT_LIADC                 BIT(4)  /* Currently unused */
  64#define CPCAP_BIT_TS_REFEN              BIT(3)  /* Currently unused */
  65#define CPCAP_BIT_TS_M2                 BIT(2)  /* Currently unused */
  66#define CPCAP_BIT_TS_M1                 BIT(1)  /* Currently unused */
  67#define CPCAP_BIT_TS_M0                 BIT(0)  /* Currently unused */
  68
  69#define CPCAP_REG_ADCC2_DEFAULTS        (CPCAP_BIT_AD4_SELECT | \
  70                                         CPCAP_BIT_ADTRIG_DIS | \
  71                                         CPCAP_BIT_LIADC | \
  72                                         CPCAP_BIT_TS_M2 | \
  73                                         CPCAP_BIT_TS_M1)
  74
  75#define CPCAP_MAX_TEMP_LVL              27
  76#define CPCAP_FOUR_POINT_TWO_ADC        801
  77#define ST_ADC_CAL_CHRGI_HIGH_THRESHOLD 530
  78#define ST_ADC_CAL_CHRGI_LOW_THRESHOLD  494
  79#define ST_ADC_CAL_BATTI_HIGH_THRESHOLD 530
  80#define ST_ADC_CAL_BATTI_LOW_THRESHOLD  494
  81#define ST_ADC_CALIBRATE_DIFF_THRESHOLD 3
  82
  83#define CPCAP_ADC_MAX_RETRIES           5       /* Calibration */
  84
  85/**
  86 * struct cpcap_adc_ato - timing settings for cpcap adc
  87 *
  88 * Unfortunately no cpcap documentation available, please document when
  89 * using these.
  90 */
  91struct cpcap_adc_ato {
  92        unsigned short ato_in;
  93        unsigned short atox_in;
  94        unsigned short adc_ps_factor_in;
  95        unsigned short atox_ps_factor_in;
  96        unsigned short ato_out;
  97        unsigned short atox_out;
  98        unsigned short adc_ps_factor_out;
  99        unsigned short atox_ps_factor_out;
 100};
 101
 102/**
 103 * struct cpcap-adc - cpcap adc device driver data
 104 * @reg: cpcap regmap
 105 * @dev: struct device
 106 * @vendor: cpcap vendor
 107 * @irq: interrupt
 108 * @lock: mutex
 109 * @ato: request timings
 110 * @wq_data_avail: work queue
 111 * @done: work done
 112 */
 113struct cpcap_adc {
 114        struct regmap *reg;
 115        struct device *dev;
 116        u16 vendor;
 117        int irq;
 118        struct mutex lock;      /* ADC register access lock */
 119        const struct cpcap_adc_ato *ato;
 120        wait_queue_head_t wq_data_avail;
 121        bool done;
 122};
 123
 124/**
 125 * enum cpcap_adc_channel - cpcap adc channels
 126 */
 127enum cpcap_adc_channel {
 128        /* Bank0 channels */
 129        CPCAP_ADC_AD0,          /* Battery temperature */
 130        CPCAP_ADC_BATTP,        /* Battery voltage */
 131        CPCAP_ADC_VBUS,         /* USB VBUS voltage */
 132        CPCAP_ADC_AD3,          /* Die temperature when charging */
 133        CPCAP_ADC_BPLUS_AD4,    /* Another battery or system voltage */
 134        CPCAP_ADC_CHG_ISENSE,   /* Calibrated charge current */
 135        CPCAP_ADC_BATTI,        /* Calibrated system current */
 136        CPCAP_ADC_USB_ID,       /* USB OTG ID, unused on droid 4? */
 137
 138        /* Bank1 channels */
 139        CPCAP_ADC_AD8,          /* Seems unused */
 140        CPCAP_ADC_AD9,          /* Seems unused */
 141        CPCAP_ADC_LICELL,       /* Maybe system voltage? Always 3V */
 142        CPCAP_ADC_HV_BATTP,     /* Another battery detection? */
 143        CPCAP_ADC_TSX1_AD12,    /* Seems unused, for touchscreen? */
 144        CPCAP_ADC_TSX2_AD13,    /* Seems unused, for touchscreen? */
 145        CPCAP_ADC_TSY1_AD14,    /* Seems unused, for touchscreen? */
 146        CPCAP_ADC_TSY2_AD15,    /* Seems unused, for touchscreen? */
 147
 148        /* Remuxed channels using bank0 entries */
 149        CPCAP_ADC_BATTP_PI16,   /* Alternative mux mode for BATTP */
 150        CPCAP_ADC_BATTI_PI17,   /* Alternative mux mode for BATTI */
 151
 152        CPCAP_ADC_CHANNEL_NUM,
 153};
 154
 155/**
 156 * enum cpcap_adc_timing - cpcap adc timing options
 157 *
 158 * CPCAP_ADC_TIMING_IMM seems to be immediate with no timings.
 159 * Please document when using.
 160 */
 161enum cpcap_adc_timing {
 162        CPCAP_ADC_TIMING_IMM,
 163        CPCAP_ADC_TIMING_IN,
 164        CPCAP_ADC_TIMING_OUT,
 165};
 166
 167/**
 168 * struct cpcap_adc_phasing_tbl - cpcap phasing table
 169 * @offset: offset in the phasing table
 170 * @multiplier: multiplier in the phasing table
 171 * @divider: divider in the phasing table
 172 * @min: minimum value
 173 * @max: maximum value
 174 */
 175struct cpcap_adc_phasing_tbl {
 176        short offset;
 177        unsigned short multiplier;
 178        unsigned short divider;
 179        short min;
 180        short max;
 181};
 182
 183/**
 184 * struct cpcap_adc_conversion_tbl - cpcap conversion table
 185 * @conv_type: conversion type
 186 * @align_offset: align offset
 187 * @conv_offset: conversion offset
 188 * @cal_offset: calibration offset
 189 * @multiplier: conversion multiplier
 190 * @divider: conversion divider
 191 */
 192struct cpcap_adc_conversion_tbl {
 193        enum iio_chan_info_enum conv_type;
 194        int align_offset;
 195        int conv_offset;
 196        int cal_offset;
 197        int multiplier;
 198        int divider;
 199};
 200
 201/**
 202 * struct cpcap_adc_request - cpcap adc request
 203 * @channel: request channel
 204 * @phase_tbl: channel phasing table
 205 * @conv_tbl: channel conversion table
 206 * @bank_index: channel index within the bank
 207 * @timing: timing settings
 208 * @result: result
 209 */
 210struct cpcap_adc_request {
 211        int channel;
 212        const struct cpcap_adc_phasing_tbl *phase_tbl;
 213        const struct cpcap_adc_conversion_tbl *conv_tbl;
 214        int bank_index;
 215        enum cpcap_adc_timing timing;
 216        int result;
 217};
 218
 219/* Phasing table for channels. Note that channels 16 & 17 use BATTP and BATTI */
 220static const struct cpcap_adc_phasing_tbl bank_phasing[] = {
 221        /* Bank0 */
 222        [CPCAP_ADC_AD0] =          {0, 0x80, 0x80,    0, 1023},
 223        [CPCAP_ADC_BATTP] =        {0, 0x80, 0x80,    0, 1023},
 224        [CPCAP_ADC_VBUS] =         {0, 0x80, 0x80,    0, 1023},
 225        [CPCAP_ADC_AD3] =          {0, 0x80, 0x80,    0, 1023},
 226        [CPCAP_ADC_BPLUS_AD4] =    {0, 0x80, 0x80,    0, 1023},
 227        [CPCAP_ADC_CHG_ISENSE] =   {0, 0x80, 0x80, -512,  511},
 228        [CPCAP_ADC_BATTI] =        {0, 0x80, 0x80, -512,  511},
 229        [CPCAP_ADC_USB_ID] =       {0, 0x80, 0x80,    0, 1023},
 230
 231        /* Bank1 */
 232        [CPCAP_ADC_AD8] =          {0, 0x80, 0x80,    0, 1023},
 233        [CPCAP_ADC_AD9] =          {0, 0x80, 0x80,    0, 1023},
 234        [CPCAP_ADC_LICELL] =       {0, 0x80, 0x80,    0, 1023},
 235        [CPCAP_ADC_HV_BATTP] =     {0, 0x80, 0x80,    0, 1023},
 236        [CPCAP_ADC_TSX1_AD12] =    {0, 0x80, 0x80,    0, 1023},
 237        [CPCAP_ADC_TSX2_AD13] =    {0, 0x80, 0x80,    0, 1023},
 238        [CPCAP_ADC_TSY1_AD14] =    {0, 0x80, 0x80,    0, 1023},
 239        [CPCAP_ADC_TSY2_AD15] =    {0, 0x80, 0x80,    0, 1023},
 240};
 241
 242/*
 243 * Conversion table for channels. Updated during init based on calibration.
 244 * Here too channels 16 & 17 use BATTP and BATTI.
 245 */
 246static struct cpcap_adc_conversion_tbl bank_conversion[] = {
 247        /* Bank0 */
 248        [CPCAP_ADC_AD0] = {
 249                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
 250        },
 251        [CPCAP_ADC_BATTP] = {
 252                IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
 253        },
 254        [CPCAP_ADC_VBUS] = {
 255                IIO_CHAN_INFO_PROCESSED,    0,    0, 0, 10000, 1023,
 256        },
 257        [CPCAP_ADC_AD3] = {
 258                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
 259                },
 260        [CPCAP_ADC_BPLUS_AD4] = {
 261                IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
 262        },
 263        [CPCAP_ADC_CHG_ISENSE] = {
 264                IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
 265        },
 266        [CPCAP_ADC_BATTI] = {
 267                IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
 268        },
 269        [CPCAP_ADC_USB_ID] = {
 270                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 271        },
 272
 273        /* Bank1 */
 274        [CPCAP_ADC_AD8] = {
 275                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 276        },
 277        [CPCAP_ADC_AD9] = {
 278                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 279        },
 280        [CPCAP_ADC_LICELL] = {
 281                IIO_CHAN_INFO_PROCESSED,    0,    0, 0,  3400, 1023,
 282        },
 283        [CPCAP_ADC_HV_BATTP] = {
 284                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 285        },
 286        [CPCAP_ADC_TSX1_AD12] = {
 287                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 288        },
 289        [CPCAP_ADC_TSX2_AD13] = {
 290                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 291        },
 292        [CPCAP_ADC_TSY1_AD14] = {
 293                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 294        },
 295        [CPCAP_ADC_TSY2_AD15] = {
 296                IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
 297        },
 298};
 299
 300/*
 301 * Temperature lookup table of register values to milliCelcius.
 302 * REVISIT: Check the duplicate 0x3ff entry in a freezer
 303 */
 304static const int temp_map[CPCAP_MAX_TEMP_LVL][2] = {
 305        { 0x03ff, -40000 },
 306        { 0x03ff, -35000 },
 307        { 0x03ef, -30000 },
 308        { 0x03b2, -25000 },
 309        { 0x036c, -20000 },
 310        { 0x0320, -15000 },
 311        { 0x02d0, -10000 },
 312        { 0x027f, -5000 },
 313        { 0x022f, 0 },
 314        { 0x01e4, 5000 },
 315        { 0x019f, 10000 },
 316        { 0x0161, 15000 },
 317        { 0x012b, 20000 },
 318        { 0x00fc, 25000 },
 319        { 0x00d4, 30000 },
 320        { 0x00b2, 35000 },
 321        { 0x0095, 40000 },
 322        { 0x007d, 45000 },
 323        { 0x0069, 50000 },
 324        { 0x0059, 55000 },
 325        { 0x004b, 60000 },
 326        { 0x003f, 65000 },
 327        { 0x0036, 70000 },
 328        { 0x002e, 75000 },
 329        { 0x0027, 80000 },
 330        { 0x0022, 85000 },
 331        { 0x001d, 90000 },
 332};
 333
 334#define CPCAP_CHAN(_type, _index, _address, _datasheet_name) {  \
 335        .type = (_type), \
 336        .address = (_address), \
 337        .indexed = 1, \
 338        .channel = (_index), \
 339        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 340                              BIT(IIO_CHAN_INFO_PROCESSED), \
 341        .scan_index = (_index), \
 342        .scan_type = { \
 343                .sign = 'u', \
 344                .realbits = 10, \
 345                .storagebits = 16, \
 346                .endianness = IIO_CPU, \
 347        }, \
 348        .datasheet_name = (_datasheet_name), \
 349}
 350
 351/*
 352 * The datasheet names are from Motorola mapphone Linux kernel except
 353 * for the last two which might be uncalibrated charge voltage and
 354 * current.
 355 */
 356static const struct iio_chan_spec cpcap_adc_channels[] = {
 357        /* Bank0 */
 358        CPCAP_CHAN(IIO_TEMP,    0, CPCAP_REG_ADCD0,  "battdetb"),
 359        CPCAP_CHAN(IIO_VOLTAGE, 1, CPCAP_REG_ADCD1,  "battp"),
 360        CPCAP_CHAN(IIO_VOLTAGE, 2, CPCAP_REG_ADCD2,  "vbus"),
 361        CPCAP_CHAN(IIO_TEMP,    3, CPCAP_REG_ADCD3,  "ad3"),
 362        CPCAP_CHAN(IIO_VOLTAGE, 4, CPCAP_REG_ADCD4,  "ad4"),
 363        CPCAP_CHAN(IIO_CURRENT, 5, CPCAP_REG_ADCD5,  "chg_isense"),
 364        CPCAP_CHAN(IIO_CURRENT, 6, CPCAP_REG_ADCD6,  "batti"),
 365        CPCAP_CHAN(IIO_VOLTAGE, 7, CPCAP_REG_ADCD7,  "usb_id"),
 366
 367        /* Bank1 */
 368        CPCAP_CHAN(IIO_CURRENT, 8, CPCAP_REG_ADCD0,  "ad8"),
 369        CPCAP_CHAN(IIO_VOLTAGE, 9, CPCAP_REG_ADCD1,  "ad9"),
 370        CPCAP_CHAN(IIO_VOLTAGE, 10, CPCAP_REG_ADCD2, "licell"),
 371        CPCAP_CHAN(IIO_VOLTAGE, 11, CPCAP_REG_ADCD3, "hv_battp"),
 372        CPCAP_CHAN(IIO_VOLTAGE, 12, CPCAP_REG_ADCD4, "tsx1_ad12"),
 373        CPCAP_CHAN(IIO_VOLTAGE, 13, CPCAP_REG_ADCD5, "tsx2_ad13"),
 374        CPCAP_CHAN(IIO_VOLTAGE, 14, CPCAP_REG_ADCD6, "tsy1_ad14"),
 375        CPCAP_CHAN(IIO_VOLTAGE, 15, CPCAP_REG_ADCD7, "tsy2_ad15"),
 376
 377        /* There are two registers with multiplexed functionality */
 378        CPCAP_CHAN(IIO_VOLTAGE, 16, CPCAP_REG_ADCD0, "chg_vsense"),
 379        CPCAP_CHAN(IIO_CURRENT, 17, CPCAP_REG_ADCD1, "batti2"),
 380};
 381
 382static irqreturn_t cpcap_adc_irq_thread(int irq, void *data)
 383{
 384        struct iio_dev *indio_dev = data;
 385        struct cpcap_adc *ddata = iio_priv(indio_dev);
 386        int error;
 387
 388        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 389                                   CPCAP_BIT_ADTRIG_DIS,
 390                                   CPCAP_BIT_ADTRIG_DIS);
 391        if (error)
 392                return IRQ_NONE;
 393
 394        ddata->done = true;
 395        wake_up_interruptible(&ddata->wq_data_avail);
 396
 397        return IRQ_HANDLED;
 398}
 399
 400/* ADC calibration functions */
 401static void cpcap_adc_setup_calibrate(struct cpcap_adc *ddata,
 402                                      enum cpcap_adc_channel chan)
 403{
 404        unsigned int value = 0;
 405        unsigned long timeout = jiffies + msecs_to_jiffies(3000);
 406        int error;
 407
 408        if ((chan != CPCAP_ADC_CHG_ISENSE) &&
 409            (chan != CPCAP_ADC_BATTI))
 410                return;
 411
 412        value |= CPCAP_BIT_CAL_MODE | CPCAP_BIT_RAND0;
 413        value |= ((chan << 4) &
 414                  (CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 | CPCAP_BIT_ADA0));
 415
 416        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 417                                   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
 418                                   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
 419                                   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
 420                                   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
 421                                   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
 422                                   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
 423                                   value);
 424        if (error)
 425                return;
 426
 427        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 428                                   CPCAP_BIT_ATOX_PS_FACTOR |
 429                                   CPCAP_BIT_ADC_PS_FACTOR1 |
 430                                   CPCAP_BIT_ADC_PS_FACTOR0,
 431                                   0);
 432        if (error)
 433                return;
 434
 435        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 436                                   CPCAP_BIT_ADTRIG_DIS,
 437                                   CPCAP_BIT_ADTRIG_DIS);
 438        if (error)
 439                return;
 440
 441        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 442                                   CPCAP_BIT_ASC,
 443                                   CPCAP_BIT_ASC);
 444        if (error)
 445                return;
 446
 447        do {
 448                schedule_timeout_uninterruptible(1);
 449                error = regmap_read(ddata->reg, CPCAP_REG_ADCC2, &value);
 450                if (error)
 451                        return;
 452        } while ((value & CPCAP_BIT_ASC) && time_before(jiffies, timeout));
 453
 454        if (value & CPCAP_BIT_ASC)
 455                dev_err(ddata->dev,
 456                        "Timeout waiting for calibration to complete\n");
 457
 458        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 459                                   CPCAP_BIT_CAL_MODE, 0);
 460        if (error)
 461                return;
 462}
 463
 464static int cpcap_adc_calibrate_one(struct cpcap_adc *ddata,
 465                                   int channel,
 466                                   u16 calibration_register,
 467                                   int lower_threshold,
 468                                   int upper_threshold)
 469{
 470        unsigned int calibration_data[2];
 471        unsigned short cal_data_diff;
 472        int i, error;
 473
 474        for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
 475                calibration_data[0]  = 0;
 476                calibration_data[1]  = 0;
 477                cal_data_diff = 0;
 478                cpcap_adc_setup_calibrate(ddata, channel);
 479                error = regmap_read(ddata->reg, calibration_register,
 480                                    &calibration_data[0]);
 481                if (error)
 482                        return error;
 483                cpcap_adc_setup_calibrate(ddata, channel);
 484                error = regmap_read(ddata->reg, calibration_register,
 485                                    &calibration_data[1]);
 486                if (error)
 487                        return error;
 488
 489                if (calibration_data[0] > calibration_data[1])
 490                        cal_data_diff =
 491                                calibration_data[0] - calibration_data[1];
 492                else
 493                        cal_data_diff =
 494                                calibration_data[1] - calibration_data[0];
 495
 496                if (((calibration_data[1] >= lower_threshold) &&
 497                     (calibration_data[1] <= upper_threshold) &&
 498                     (cal_data_diff <= ST_ADC_CALIBRATE_DIFF_THRESHOLD)) ||
 499                    (ddata->vendor == CPCAP_VENDOR_TI)) {
 500                        bank_conversion[channel].cal_offset =
 501                                ((short)calibration_data[1] * -1) + 512;
 502                        dev_dbg(ddata->dev, "ch%i calibration complete: %i\n",
 503                                channel, bank_conversion[channel].cal_offset);
 504                        break;
 505                }
 506                usleep_range(5000, 10000);
 507        }
 508
 509        return 0;
 510}
 511
 512static int cpcap_adc_calibrate(struct cpcap_adc *ddata)
 513{
 514        int error;
 515
 516        error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_CHG_ISENSE,
 517                                        CPCAP_REG_ADCAL1,
 518                                        ST_ADC_CAL_CHRGI_LOW_THRESHOLD,
 519                                        ST_ADC_CAL_CHRGI_HIGH_THRESHOLD);
 520        if (error)
 521                return error;
 522
 523        error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_BATTI,
 524                                        CPCAP_REG_ADCAL2,
 525                                        ST_ADC_CAL_BATTI_LOW_THRESHOLD,
 526                                        ST_ADC_CAL_BATTI_HIGH_THRESHOLD);
 527        if (error)
 528                return error;
 529
 530        return 0;
 531}
 532
 533/* ADC setup, read and scale functions */
 534static void cpcap_adc_setup_bank(struct cpcap_adc *ddata,
 535                                 struct cpcap_adc_request *req)
 536{
 537        const struct cpcap_adc_ato *ato = ddata->ato;
 538        unsigned short value1 = 0;
 539        unsigned short value2 = 0;
 540        int error;
 541
 542        if (!ato)
 543                return;
 544
 545        switch (req->channel) {
 546        case CPCAP_ADC_AD0:
 547                value2 |= CPCAP_BIT_THERMBIAS_EN;
 548                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 549                                           CPCAP_BIT_THERMBIAS_EN,
 550                                           value2);
 551                if (error)
 552                        return;
 553                usleep_range(800, 1000);
 554                break;
 555        case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
 556                value1 |= CPCAP_BIT_AD_SEL1;
 557                break;
 558        case CPCAP_ADC_BATTP_PI16 ... CPCAP_ADC_BATTI_PI17:
 559                value1 |= CPCAP_BIT_RAND1;
 560        default:
 561                break;
 562        }
 563
 564        switch (req->timing) {
 565        case CPCAP_ADC_TIMING_IN:
 566                value1 |= ato->ato_in;
 567                value1 |= ato->atox_in;
 568                value2 |= ato->adc_ps_factor_in;
 569                value2 |= ato->atox_ps_factor_in;
 570                break;
 571        case CPCAP_ADC_TIMING_OUT:
 572                value1 |= ato->ato_out;
 573                value1 |= ato->atox_out;
 574                value2 |= ato->adc_ps_factor_out;
 575                value2 |= ato->atox_ps_factor_out;
 576                break;
 577
 578        case CPCAP_ADC_TIMING_IMM:
 579        default:
 580                break;
 581        }
 582
 583        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 584                                   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
 585                                   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
 586                                   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
 587                                   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
 588                                   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
 589                                   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
 590                                   value1);
 591        if (error)
 592                return;
 593
 594        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 595                                   CPCAP_BIT_ATOX_PS_FACTOR |
 596                                   CPCAP_BIT_ADC_PS_FACTOR1 |
 597                                   CPCAP_BIT_ADC_PS_FACTOR0 |
 598                                   CPCAP_BIT_THERMBIAS_EN,
 599                                   value2);
 600        if (error)
 601                return;
 602
 603        if (req->timing == CPCAP_ADC_TIMING_IMM) {
 604                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 605                                           CPCAP_BIT_ADTRIG_DIS,
 606                                           CPCAP_BIT_ADTRIG_DIS);
 607                if (error)
 608                        return;
 609
 610                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 611                                           CPCAP_BIT_ASC,
 612                                           CPCAP_BIT_ASC);
 613                if (error)
 614                        return;
 615        } else {
 616                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 617                                           CPCAP_BIT_ADTRIG_ONESHOT,
 618                                           CPCAP_BIT_ADTRIG_ONESHOT);
 619                if (error)
 620                        return;
 621
 622                error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 623                                           CPCAP_BIT_ADTRIG_DIS, 0);
 624                if (error)
 625                        return;
 626        }
 627}
 628
 629static int cpcap_adc_start_bank(struct cpcap_adc *ddata,
 630                                struct cpcap_adc_request *req)
 631{
 632        int i, error;
 633
 634        req->timing = CPCAP_ADC_TIMING_IMM;
 635        ddata->done = false;
 636
 637        for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
 638                cpcap_adc_setup_bank(ddata, req);
 639                error = wait_event_interruptible_timeout(ddata->wq_data_avail,
 640                                                         ddata->done,
 641                                                         msecs_to_jiffies(50));
 642                if (error > 0)
 643                        return 0;
 644
 645                if (error == 0) {
 646                        error = -ETIMEDOUT;
 647                        continue;
 648                }
 649
 650                if (error < 0)
 651                        return error;
 652        }
 653
 654        return error;
 655}
 656
 657static int cpcap_adc_stop_bank(struct cpcap_adc *ddata)
 658{
 659        int error;
 660
 661        error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
 662                                   0xffff,
 663                                   CPCAP_REG_ADCC1_DEFAULTS);
 664        if (error)
 665                return error;
 666
 667        return regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
 668                                  0xffff,
 669                                  CPCAP_REG_ADCC2_DEFAULTS);
 670}
 671
 672static void cpcap_adc_phase(struct cpcap_adc_request *req)
 673{
 674        const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
 675        const struct cpcap_adc_phasing_tbl *phase_tbl = req->phase_tbl;
 676        int index = req->channel;
 677
 678        /* Remuxed channels 16 and 17 use BATTP and BATTI entries */
 679        switch (req->channel) {
 680        case CPCAP_ADC_BATTP:
 681        case CPCAP_ADC_BATTP_PI16:
 682                index = req->bank_index;
 683                req->result -= phase_tbl[index].offset;
 684                req->result -= CPCAP_FOUR_POINT_TWO_ADC;
 685                req->result *= phase_tbl[index].multiplier;
 686                if (phase_tbl[index].divider == 0)
 687                        return;
 688                req->result /= phase_tbl[index].divider;
 689                req->result += CPCAP_FOUR_POINT_TWO_ADC;
 690                break;
 691        case CPCAP_ADC_BATTI_PI17:
 692                index = req->bank_index;
 693                /* fallthrough */
 694        default:
 695                req->result += conv_tbl[index].cal_offset;
 696                req->result += conv_tbl[index].align_offset;
 697                req->result *= phase_tbl[index].multiplier;
 698                if (phase_tbl[index].divider == 0)
 699                        return;
 700                req->result /= phase_tbl[index].divider;
 701                req->result += phase_tbl[index].offset;
 702                break;
 703        }
 704
 705        if (req->result < phase_tbl[index].min)
 706                req->result = phase_tbl[index].min;
 707        else if (req->result > phase_tbl[index].max)
 708                req->result = phase_tbl[index].max;
 709}
 710
 711/* Looks up temperatures in a table and calculates averages if needed */
 712static int cpcap_adc_table_to_millicelcius(unsigned short value)
 713{
 714        int i, result = 0, alpha;
 715
 716        if (value <= temp_map[CPCAP_MAX_TEMP_LVL - 1][0])
 717                return temp_map[CPCAP_MAX_TEMP_LVL - 1][1];
 718
 719        if (value >= temp_map[0][0])
 720                return temp_map[0][1];
 721
 722        for (i = 0; i < CPCAP_MAX_TEMP_LVL - 1; i++) {
 723                if ((value <= temp_map[i][0]) &&
 724                    (value >= temp_map[i + 1][0])) {
 725                        if (value == temp_map[i][0]) {
 726                                result = temp_map[i][1];
 727                        } else if (value == temp_map[i + 1][0]) {
 728                                result = temp_map[i + 1][1];
 729                        } else {
 730                                alpha = ((value - temp_map[i][0]) * 1000) /
 731                                        (temp_map[i + 1][0] - temp_map[i][0]);
 732
 733                                result = temp_map[i][1] +
 734                                        ((alpha * (temp_map[i + 1][1] -
 735                                                 temp_map[i][1])) / 1000);
 736                        }
 737                        break;
 738                }
 739        }
 740
 741        return result;
 742}
 743
 744static void cpcap_adc_convert(struct cpcap_adc_request *req)
 745{
 746        const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
 747        int index = req->channel;
 748
 749        /* Remuxed channels 16 and 17 use BATTP and BATTI entries */
 750        switch (req->channel) {
 751        case CPCAP_ADC_BATTP_PI16:
 752                index = CPCAP_ADC_BATTP;
 753                break;
 754        case CPCAP_ADC_BATTI_PI17:
 755                index = CPCAP_ADC_BATTI;
 756                break;
 757        default:
 758                break;
 759        }
 760
 761        /* No conversion for raw channels */
 762        if (conv_tbl[index].conv_type == IIO_CHAN_INFO_RAW)
 763                return;
 764
 765        /* Temperatures use a lookup table instead of conversion table */
 766        if ((req->channel == CPCAP_ADC_AD0) ||
 767            (req->channel == CPCAP_ADC_AD3)) {
 768                req->result =
 769                        cpcap_adc_table_to_millicelcius(req->result);
 770
 771                return;
 772        }
 773
 774        /* All processed channels use a conversion table */
 775        req->result *= conv_tbl[index].multiplier;
 776        if (conv_tbl[index].divider == 0)
 777                return;
 778        req->result /= conv_tbl[index].divider;
 779        req->result += conv_tbl[index].conv_offset;
 780}
 781
 782/*
 783 * REVISIT: Check if timed sampling can use multiple channels at the
 784 * same time. If not, replace channel_mask with just channel.
 785 */
 786static int cpcap_adc_read_bank_scaled(struct cpcap_adc *ddata,
 787                                      struct cpcap_adc_request *req)
 788{
 789        int calibration_data, error, addr;
 790
 791        if (ddata->vendor == CPCAP_VENDOR_TI) {
 792                error = regmap_read(ddata->reg, CPCAP_REG_ADCAL1,
 793                                    &calibration_data);
 794                if (error)
 795                        return error;
 796                bank_conversion[CPCAP_ADC_CHG_ISENSE].cal_offset =
 797                        ((short)calibration_data * -1) + 512;
 798
 799                error = regmap_read(ddata->reg, CPCAP_REG_ADCAL2,
 800                                    &calibration_data);
 801                if (error)
 802                        return error;
 803                bank_conversion[CPCAP_ADC_BATTI].cal_offset =
 804                        ((short)calibration_data * -1) + 512;
 805        }
 806
 807        addr = CPCAP_REG_ADCD0 + req->bank_index * 4;
 808
 809        error = regmap_read(ddata->reg, addr, &req->result);
 810        if (error)
 811                return error;
 812
 813        req->result &= 0x3ff;
 814        cpcap_adc_phase(req);
 815        cpcap_adc_convert(req);
 816
 817        return 0;
 818}
 819
 820static int cpcap_adc_init_request(struct cpcap_adc_request *req,
 821                                  int channel)
 822{
 823        req->channel = channel;
 824        req->phase_tbl = bank_phasing;
 825        req->conv_tbl = bank_conversion;
 826
 827        switch (channel) {
 828        case CPCAP_ADC_AD0 ... CPCAP_ADC_USB_ID:
 829                req->bank_index = channel;
 830                break;
 831        case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
 832                req->bank_index = channel - 8;
 833                break;
 834        case CPCAP_ADC_BATTP_PI16:
 835                req->bank_index = CPCAP_ADC_BATTP;
 836                break;
 837        case CPCAP_ADC_BATTI_PI17:
 838                req->bank_index = CPCAP_ADC_BATTI;
 839                break;
 840        default:
 841                return -EINVAL;
 842        }
 843
 844        return 0;
 845}
 846
 847static int cpcap_adc_read_st_die_temp(struct cpcap_adc *ddata,
 848                                      int addr, int *val)
 849{
 850        int error;
 851
 852        error = regmap_read(ddata->reg, addr, val);
 853        if (error)
 854                return error;
 855
 856        *val -= 282;
 857        *val *= 114;
 858        *val += 25000;
 859
 860        return 0;
 861}
 862
 863static int cpcap_adc_read(struct iio_dev *indio_dev,
 864                          struct iio_chan_spec const *chan,
 865                          int *val, int *val2, long mask)
 866{
 867        struct cpcap_adc *ddata = iio_priv(indio_dev);
 868        struct cpcap_adc_request req;
 869        int error;
 870
 871        error = cpcap_adc_init_request(&req, chan->channel);
 872        if (error)
 873                return error;
 874
 875        switch (mask) {
 876        case IIO_CHAN_INFO_RAW:
 877                mutex_lock(&ddata->lock);
 878                error = cpcap_adc_start_bank(ddata, &req);
 879                if (error)
 880                        goto err_unlock;
 881                error = regmap_read(ddata->reg, chan->address, val);
 882                if (error)
 883                        goto err_unlock;
 884                error = cpcap_adc_stop_bank(ddata);
 885                if (error)
 886                        goto err_unlock;
 887                mutex_unlock(&ddata->lock);
 888                break;
 889        case IIO_CHAN_INFO_PROCESSED:
 890                mutex_lock(&ddata->lock);
 891                error = cpcap_adc_start_bank(ddata, &req);
 892                if (error)
 893                        goto err_unlock;
 894                if ((ddata->vendor == CPCAP_VENDOR_ST) &&
 895                    (chan->channel == CPCAP_ADC_AD3)) {
 896                        error = cpcap_adc_read_st_die_temp(ddata,
 897                                                           chan->address,
 898                                                           &req.result);
 899                        if (error)
 900                                goto err_unlock;
 901                } else {
 902                        error = cpcap_adc_read_bank_scaled(ddata, &req);
 903                        if (error)
 904                                goto err_unlock;
 905                }
 906                error = cpcap_adc_stop_bank(ddata);
 907                if (error)
 908                        goto err_unlock;
 909                mutex_unlock(&ddata->lock);
 910                *val = req.result;
 911                break;
 912        default:
 913                return -EINVAL;
 914        }
 915
 916        return IIO_VAL_INT;
 917
 918err_unlock:
 919        mutex_unlock(&ddata->lock);
 920        dev_err(ddata->dev, "error reading ADC: %i\n", error);
 921
 922        return error;
 923}
 924
 925static const struct iio_info cpcap_adc_info = {
 926        .read_raw = &cpcap_adc_read,
 927};
 928
 929/*
 930 * Configuration for Motorola mapphone series such as droid 4.
 931 * Copied from the Motorola mapphone kernel tree.
 932 */
 933static const struct cpcap_adc_ato mapphone_adc = {
 934        .ato_in = 0x0480,
 935        .atox_in = 0,
 936        .adc_ps_factor_in = 0x0200,
 937        .atox_ps_factor_in = 0,
 938        .ato_out = 0,
 939        .atox_out = 0,
 940        .adc_ps_factor_out = 0,
 941        .atox_ps_factor_out = 0,
 942};
 943
 944static const struct of_device_id cpcap_adc_id_table[] = {
 945        {
 946                .compatible = "motorola,cpcap-adc",
 947        },
 948        {
 949                .compatible = "motorola,mapphone-cpcap-adc",
 950                .data = &mapphone_adc,
 951        },
 952        { /* sentinel */ },
 953};
 954MODULE_DEVICE_TABLE(of, cpcap_adc_id_table);
 955
 956static int cpcap_adc_probe(struct platform_device *pdev)
 957{
 958        const struct of_device_id *match;
 959        struct cpcap_adc *ddata;
 960        struct iio_dev *indio_dev;
 961        int error;
 962
 963        match = of_match_device(of_match_ptr(cpcap_adc_id_table),
 964                                &pdev->dev);
 965        if (!match)
 966                return -EINVAL;
 967
 968        if (!match->data) {
 969                dev_err(&pdev->dev, "no configuration data found\n");
 970
 971                return -ENODEV;
 972        }
 973
 974        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ddata));
 975        if (!indio_dev) {
 976                dev_err(&pdev->dev, "failed to allocate iio device\n");
 977
 978                return -ENOMEM;
 979        }
 980        ddata = iio_priv(indio_dev);
 981        ddata->ato = match->data;
 982        ddata->dev = &pdev->dev;
 983
 984        mutex_init(&ddata->lock);
 985        init_waitqueue_head(&ddata->wq_data_avail);
 986
 987        indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 988        indio_dev->dev.parent = &pdev->dev;
 989        indio_dev->dev.of_node = pdev->dev.of_node;
 990        indio_dev->channels = cpcap_adc_channels;
 991        indio_dev->num_channels = ARRAY_SIZE(cpcap_adc_channels);
 992        indio_dev->name = dev_name(&pdev->dev);
 993        indio_dev->info = &cpcap_adc_info;
 994
 995        ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
 996        if (!ddata->reg)
 997                return -ENODEV;
 998
 999        error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
1000        if (error)
1001                return error;
1002
1003        platform_set_drvdata(pdev, indio_dev);
1004
1005        ddata->irq = platform_get_irq_byname(pdev, "adcdone");
1006        if (ddata->irq < 0)
1007                return -ENODEV;
1008
1009        error = devm_request_threaded_irq(&pdev->dev, ddata->irq, NULL,
1010                                          cpcap_adc_irq_thread,
1011                                          IRQF_TRIGGER_NONE,
1012                                          "cpcap-adc", indio_dev);
1013        if (error) {
1014                dev_err(&pdev->dev, "could not get irq: %i\n",
1015                        error);
1016
1017                return error;
1018        }
1019
1020        error = cpcap_adc_calibrate(ddata);
1021        if (error)
1022                return error;
1023
1024        dev_info(&pdev->dev, "CPCAP ADC device probed\n");
1025
1026        return devm_iio_device_register(&pdev->dev, indio_dev);
1027}
1028
1029static struct platform_driver cpcap_adc_driver = {
1030        .driver = {
1031                .name = "cpcap_adc",
1032                .of_match_table = of_match_ptr(cpcap_adc_id_table),
1033        },
1034        .probe = cpcap_adc_probe,
1035};
1036
1037module_platform_driver(cpcap_adc_driver);
1038
1039MODULE_ALIAS("platform:cpcap_adc");
1040MODULE_DESCRIPTION("CPCAP ADC driver");
1041MODULE_AUTHOR("Tony Lindgren <tony@atomide.com");
1042MODULE_LICENSE("GPL v2");
1043