linux/drivers/mfd/ab8500-gpadc.c
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   1/*
   2 * Copyright (C) ST-Ericsson SA 2010
   3 *
   4 * License Terms: GNU General Public License v2
   5 * Author: Arun R Murthy <arun.murthy@stericsson.com>
   6 * Author: Daniel Willerud <daniel.willerud@stericsson.com>
   7 * Author: Johan Palsson <johan.palsson@stericsson.com>
   8 */
   9#include <linux/init.h>
  10#include <linux/module.h>
  11#include <linux/device.h>
  12#include <linux/interrupt.h>
  13#include <linux/spinlock.h>
  14#include <linux/delay.h>
  15#include <linux/pm_runtime.h>
  16#include <linux/platform_device.h>
  17#include <linux/completion.h>
  18#include <linux/regulator/consumer.h>
  19#include <linux/err.h>
  20#include <linux/slab.h>
  21#include <linux/list.h>
  22#include <linux/mfd/abx500.h>
  23#include <linux/mfd/abx500/ab8500.h>
  24#include <linux/mfd/abx500/ab8500-gpadc.h>
  25
  26/*
  27 * GPADC register offsets
  28 * Bank : 0x0A
  29 */
  30#define AB8500_GPADC_CTRL1_REG          0x00
  31#define AB8500_GPADC_CTRL2_REG          0x01
  32#define AB8500_GPADC_CTRL3_REG          0x02
  33#define AB8500_GPADC_AUTO_TIMER_REG     0x03
  34#define AB8500_GPADC_STAT_REG           0x04
  35#define AB8500_GPADC_MANDATAL_REG       0x05
  36#define AB8500_GPADC_MANDATAH_REG       0x06
  37#define AB8500_GPADC_AUTODATAL_REG      0x07
  38#define AB8500_GPADC_AUTODATAH_REG      0x08
  39#define AB8500_GPADC_MUX_CTRL_REG       0x09
  40
  41/*
  42 * OTP register offsets
  43 * Bank : 0x15
  44 */
  45#define AB8500_GPADC_CAL_1              0x0F
  46#define AB8500_GPADC_CAL_2              0x10
  47#define AB8500_GPADC_CAL_3              0x11
  48#define AB8500_GPADC_CAL_4              0x12
  49#define AB8500_GPADC_CAL_5              0x13
  50#define AB8500_GPADC_CAL_6              0x14
  51#define AB8500_GPADC_CAL_7              0x15
  52
  53/* gpadc constants */
  54#define EN_VINTCORE12                   0x04
  55#define EN_VTVOUT                       0x02
  56#define EN_GPADC                        0x01
  57#define DIS_GPADC                       0x00
  58#define SW_AVG_16                       0x60
  59#define ADC_SW_CONV                     0x04
  60#define EN_ICHAR                        0x80
  61#define BTEMP_PULL_UP                   0x08
  62#define EN_BUF                          0x40
  63#define DIS_ZERO                        0x00
  64#define GPADC_BUSY                      0x01
  65
  66/* GPADC constants from AB8500 spec, UM0836 */
  67#define ADC_RESOLUTION                  1024
  68#define ADC_CH_BTEMP_MIN                0
  69#define ADC_CH_BTEMP_MAX                1350
  70#define ADC_CH_DIETEMP_MIN              0
  71#define ADC_CH_DIETEMP_MAX              1350
  72#define ADC_CH_CHG_V_MIN                0
  73#define ADC_CH_CHG_V_MAX                20030
  74#define ADC_CH_ACCDET2_MIN              0
  75#define ADC_CH_ACCDET2_MAX              2500
  76#define ADC_CH_VBAT_MIN                 2300
  77#define ADC_CH_VBAT_MAX                 4800
  78#define ADC_CH_CHG_I_MIN                0
  79#define ADC_CH_CHG_I_MAX                1500
  80#define ADC_CH_BKBAT_MIN                0
  81#define ADC_CH_BKBAT_MAX                3200
  82
  83/* This is used to not lose precision when dividing to get gain and offset */
  84#define CALIB_SCALE                     1000
  85
  86/* Time in ms before disabling regulator */
  87#define GPADC_AUDOSUSPEND_DELAY         1
  88
  89#define CONVERSION_TIME                 500 /* ms */
  90
  91enum cal_channels {
  92        ADC_INPUT_VMAIN = 0,
  93        ADC_INPUT_BTEMP,
  94        ADC_INPUT_VBAT,
  95        NBR_CAL_INPUTS,
  96};
  97
  98/**
  99 * struct adc_cal_data - Table for storing gain and offset for the calibrated
 100 * ADC channels
 101 * @gain:               Gain of the ADC channel
 102 * @offset:             Offset of the ADC channel
 103 */
 104struct adc_cal_data {
 105        u64 gain;
 106        u64 offset;
 107};
 108
 109/**
 110 * struct ab8500_gpadc - AB8500 GPADC device information
 111 * @dev:                        pointer to the struct device
 112 * @node:                       a list of AB8500 GPADCs, hence prepared for
 113                                reentrance
 114 * @parent:                     pointer to the struct ab8500
 115 * @ab8500_gpadc_complete:      pointer to the struct completion, to indicate
 116 *                              the completion of gpadc conversion
 117 * @ab8500_gpadc_lock:          structure of type mutex
 118 * @regu:                       pointer to the struct regulator
 119 * @irq:                        interrupt number that is used by gpadc
 120 * @cal_data                    array of ADC calibration data structs
 121 */
 122struct ab8500_gpadc {
 123        struct device *dev;
 124        struct list_head node;
 125        struct ab8500 *parent;
 126        struct completion ab8500_gpadc_complete;
 127        struct mutex ab8500_gpadc_lock;
 128        struct regulator *regu;
 129        int irq;
 130        struct adc_cal_data cal_data[NBR_CAL_INPUTS];
 131};
 132
 133static LIST_HEAD(ab8500_gpadc_list);
 134
 135/**
 136 * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
 137 * (i.e. the first GPADC in the instance list)
 138 */
 139struct ab8500_gpadc *ab8500_gpadc_get(char *name)
 140{
 141        struct ab8500_gpadc *gpadc;
 142
 143        list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
 144                if (!strcmp(name, dev_name(gpadc->dev)))
 145                    return gpadc;
 146        }
 147
 148        return ERR_PTR(-ENOENT);
 149}
 150EXPORT_SYMBOL(ab8500_gpadc_get);
 151
 152/**
 153 * ab8500_gpadc_ad_to_voltage() - Convert a raw ADC value to a voltage
 154 */
 155int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 channel,
 156        int ad_value)
 157{
 158        int res;
 159
 160        switch (channel) {
 161        case MAIN_CHARGER_V:
 162                /* For some reason we don't have calibrated data */
 163                if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) {
 164                        res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX -
 165                                ADC_CH_CHG_V_MIN) * ad_value /
 166                                ADC_RESOLUTION;
 167                        break;
 168                }
 169                /* Here we can use the calibrated data */
 170                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain +
 171                        gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE;
 172                break;
 173
 174        case BAT_CTRL:
 175        case BTEMP_BALL:
 176        case ACC_DETECT1:
 177        case ADC_AUX1:
 178        case ADC_AUX2:
 179                /* For some reason we don't have calibrated data */
 180                if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) {
 181                        res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX -
 182                                ADC_CH_BTEMP_MIN) * ad_value /
 183                                ADC_RESOLUTION;
 184                        break;
 185                }
 186                /* Here we can use the calibrated data */
 187                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain +
 188                        gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE;
 189                break;
 190
 191        case MAIN_BAT_V:
 192                /* For some reason we don't have calibrated data */
 193                if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) {
 194                        res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX -
 195                                ADC_CH_VBAT_MIN) * ad_value /
 196                                ADC_RESOLUTION;
 197                        break;
 198                }
 199                /* Here we can use the calibrated data */
 200                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain +
 201                        gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE;
 202                break;
 203
 204        case DIE_TEMP:
 205                res = ADC_CH_DIETEMP_MIN +
 206                        (ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value /
 207                        ADC_RESOLUTION;
 208                break;
 209
 210        case ACC_DETECT2:
 211                res = ADC_CH_ACCDET2_MIN +
 212                        (ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value /
 213                        ADC_RESOLUTION;
 214                break;
 215
 216        case VBUS_V:
 217                res = ADC_CH_CHG_V_MIN +
 218                        (ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value /
 219                        ADC_RESOLUTION;
 220                break;
 221
 222        case MAIN_CHARGER_C:
 223        case USB_CHARGER_C:
 224                res = ADC_CH_CHG_I_MIN +
 225                        (ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value /
 226                        ADC_RESOLUTION;
 227                break;
 228
 229        case BK_BAT_V:
 230                res = ADC_CH_BKBAT_MIN +
 231                        (ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value /
 232                        ADC_RESOLUTION;
 233                break;
 234
 235        default:
 236                dev_err(gpadc->dev,
 237                        "unknown channel, not possible to convert\n");
 238                res = -EINVAL;
 239                break;
 240
 241        }
 242        return res;
 243}
 244EXPORT_SYMBOL(ab8500_gpadc_ad_to_voltage);
 245
 246/**
 247 * ab8500_gpadc_convert() - gpadc conversion
 248 * @channel:    analog channel to be converted to digital data
 249 *
 250 * This function converts the selected analog i/p to digital
 251 * data.
 252 */
 253int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 channel)
 254{
 255        int ad_value;
 256        int voltage;
 257
 258        ad_value = ab8500_gpadc_read_raw(gpadc, channel);
 259        if (ad_value < 0) {
 260                dev_err(gpadc->dev, "GPADC raw value failed ch: %d\n", channel);
 261                return ad_value;
 262        }
 263
 264        voltage = ab8500_gpadc_ad_to_voltage(gpadc, channel, ad_value);
 265
 266        if (voltage < 0)
 267                dev_err(gpadc->dev, "GPADC to voltage conversion failed ch:"
 268                        " %d AD: 0x%x\n", channel, ad_value);
 269
 270        return voltage;
 271}
 272EXPORT_SYMBOL(ab8500_gpadc_convert);
 273
 274/**
 275 * ab8500_gpadc_read_raw() - gpadc read
 276 * @channel:    analog channel to be read
 277 *
 278 * This function obtains the raw ADC value, this then needs
 279 * to be converted by calling ab8500_gpadc_ad_to_voltage()
 280 */
 281int ab8500_gpadc_read_raw(struct ab8500_gpadc *gpadc, u8 channel)
 282{
 283        int ret;
 284        int looplimit = 0;
 285        u8 val, low_data, high_data;
 286
 287        if (!gpadc)
 288                return -ENODEV;
 289
 290        mutex_lock(&gpadc->ab8500_gpadc_lock);
 291
 292        /* Enable VTVout LDO this is required for GPADC */
 293        pm_runtime_get_sync(gpadc->dev);
 294
 295        /* Check if ADC is not busy, lock and proceed */
 296        do {
 297                ret = abx500_get_register_interruptible(gpadc->dev,
 298                        AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
 299                if (ret < 0)
 300                        goto out;
 301                if (!(val & GPADC_BUSY))
 302                        break;
 303                msleep(10);
 304        } while (++looplimit < 10);
 305        if (looplimit >= 10 && (val & GPADC_BUSY)) {
 306                dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
 307                ret = -EINVAL;
 308                goto out;
 309        }
 310
 311        /* Enable GPADC */
 312        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 313                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
 314        if (ret < 0) {
 315                dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
 316                goto out;
 317        }
 318
 319        /* Select the channel source and set average samples to 16 */
 320        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 321                AB8500_GPADC_CTRL2_REG, (channel | SW_AVG_16));
 322        if (ret < 0) {
 323                dev_err(gpadc->dev,
 324                        "gpadc_conversion: set avg samples failed\n");
 325                goto out;
 326        }
 327
 328        /*
 329         * Enable ADC, buffering, select rising edge and enable ADC path
 330         * charging current sense if it needed, ABB 3.0 needs some special
 331         * treatment too.
 332         */
 333        switch (channel) {
 334        case MAIN_CHARGER_C:
 335        case USB_CHARGER_C:
 336                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 337                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
 338                        EN_BUF | EN_ICHAR,
 339                        EN_BUF | EN_ICHAR);
 340                break;
 341        case BTEMP_BALL:
 342                if (!is_ab8500_2p0_or_earlier(gpadc->parent)) {
 343                        /* Turn on btemp pull-up on ABB 3.0 */
 344                        ret = abx500_mask_and_set_register_interruptible(
 345                                gpadc->dev,
 346                                AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
 347                                EN_BUF | BTEMP_PULL_UP,
 348                                EN_BUF | BTEMP_PULL_UP);
 349
 350                 /*
 351                  * Delay might be needed for ABB8500 cut 3.0, if not, remove
 352                  * when hardware will be available
 353                  */
 354                        usleep_range(1000, 1000);
 355                        break;
 356                }
 357                /* Intentional fallthrough */
 358        default:
 359                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 360                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
 361                break;
 362        }
 363        if (ret < 0) {
 364                dev_err(gpadc->dev,
 365                        "gpadc_conversion: select falling edge failed\n");
 366                goto out;
 367        }
 368
 369        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 370                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
 371        if (ret < 0) {
 372                dev_err(gpadc->dev,
 373                        "gpadc_conversion: start s/w conversion failed\n");
 374                goto out;
 375        }
 376        /* wait for completion of conversion */
 377        if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete,
 378                                         msecs_to_jiffies(CONVERSION_TIME))) {
 379                dev_err(gpadc->dev,
 380                        "timeout: didn't receive GPADC conversion interrupt\n");
 381                ret = -EINVAL;
 382                goto out;
 383        }
 384
 385        /* Read the converted RAW data */
 386        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 387                AB8500_GPADC_MANDATAL_REG, &low_data);
 388        if (ret < 0) {
 389                dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
 390                goto out;
 391        }
 392
 393        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 394                AB8500_GPADC_MANDATAH_REG, &high_data);
 395        if (ret < 0) {
 396                dev_err(gpadc->dev,
 397                        "gpadc_conversion: read high data failed\n");
 398                goto out;
 399        }
 400
 401        /* Disable GPADC */
 402        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 403                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 404        if (ret < 0) {
 405                dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
 406                goto out;
 407        }
 408
 409        pm_runtime_mark_last_busy(gpadc->dev);
 410        pm_runtime_put_autosuspend(gpadc->dev);
 411
 412        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 413
 414        return (high_data << 8) | low_data;
 415
 416out:
 417        /*
 418         * It has shown to be needed to turn off the GPADC if an error occurs,
 419         * otherwise we might have problem when waiting for the busy bit in the
 420         * GPADC status register to go low. In V1.1 there wait_for_completion
 421         * seems to timeout when waiting for an interrupt.. Not seen in V2.0
 422         */
 423        (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 424                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 425
 426        pm_runtime_put(gpadc->dev);
 427
 428        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 429        dev_err(gpadc->dev,
 430                "gpadc_conversion: Failed to AD convert channel %d\n", channel);
 431        return ret;
 432}
 433EXPORT_SYMBOL(ab8500_gpadc_read_raw);
 434
 435/**
 436 * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
 437 * @irq:        irq number
 438 * @data:       pointer to the data passed during request irq
 439 *
 440 * This is a interrupt service routine for s/w gpadc conversion completion.
 441 * Notifies the gpadc completion is completed and the converted raw value
 442 * can be read from the registers.
 443 * Returns IRQ status(IRQ_HANDLED)
 444 */
 445static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
 446{
 447        struct ab8500_gpadc *gpadc = _gpadc;
 448
 449        complete(&gpadc->ab8500_gpadc_complete);
 450
 451        return IRQ_HANDLED;
 452}
 453
 454static int otp_cal_regs[] = {
 455        AB8500_GPADC_CAL_1,
 456        AB8500_GPADC_CAL_2,
 457        AB8500_GPADC_CAL_3,
 458        AB8500_GPADC_CAL_4,
 459        AB8500_GPADC_CAL_5,
 460        AB8500_GPADC_CAL_6,
 461        AB8500_GPADC_CAL_7,
 462};
 463
 464static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
 465{
 466        int i;
 467        int ret[ARRAY_SIZE(otp_cal_regs)];
 468        u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];
 469
 470        int vmain_high, vmain_low;
 471        int btemp_high, btemp_low;
 472        int vbat_high, vbat_low;
 473
 474        /* First we read all OTP registers and store the error code */
 475        for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
 476                ret[i] = abx500_get_register_interruptible(gpadc->dev,
 477                        AB8500_OTP_EMUL, otp_cal_regs[i],  &gpadc_cal[i]);
 478                if (ret[i] < 0)
 479                        dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
 480                                __func__, otp_cal_regs[i]);
 481        }
 482
 483        /*
 484         * The ADC calibration data is stored in OTP registers.
 485         * The layout of the calibration data is outlined below and a more
 486         * detailed description can be found in UM0836
 487         *
 488         * vm_h/l = vmain_high/low
 489         * bt_h/l = btemp_high/low
 490         * vb_h/l = vbat_high/low
 491         *
 492         * Data bits:
 493         * | 7     | 6     | 5     | 4     | 3     | 2     | 1     | 0
 494         * |.......|.......|.......|.......|.......|.......|.......|.......
 495         * |                                               | vm_h9 | vm_h8
 496         * |.......|.......|.......|.......|.......|.......|.......|.......
 497         * |               | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
 498         * |.......|.......|.......|.......|.......|.......|.......|.......
 499         * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
 500         * |.......|.......|.......|.......|.......|.......|.......|.......
 501         * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
 502         * |.......|.......|.......|.......|.......|.......|.......|.......
 503         * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
 504         * |.......|.......|.......|.......|.......|.......|.......|.......
 505         * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
 506         * |.......|.......|.......|.......|.......|.......|.......|.......
 507         * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
 508         * |.......|.......|.......|.......|.......|.......|.......|.......
 509         *
 510         *
 511         * Ideal output ADC codes corresponding to injected input voltages
 512         * during manufacturing is:
 513         *
 514         * vmain_high: Vin = 19500mV / ADC ideal code = 997
 515         * vmain_low:  Vin = 315mV   / ADC ideal code = 16
 516         * btemp_high: Vin = 1300mV  / ADC ideal code = 985
 517         * btemp_low:  Vin = 21mV    / ADC ideal code = 16
 518         * vbat_high:  Vin = 4700mV  / ADC ideal code = 982
 519         * vbat_low:   Vin = 2380mV  / ADC ideal code = 33
 520         */
 521
 522        /* Calculate gain and offset for VMAIN if all reads succeeded */
 523        if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
 524                vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
 525                        ((gpadc_cal[1] & 0x3F) << 2) |
 526                        ((gpadc_cal[2] & 0xC0) >> 6));
 527
 528                vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);
 529
 530                gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE *
 531                        (19500 - 315) / (vmain_high - vmain_low);
 532
 533                gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 -
 534                        (CALIB_SCALE * (19500 - 315) /
 535                         (vmain_high - vmain_low)) * vmain_high;
 536        } else {
 537                gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0;
 538        }
 539
 540        /* Calculate gain and offset for BTEMP if all reads succeeded */
 541        if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
 542                btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
 543                        (gpadc_cal[3] << 1) |
 544                        ((gpadc_cal[4] & 0x80) >> 7));
 545
 546                btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);
 547
 548                gpadc->cal_data[ADC_INPUT_BTEMP].gain =
 549                        CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);
 550
 551                gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 -
 552                        (CALIB_SCALE * (1300 - 21) /
 553                        (btemp_high - btemp_low)) * btemp_high;
 554        } else {
 555                gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0;
 556        }
 557
 558        /* Calculate gain and offset for VBAT if all reads succeeded */
 559        if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
 560                vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
 561                vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);
 562
 563                gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE *
 564                        (4700 - 2380) / (vbat_high - vbat_low);
 565
 566                gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 -
 567                        (CALIB_SCALE * (4700 - 2380) /
 568                        (vbat_high - vbat_low)) * vbat_high;
 569        } else {
 570                gpadc->cal_data[ADC_INPUT_VBAT].gain = 0;
 571        }
 572
 573        dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n",
 574                gpadc->cal_data[ADC_INPUT_VMAIN].gain,
 575                gpadc->cal_data[ADC_INPUT_VMAIN].offset);
 576
 577        dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n",
 578                gpadc->cal_data[ADC_INPUT_BTEMP].gain,
 579                gpadc->cal_data[ADC_INPUT_BTEMP].offset);
 580
 581        dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n",
 582                gpadc->cal_data[ADC_INPUT_VBAT].gain,
 583                gpadc->cal_data[ADC_INPUT_VBAT].offset);
 584}
 585
 586static int ab8500_gpadc_runtime_suspend(struct device *dev)
 587{
 588        struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
 589
 590        regulator_disable(gpadc->regu);
 591        return 0;
 592}
 593
 594static int ab8500_gpadc_runtime_resume(struct device *dev)
 595{
 596        struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
 597        int ret;
 598
 599        ret = regulator_enable(gpadc->regu);
 600        if (ret)
 601                dev_err(dev, "Failed to enable vtvout LDO: %d\n", ret);
 602        return ret;
 603}
 604
 605static int ab8500_gpadc_runtime_idle(struct device *dev)
 606{
 607        pm_runtime_suspend(dev);
 608        return 0;
 609}
 610
 611static int ab8500_gpadc_probe(struct platform_device *pdev)
 612{
 613        int ret = 0;
 614        struct ab8500_gpadc *gpadc;
 615
 616        gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
 617        if (!gpadc) {
 618                dev_err(&pdev->dev, "Error: No memory\n");
 619                return -ENOMEM;
 620        }
 621
 622        gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
 623        if (gpadc->irq < 0) {
 624                dev_err(&pdev->dev, "failed to get platform irq-%d\n",
 625                        gpadc->irq);
 626                ret = gpadc->irq;
 627                goto fail;
 628        }
 629
 630        gpadc->dev = &pdev->dev;
 631        gpadc->parent = dev_get_drvdata(pdev->dev.parent);
 632        mutex_init(&gpadc->ab8500_gpadc_lock);
 633
 634        /* Initialize completion used to notify completion of conversion */
 635        init_completion(&gpadc->ab8500_gpadc_complete);
 636
 637        /* Register interrupt  - SwAdcComplete */
 638        ret = request_threaded_irq(gpadc->irq, NULL,
 639                ab8500_bm_gpswadcconvend_handler,
 640                IRQF_ONESHOT | IRQF_NO_SUSPEND | IRQF_SHARED,
 641                                "ab8500-gpadc", gpadc);
 642        if (ret < 0) {
 643                dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
 644                        gpadc->irq);
 645                goto fail;
 646        }
 647
 648        /* VTVout LDO used to power up ab8500-GPADC */
 649        gpadc->regu = devm_regulator_get(&pdev->dev, "vddadc");
 650        if (IS_ERR(gpadc->regu)) {
 651                ret = PTR_ERR(gpadc->regu);
 652                dev_err(gpadc->dev, "failed to get vtvout LDO\n");
 653                goto fail_irq;
 654        }
 655
 656        platform_set_drvdata(pdev, gpadc);
 657
 658        ret = regulator_enable(gpadc->regu);
 659        if (ret) {
 660                dev_err(gpadc->dev, "Failed to enable vtvout LDO: %d\n", ret);
 661                goto fail_enable;
 662        }
 663
 664        pm_runtime_set_autosuspend_delay(gpadc->dev, GPADC_AUDOSUSPEND_DELAY);
 665        pm_runtime_use_autosuspend(gpadc->dev);
 666        pm_runtime_set_active(gpadc->dev);
 667        pm_runtime_enable(gpadc->dev);
 668
 669        ab8500_gpadc_read_calibration_data(gpadc);
 670        list_add_tail(&gpadc->node, &ab8500_gpadc_list);
 671        dev_dbg(gpadc->dev, "probe success\n");
 672        return 0;
 673
 674fail_enable:
 675fail_irq:
 676        free_irq(gpadc->irq, gpadc);
 677fail:
 678        kfree(gpadc);
 679        gpadc = NULL;
 680        return ret;
 681}
 682
 683static int ab8500_gpadc_remove(struct platform_device *pdev)
 684{
 685        struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
 686
 687        /* remove this gpadc entry from the list */
 688        list_del(&gpadc->node);
 689        /* remove interrupt  - completion of Sw ADC conversion */
 690        free_irq(gpadc->irq, gpadc);
 691
 692        pm_runtime_get_sync(gpadc->dev);
 693        pm_runtime_disable(gpadc->dev);
 694
 695        regulator_disable(gpadc->regu);
 696
 697        pm_runtime_set_suspended(gpadc->dev);
 698
 699        pm_runtime_put_noidle(gpadc->dev);
 700
 701        kfree(gpadc);
 702        gpadc = NULL;
 703        return 0;
 704}
 705
 706static const struct dev_pm_ops ab8500_gpadc_pm_ops = {
 707        SET_RUNTIME_PM_OPS(ab8500_gpadc_runtime_suspend,
 708                           ab8500_gpadc_runtime_resume,
 709                           ab8500_gpadc_runtime_idle)
 710};
 711
 712static struct platform_driver ab8500_gpadc_driver = {
 713        .probe = ab8500_gpadc_probe,
 714        .remove = ab8500_gpadc_remove,
 715        .driver = {
 716                .name = "ab8500-gpadc",
 717                .owner = THIS_MODULE,
 718                .pm = &ab8500_gpadc_pm_ops,
 719        },
 720};
 721
 722static int __init ab8500_gpadc_init(void)
 723{
 724        return platform_driver_register(&ab8500_gpadc_driver);
 725}
 726
 727static void __exit ab8500_gpadc_exit(void)
 728{
 729        platform_driver_unregister(&ab8500_gpadc_driver);
 730}
 731
 732subsys_initcall_sync(ab8500_gpadc_init);
 733module_exit(ab8500_gpadc_exit);
 734
 735MODULE_LICENSE("GPL v2");
 736MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
 737MODULE_ALIAS("platform:ab8500_gpadc");
 738MODULE_DESCRIPTION("AB8500 GPADC driver");
 739
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