LXR linux/drivers/mfd/ab8500-gpadc.c

   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/platform_device.h>
  16#include <linux/completion.h>
  17#include <linux/regulator/consumer.h>
  18#include <linux/err.h>
  19#include <linux/slab.h>
  20#include <linux/list.h>
  21#include <linux/mfd/ab8500.h>
  22#include <linux/mfd/abx500.h>
  23#include <linux/mfd/ab8500/gpadc.h>
  24
  25/*
  26 * GPADC register offsets
  27 * Bank : 0x0A
  28 */
  29#define AB8500_GPADC_CTRL1_REG          0x00
  30#define AB8500_GPADC_CTRL2_REG          0x01
  31#define AB8500_GPADC_CTRL3_REG          0x02
  32#define AB8500_GPADC_AUTO_TIMER_REG     0x03
  33#define AB8500_GPADC_STAT_REG           0x04
  34#define AB8500_GPADC_MANDATAL_REG       0x05
  35#define AB8500_GPADC_MANDATAH_REG       0x06
  36#define AB8500_GPADC_AUTODATAL_REG      0x07
  37#define AB8500_GPADC_AUTODATAH_REG      0x08
  38#define AB8500_GPADC_MUX_CTRL_REG       0x09
  39
  40/*
  41 * OTP register offsets
  42 * Bank : 0x15
  43 */
  44#define AB8500_GPADC_CAL_1              0x0F
  45#define AB8500_GPADC_CAL_2              0x10
  46#define AB8500_GPADC_CAL_3              0x11
  47#define AB8500_GPADC_CAL_4              0x12
  48#define AB8500_GPADC_CAL_5              0x13
  49#define AB8500_GPADC_CAL_6              0x14
  50#define AB8500_GPADC_CAL_7              0x15
  51
  52/* gpadc constants */
  53#define EN_VINTCORE12                   0x04
  54#define EN_VTVOUT                       0x02
  55#define EN_GPADC                        0x01
  56#define DIS_GPADC                       0x00
  57#define SW_AVG_16                       0x60
  58#define ADC_SW_CONV                     0x04
  59#define EN_ICHAR                        0x80
  60#define EN_BUF                          0x40
  61#define DIS_ZERO                        0x00
  62#define GPADC_BUSY                      0x01
  63
  64/* GPADC constants from AB8500 spec, UM0836 */
  65#define ADC_RESOLUTION                  1024
  66#define ADC_CH_BTEMP_MIN                0
  67#define ADC_CH_BTEMP_MAX                1350
  68#define ADC_CH_DIETEMP_MIN              0
  69#define ADC_CH_DIETEMP_MAX              1350
  70#define ADC_CH_CHG_V_MIN                0
  71#define ADC_CH_CHG_V_MAX                20030
  72#define ADC_CH_ACCDET2_MIN              0
  73#define ADC_CH_ACCDET2_MAX              2500
  74#define ADC_CH_VBAT_MIN                 2300
  75#define ADC_CH_VBAT_MAX                 4800
  76#define ADC_CH_CHG_I_MIN                0
  77#define ADC_CH_CHG_I_MAX                1500
  78#define ADC_CH_BKBAT_MIN                0
  79#define ADC_CH_BKBAT_MAX                3200
  80
  81/* This is used to not lose precision when dividing to get gain and offset */
  82#define CALIB_SCALE                     1000
  83
  84enum cal_channels {
  85        ADC_INPUT_VMAIN = 0,
  86        ADC_INPUT_BTEMP,
  87        ADC_INPUT_VBAT,
  88        NBR_CAL_INPUTS,
  89};
  90
  91/**
  92 * struct adc_cal_data - Table for storing gain and offset for the calibrated
  93 * ADC channels
  94 * @gain:               Gain of the ADC channel
  95 * @offset:             Offset of the ADC channel
  96 */
  97struct adc_cal_data {
  98        u64 gain;
  99        u64 offset;
 100};
 101
 102/**
 103 * struct ab8500_gpadc - AB8500 GPADC device information
 104 * @dev:                        pointer to the struct device
 105 * @node:                       a list of AB8500 GPADCs, hence prepared for
 106                                reentrance
 107 * @ab8500_gpadc_complete:      pointer to the struct completion, to indicate
 108 *                              the completion of gpadc conversion
 109 * @ab8500_gpadc_lock:          structure of type mutex
 110 * @regu:                       pointer to the struct regulator
 111 * @irq:                        interrupt number that is used by gpadc
 112 * @cal_data                    array of ADC calibration data structs
 113 */
 114struct ab8500_gpadc {
 115        struct device *dev;
 116        struct list_head node;
 117        struct completion ab8500_gpadc_complete;
 118        struct mutex ab8500_gpadc_lock;
 119        struct regulator *regu;
 120        int irq;
 121        struct adc_cal_data cal_data[NBR_CAL_INPUTS];
 122};
 123
 124static LIST_HEAD(ab8500_gpadc_list);
 125
 126/**
 127 * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
 128 * (i.e. the first GPADC in the instance list)
 129 */
 130struct ab8500_gpadc *ab8500_gpadc_get(char *name)
 131{
 132        struct ab8500_gpadc *gpadc;
 133
 134        list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
 135                if (!strcmp(name, dev_name(gpadc->dev)))
 136                    return gpadc;
 137        }
 138
 139        return ERR_PTR(-ENOENT);
 140}
 141EXPORT_SYMBOL(ab8500_gpadc_get);
 142
 143static int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 input,
 144        int ad_value)
 145{
 146        int res;
 147
 148        switch (input) {
 149        case MAIN_CHARGER_V:
 150                /* For some reason we don't have calibrated data */
 151                if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) {
 152                        res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX -
 153                                ADC_CH_CHG_V_MIN) * ad_value /
 154                                ADC_RESOLUTION;
 155                        break;
 156                }
 157                /* Here we can use the calibrated data */
 158                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain +
 159                        gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE;
 160                break;
 161
 162        case BAT_CTRL:
 163        case BTEMP_BALL:
 164        case ACC_DETECT1:
 165        case ADC_AUX1:
 166        case ADC_AUX2:
 167                /* For some reason we don't have calibrated data */
 168                if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) {
 169                        res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX -
 170                                ADC_CH_BTEMP_MIN) * ad_value /
 171                                ADC_RESOLUTION;
 172                        break;
 173                }
 174                /* Here we can use the calibrated data */
 175                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain +
 176                        gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE;
 177                break;
 178
 179        case MAIN_BAT_V:
 180                /* For some reason we don't have calibrated data */
 181                if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) {
 182                        res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX -
 183                                ADC_CH_VBAT_MIN) * ad_value /
 184                                ADC_RESOLUTION;
 185                        break;
 186                }
 187                /* Here we can use the calibrated data */
 188                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain +
 189                        gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE;
 190                break;
 191
 192        case DIE_TEMP:
 193                res = ADC_CH_DIETEMP_MIN +
 194                        (ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value /
 195                        ADC_RESOLUTION;
 196                break;
 197
 198        case ACC_DETECT2:
 199                res = ADC_CH_ACCDET2_MIN +
 200                        (ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value /
 201                        ADC_RESOLUTION;
 202                break;
 203
 204        case VBUS_V:
 205                res = ADC_CH_CHG_V_MIN +
 206                        (ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value /
 207                        ADC_RESOLUTION;
 208                break;
 209
 210        case MAIN_CHARGER_C:
 211        case USB_CHARGER_C:
 212                res = ADC_CH_CHG_I_MIN +
 213                        (ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value /
 214                        ADC_RESOLUTION;
 215                break;
 216
 217        case BK_BAT_V:
 218                res = ADC_CH_BKBAT_MIN +
 219                        (ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value /
 220                        ADC_RESOLUTION;
 221                break;
 222
 223        default:
 224                dev_err(gpadc->dev,
 225                        "unknown channel, not possible to convert\n");
 226                res = -EINVAL;
 227                break;
 228
 229        }
 230        return res;
 231}
 232
 233/**
 234 * ab8500_gpadc_convert() - gpadc conversion
 235 * @input:      analog input to be converted to digital data
 236 *
 237 * This function converts the selected analog i/p to digital
 238 * data.
 239 */
 240int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
 241{
 242        int ret;
 243        u16 data = 0;
 244        int looplimit = 0;
 245        u8 val, low_data, high_data;
 246
 247        if (!gpadc)
 248                return -ENODEV;
 249
 250        mutex_lock(&gpadc->ab8500_gpadc_lock);
 251        /* Enable VTVout LDO this is required for GPADC */
 252        regulator_enable(gpadc->regu);
 253
 254        /* Check if ADC is not busy, lock and proceed */
 255        do {
 256                ret = abx500_get_register_interruptible(gpadc->dev,
 257                        AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
 258                if (ret < 0)
 259                        goto out;
 260                if (!(val & GPADC_BUSY))
 261                        break;
 262                msleep(10);
 263        } while (++looplimit < 10);
 264        if (looplimit >= 10 && (val & GPADC_BUSY)) {
 265                dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
 266                ret = -EINVAL;
 267                goto out;
 268        }
 269
 270        /* Enable GPADC */
 271        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 272                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
 273        if (ret < 0) {
 274                dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
 275                goto out;
 276        }
 277        /* Select the input source and set average samples to 16 */
 278        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 279                AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
 280        if (ret < 0) {
 281                dev_err(gpadc->dev,
 282                        "gpadc_conversion: set avg samples failed\n");
 283                goto out;
 284        }
 285        /*
 286         * Enable ADC, buffering, select rising edge and enable ADC path
 287         * charging current sense if it needed
 288         */
 289        switch (input) {
 290        case MAIN_CHARGER_C:
 291        case USB_CHARGER_C:
 292                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 293                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
 294                        EN_BUF | EN_ICHAR,
 295                        EN_BUF | EN_ICHAR);
 296                break;
 297        default:
 298                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 299                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
 300                break;
 301        }
 302        if (ret < 0) {
 303                dev_err(gpadc->dev,
 304                        "gpadc_conversion: select falling edge failed\n");
 305                goto out;
 306        }
 307        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 308                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
 309        if (ret < 0) {
 310                dev_err(gpadc->dev,
 311                        "gpadc_conversion: start s/w conversion failed\n");
 312                goto out;
 313        }
 314        /* wait for completion of conversion */
 315        if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {
 316                dev_err(gpadc->dev,
 317                        "timeout: didn't receive GPADC conversion interrupt\n");
 318                ret = -EINVAL;
 319                goto out;
 320        }
 321
 322        /* Read the converted RAW data */
 323        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 324                AB8500_GPADC_MANDATAL_REG, &low_data);
 325        if (ret < 0) {
 326                dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
 327                goto out;
 328        }
 329
 330        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 331                AB8500_GPADC_MANDATAH_REG, &high_data);
 332        if (ret < 0) {
 333                dev_err(gpadc->dev,
 334                        "gpadc_conversion: read high data failed\n");
 335                goto out;
 336        }
 337
 338        data = (high_data << 8) | low_data;
 339        /* Disable GPADC */
 340        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 341                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 342        if (ret < 0) {
 343                dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
 344                goto out;
 345        }
 346        /* Disable VTVout LDO this is required for GPADC */
 347        regulator_disable(gpadc->regu);
 348        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 349        ret = ab8500_gpadc_ad_to_voltage(gpadc, input, data);
 350        return ret;
 351
 352out:
 353        /*
 354         * It has shown to be needed to turn off the GPADC if an error occurs,
 355         * otherwise we might have problem when waiting for the busy bit in the
 356         * GPADC status register to go low. In V1.1 there wait_for_completion
 357         * seems to timeout when waiting for an interrupt.. Not seen in V2.0
 358         */
 359        (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 360                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 361        regulator_disable(gpadc->regu);
 362        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 363        dev_err(gpadc->dev,
 364                "gpadc_conversion: Failed to AD convert channel %d\n", input);
 365        return ret;
 366}
 367EXPORT_SYMBOL(ab8500_gpadc_convert);
 368
 369/**
 370 * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
 371 * @irq:        irq number
 372 * @data:       pointer to the data passed during request irq
 373 *
 374 * This is a interrupt service routine for s/w gpadc conversion completion.
 375 * Notifies the gpadc completion is completed and the converted raw value
 376 * can be read from the registers.
 377 * Returns IRQ status(IRQ_HANDLED)
 378 */
 379static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
 380{
 381        struct ab8500_gpadc *gpadc = _gpadc;
 382
 383        complete(&gpadc->ab8500_gpadc_complete);
 384
 385        return IRQ_HANDLED;
 386}
 387
 388static int otp_cal_regs[] = {
 389        AB8500_GPADC_CAL_1,
 390        AB8500_GPADC_CAL_2,
 391        AB8500_GPADC_CAL_3,
 392        AB8500_GPADC_CAL_4,
 393        AB8500_GPADC_CAL_5,
 394        AB8500_GPADC_CAL_6,
 395        AB8500_GPADC_CAL_7,
 396};
 397
 398static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
 399{
 400        int i;
 401        int ret[ARRAY_SIZE(otp_cal_regs)];
 402        u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];
 403
 404        int vmain_high, vmain_low;
 405        int btemp_high, btemp_low;
 406        int vbat_high, vbat_low;
 407
 408        /* First we read all OTP registers and store the error code */
 409        for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
 410                ret[i] = abx500_get_register_interruptible(gpadc->dev,
 411                        AB8500_OTP_EMUL, otp_cal_regs[i],  &gpadc_cal[i]);
 412                if (ret[i] < 0)
 413                        dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
 414                                __func__, otp_cal_regs[i]);
 415        }
 416
 417        /*
 418         * The ADC calibration data is stored in OTP registers.
 419         * The layout of the calibration data is outlined below and a more
 420         * detailed description can be found in UM0836
 421         *
 422         * vm_h/l = vmain_high/low
 423         * bt_h/l = btemp_high/low
 424         * vb_h/l = vbat_high/low
 425         *
 426         * Data bits:
 427         * | 7     | 6     | 5     | 4     | 3     | 2     | 1     | 0
 428         * |.......|.......|.......|.......|.......|.......|.......|.......
 429         * |                                               | vm_h9 | vm_h8
 430         * |.......|.......|.......|.......|.......|.......|.......|.......
 431         * |               | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
 432         * |.......|.......|.......|.......|.......|.......|.......|.......
 433         * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
 434         * |.......|.......|.......|.......|.......|.......|.......|.......
 435         * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
 436         * |.......|.......|.......|.......|.......|.......|.......|.......
 437         * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
 438         * |.......|.......|.......|.......|.......|.......|.......|.......
 439         * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
 440         * |.......|.......|.......|.......|.......|.......|.......|.......
 441         * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
 442         * |.......|.......|.......|.......|.......|.......|.......|.......
 443         *
 444         *
 445         * Ideal output ADC codes corresponding to injected input voltages
 446         * during manufacturing is:
 447         *
 448         * vmain_high: Vin = 19500mV / ADC ideal code = 997
 449         * vmain_low:  Vin = 315mV   / ADC ideal code = 16
 450         * btemp_high: Vin = 1300mV  / ADC ideal code = 985
 451         * btemp_low:  Vin = 21mV    / ADC ideal code = 16
 452         * vbat_high:  Vin = 4700mV  / ADC ideal code = 982
 453         * vbat_low:   Vin = 2380mV  / ADC ideal code = 33
 454         */
 455
 456        /* Calculate gain and offset for VMAIN if all reads succeeded */
 457        if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
 458                vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
 459                        ((gpadc_cal[1] & 0x3F) << 2) |
 460                        ((gpadc_cal[2] & 0xC0) >> 6));
 461
 462                vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);
 463
 464                gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE *
 465                        (19500 - 315) / (vmain_high - vmain_low);
 466
 467                gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 -
 468                        (CALIB_SCALE * (19500 - 315) /
 469                         (vmain_high - vmain_low)) * vmain_high;
 470        } else {
 471                gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0;
 472        }
 473
 474        /* Calculate gain and offset for BTEMP if all reads succeeded */
 475        if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
 476                btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
 477                        (gpadc_cal[3] << 1) |
 478                        ((gpadc_cal[4] & 0x80) >> 7));
 479
 480                btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);
 481
 482                gpadc->cal_data[ADC_INPUT_BTEMP].gain =
 483                        CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);
 484
 485                gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 -
 486                        (CALIB_SCALE * (1300 - 21) /
 487                        (btemp_high - btemp_low)) * btemp_high;
 488        } else {
 489                gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0;
 490        }
 491
 492        /* Calculate gain and offset for VBAT if all reads succeeded */
 493        if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
 494                vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
 495                vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);
 496
 497                gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE *
 498                        (4700 - 2380) / (vbat_high - vbat_low);
 499
 500                gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 -
 501                        (CALIB_SCALE * (4700 - 2380) /
 502                        (vbat_high - vbat_low)) * vbat_high;
 503        } else {
 504                gpadc->cal_data[ADC_INPUT_VBAT].gain = 0;
 505        }
 506
 507        dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n",
 508                gpadc->cal_data[ADC_INPUT_VMAIN].gain,
 509                gpadc->cal_data[ADC_INPUT_VMAIN].offset);
 510
 511        dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n",
 512                gpadc->cal_data[ADC_INPUT_BTEMP].gain,
 513                gpadc->cal_data[ADC_INPUT_BTEMP].offset);
 514
 515        dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n",
 516                gpadc->cal_data[ADC_INPUT_VBAT].gain,
 517                gpadc->cal_data[ADC_INPUT_VBAT].offset);
 518}
 519
 520static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
 521{
 522        int ret = 0;
 523        struct ab8500_gpadc *gpadc;
 524
 525        gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
 526        if (!gpadc) {
 527                dev_err(&pdev->dev, "Error: No memory\n");
 528                return -ENOMEM;
 529        }
 530
 531        gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
 532        if (gpadc->irq < 0) {
 533                dev_err(gpadc->dev, "failed to get platform irq-%d\n",
 534                        gpadc->irq);
 535                ret = gpadc->irq;
 536                goto fail;
 537        }
 538
 539        gpadc->dev = &pdev->dev;
 540        mutex_init(&gpadc->ab8500_gpadc_lock);
 541
 542        /* Initialize completion used to notify completion of conversion */
 543        init_completion(&gpadc->ab8500_gpadc_complete);
 544
 545        /* Register interrupt  - SwAdcComplete */
 546        ret = request_threaded_irq(gpadc->irq, NULL,
 547                ab8500_bm_gpswadcconvend_handler,
 548                IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
 549        if (ret < 0) {
 550                dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
 551                        gpadc->irq);
 552                goto fail;
 553        }
 554
 555        /* VTVout LDO used to power up ab8500-GPADC */
 556        gpadc->regu = regulator_get(&pdev->dev, "vddadc");
 557        if (IS_ERR(gpadc->regu)) {
 558                ret = PTR_ERR(gpadc->regu);
 559                dev_err(gpadc->dev, "failed to get vtvout LDO\n");
 560                goto fail_irq;
 561        }
 562        ab8500_gpadc_read_calibration_data(gpadc);
 563        list_add_tail(&gpadc->node, &ab8500_gpadc_list);
 564        dev_dbg(gpadc->dev, "probe success\n");
 565        return 0;
 566fail_irq:
 567        free_irq(gpadc->irq, gpadc);
 568fail:
 569        kfree(gpadc);
 570        gpadc = NULL;
 571        return ret;
 572}
 573
 574static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
 575{
 576        struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
 577
 578        /* remove this gpadc entry from the list */
 579        list_del(&gpadc->node);
 580        /* remove interrupt  - completion of Sw ADC conversion */
 581        free_irq(gpadc->irq, gpadc);
 582        /* disable VTVout LDO that is being used by GPADC */
 583        regulator_put(gpadc->regu);
 584        kfree(gpadc);
 585        gpadc = NULL;
 586        return 0;
 587}
 588
 589static struct platform_driver ab8500_gpadc_driver = {
 590        .probe = ab8500_gpadc_probe,
 591        .remove = __devexit_p(ab8500_gpadc_remove),
 592        .driver = {
 593                .name = "ab8500-gpadc",
 594                .owner = THIS_MODULE,
 595        },
 596};
 597
 598static int __init ab8500_gpadc_init(void)
 599{
 600        return platform_driver_register(&ab8500_gpadc_driver);
 601}
 602
 603static void __exit ab8500_gpadc_exit(void)
 604{
 605        platform_driver_unregister(&ab8500_gpadc_driver);
 606}
 607
 608subsys_initcall_sync(ab8500_gpadc_init);
 609module_exit(ab8500_gpadc_exit);
 610
 611MODULE_LICENSE("GPL v2");
 612MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
 613MODULE_ALIAS("platform:ab8500_gpadc");
 614MODULE_DESCRIPTION("AB8500 GPADC driver");
 615