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/abx500.h>
  22#include <linux/mfd/abx500/ab8500.h>
  23#include <linux/mfd/abx500/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 BTEMP_PULL_UP                   0x08
  61#define EN_BUF                          0x40
  62#define DIS_ZERO                        0x00
  63#define GPADC_BUSY                      0x01
  64
  65/* GPADC constants from AB8500 spec, UM0836 */
  66#define ADC_RESOLUTION                  1024
  67#define ADC_CH_BTEMP_MIN                0
  68#define ADC_CH_BTEMP_MAX                1350
  69#define ADC_CH_DIETEMP_MIN              0
  70#define ADC_CH_DIETEMP_MAX              1350
  71#define ADC_CH_CHG_V_MIN                0
  72#define ADC_CH_CHG_V_MAX                20030
  73#define ADC_CH_ACCDET2_MIN              0
  74#define ADC_CH_ACCDET2_MAX              2500
  75#define ADC_CH_VBAT_MIN                 2300
  76#define ADC_CH_VBAT_MAX                 4800
  77#define ADC_CH_CHG_I_MIN                0
  78#define ADC_CH_CHG_I_MAX                1500
  79#define ADC_CH_BKBAT_MIN                0
  80#define ADC_CH_BKBAT_MAX                3200
  81
  82/* This is used to not lose precision when dividing to get gain and offset */
  83#define CALIB_SCALE                     1000
  84
  85enum cal_channels {
  86        ADC_INPUT_VMAIN = 0,
  87        ADC_INPUT_BTEMP,
  88        ADC_INPUT_VBAT,
  89        NBR_CAL_INPUTS,
  90};
  91
  92/**
  93 * struct adc_cal_data - Table for storing gain and offset for the calibrated
  94 * ADC channels
  95 * @gain:               Gain of the ADC channel
  96 * @offset:             Offset of the ADC channel
  97 */
  98struct adc_cal_data {
  99        u64 gain;
 100        u64 offset;
 101};
 102
 103/**
 104 * struct ab8500_gpadc - AB8500 GPADC device information
 105 * @chip_id                     ABB chip id
 106 * @dev:                        pointer to the struct device
 107 * @node:                       a list of AB8500 GPADCs, hence prepared for
 108                                reentrance
 109 * @ab8500_gpadc_complete:      pointer to the struct completion, to indicate
 110 *                              the completion of gpadc conversion
 111 * @ab8500_gpadc_lock:          structure of type mutex
 112 * @regu:                       pointer to the struct regulator
 113 * @irq:                        interrupt number that is used by gpadc
 114 * @cal_data                    array of ADC calibration data structs
 115 */
 116struct ab8500_gpadc {
 117        u8 chip_id;
 118        struct device *dev;
 119        struct list_head node;
 120        struct completion ab8500_gpadc_complete;
 121        struct mutex ab8500_gpadc_lock;
 122        struct regulator *regu;
 123        int irq;
 124        struct adc_cal_data cal_data[NBR_CAL_INPUTS];
 125};
 126
 127static LIST_HEAD(ab8500_gpadc_list);
 128
 129/**
 130 * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
 131 * (i.e. the first GPADC in the instance list)
 132 */
 133struct ab8500_gpadc *ab8500_gpadc_get(char *name)
 134{
 135        struct ab8500_gpadc *gpadc;
 136
 137        list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
 138                if (!strcmp(name, dev_name(gpadc->dev)))
 139                    return gpadc;
 140        }
 141
 142        return ERR_PTR(-ENOENT);
 143}
 144EXPORT_SYMBOL(ab8500_gpadc_get);
 145
 146/**
 147 * ab8500_gpadc_ad_to_voltage() - Convert a raw ADC value to a voltage
 148 */
 149int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 channel,
 150        int ad_value)
 151{
 152        int res;
 153
 154        switch (channel) {
 155        case MAIN_CHARGER_V:
 156                /* For some reason we don't have calibrated data */
 157                if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) {
 158                        res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX -
 159                                ADC_CH_CHG_V_MIN) * ad_value /
 160                                ADC_RESOLUTION;
 161                        break;
 162                }
 163                /* Here we can use the calibrated data */
 164                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain +
 165                        gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE;
 166                break;
 167
 168        case BAT_CTRL:
 169        case BTEMP_BALL:
 170        case ACC_DETECT1:
 171        case ADC_AUX1:
 172        case ADC_AUX2:
 173                /* For some reason we don't have calibrated data */
 174                if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) {
 175                        res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX -
 176                                ADC_CH_BTEMP_MIN) * ad_value /
 177                                ADC_RESOLUTION;
 178                        break;
 179                }
 180                /* Here we can use the calibrated data */
 181                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain +
 182                        gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE;
 183                break;
 184
 185        case MAIN_BAT_V:
 186                /* For some reason we don't have calibrated data */
 187                if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) {
 188                        res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX -
 189                                ADC_CH_VBAT_MIN) * ad_value /
 190                                ADC_RESOLUTION;
 191                        break;
 192                }
 193                /* Here we can use the calibrated data */
 194                res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain +
 195                        gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE;
 196                break;
 197
 198        case DIE_TEMP:
 199                res = ADC_CH_DIETEMP_MIN +
 200                        (ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value /
 201                        ADC_RESOLUTION;
 202                break;
 203
 204        case ACC_DETECT2:
 205                res = ADC_CH_ACCDET2_MIN +
 206                        (ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value /
 207                        ADC_RESOLUTION;
 208                break;
 209
 210        case VBUS_V:
 211                res = ADC_CH_CHG_V_MIN +
 212                        (ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value /
 213                        ADC_RESOLUTION;
 214                break;
 215
 216        case MAIN_CHARGER_C:
 217        case USB_CHARGER_C:
 218                res = ADC_CH_CHG_I_MIN +
 219                        (ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value /
 220                        ADC_RESOLUTION;
 221                break;
 222
 223        case BK_BAT_V:
 224                res = ADC_CH_BKBAT_MIN +
 225                        (ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value /
 226                        ADC_RESOLUTION;
 227                break;
 228
 229        default:
 230                dev_err(gpadc->dev,
 231                        "unknown channel, not possible to convert\n");
 232                res = -EINVAL;
 233                break;
 234
 235        }
 236        return res;
 237}
 238EXPORT_SYMBOL(ab8500_gpadc_ad_to_voltage);
 239
 240/**
 241 * ab8500_gpadc_convert() - gpadc conversion
 242 * @channel:    analog channel to be converted to digital data
 243 *
 244 * This function converts the selected analog i/p to digital
 245 * data.
 246 */
 247int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 channel)
 248{
 249        int ad_value;
 250        int voltage;
 251
 252        ad_value = ab8500_gpadc_read_raw(gpadc, channel);
 253        if (ad_value < 0) {
 254                dev_err(gpadc->dev, "GPADC raw value failed ch: %d\n", channel);
 255                return ad_value;
 256        }
 257
 258        voltage = ab8500_gpadc_ad_to_voltage(gpadc, channel, ad_value);
 259
 260        if (voltage < 0)
 261                dev_err(gpadc->dev, "GPADC to voltage conversion failed ch:"
 262                        " %d AD: 0x%x\n", channel, ad_value);
 263
 264        return voltage;
 265}
 266EXPORT_SYMBOL(ab8500_gpadc_convert);
 267
 268/**
 269 * ab8500_gpadc_read_raw() - gpadc read
 270 * @channel:    analog channel to be read
 271 *
 272 * This function obtains the raw ADC value, this then needs
 273 * to be converted by calling ab8500_gpadc_ad_to_voltage()
 274 */
 275int ab8500_gpadc_read_raw(struct ab8500_gpadc *gpadc, u8 channel)
 276{
 277        int ret;
 278        int looplimit = 0;
 279        u8 val, low_data, high_data;
 280
 281        if (!gpadc)
 282                return -ENODEV;
 283
 284        mutex_lock(&gpadc->ab8500_gpadc_lock);
 285        /* Enable VTVout LDO this is required for GPADC */
 286        regulator_enable(gpadc->regu);
 287
 288        /* Check if ADC is not busy, lock and proceed */
 289        do {
 290                ret = abx500_get_register_interruptible(gpadc->dev,
 291                        AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
 292                if (ret < 0)
 293                        goto out;
 294                if (!(val & GPADC_BUSY))
 295                        break;
 296                msleep(10);
 297        } while (++looplimit < 10);
 298        if (looplimit >= 10 && (val & GPADC_BUSY)) {
 299                dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
 300                ret = -EINVAL;
 301                goto out;
 302        }
 303
 304        /* Enable GPADC */
 305        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 306                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
 307        if (ret < 0) {
 308                dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
 309                goto out;
 310        }
 311
 312        /* Select the channel source and set average samples to 16 */
 313        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 314                AB8500_GPADC_CTRL2_REG, (channel | SW_AVG_16));
 315        if (ret < 0) {
 316                dev_err(gpadc->dev,
 317                        "gpadc_conversion: set avg samples failed\n");
 318                goto out;
 319        }
 320
 321        /*
 322         * Enable ADC, buffering, select rising edge and enable ADC path
 323         * charging current sense if it needed, ABB 3.0 needs some special
 324         * treatment too.
 325         */
 326        switch (channel) {
 327        case MAIN_CHARGER_C:
 328        case USB_CHARGER_C:
 329                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 330                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
 331                        EN_BUF | EN_ICHAR,
 332                        EN_BUF | EN_ICHAR);
 333                break;
 334        case BTEMP_BALL:
 335                if (gpadc->chip_id >= AB8500_CUT3P0) {
 336                        /* Turn on btemp pull-up on ABB 3.0 */
 337                        ret = abx500_mask_and_set_register_interruptible(
 338                                gpadc->dev,
 339                                AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
 340                                EN_BUF | BTEMP_PULL_UP,
 341                                EN_BUF | BTEMP_PULL_UP);
 342
 343                 /*
 344                  * Delay might be needed for ABB8500 cut 3.0, if not, remove
 345                  * when hardware will be available
 346                  */
 347                        msleep(1);
 348                        break;
 349                }
 350                /* Intentional fallthrough */
 351        default:
 352                ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 353                        AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
 354                break;
 355        }
 356        if (ret < 0) {
 357                dev_err(gpadc->dev,
 358                        "gpadc_conversion: select falling edge failed\n");
 359                goto out;
 360        }
 361
 362        ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
 363                AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
 364        if (ret < 0) {
 365                dev_err(gpadc->dev,
 366                        "gpadc_conversion: start s/w conversion failed\n");
 367                goto out;
 368        }
 369        /* wait for completion of conversion */
 370        if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {
 371                dev_err(gpadc->dev,
 372                        "timeout: didn't receive GPADC conversion interrupt\n");
 373                ret = -EINVAL;
 374                goto out;
 375        }
 376
 377        /* Read the converted RAW data */
 378        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 379                AB8500_GPADC_MANDATAL_REG, &low_data);
 380        if (ret < 0) {
 381                dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
 382                goto out;
 383        }
 384
 385        ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
 386                AB8500_GPADC_MANDATAH_REG, &high_data);
 387        if (ret < 0) {
 388                dev_err(gpadc->dev,
 389                        "gpadc_conversion: read high data failed\n");
 390                goto out;
 391        }
 392
 393        /* Disable GPADC */
 394        ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 395                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 396        if (ret < 0) {
 397                dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
 398                goto out;
 399        }
 400        /* Disable VTVout LDO this is required for GPADC */
 401        regulator_disable(gpadc->regu);
 402        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 403
 404        return (high_data << 8) | low_data;
 405
 406out:
 407        /*
 408         * It has shown to be needed to turn off the GPADC if an error occurs,
 409         * otherwise we might have problem when waiting for the busy bit in the
 410         * GPADC status register to go low. In V1.1 there wait_for_completion
 411         * seems to timeout when waiting for an interrupt.. Not seen in V2.0
 412         */
 413        (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
 414                AB8500_GPADC_CTRL1_REG, DIS_GPADC);
 415        regulator_disable(gpadc->regu);
 416        mutex_unlock(&gpadc->ab8500_gpadc_lock);
 417        dev_err(gpadc->dev,
 418                "gpadc_conversion: Failed to AD convert channel %d\n", channel);
 419        return ret;
 420}
 421EXPORT_SYMBOL(ab8500_gpadc_read_raw);
 422
 423/**
 424 * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
 425 * @irq:        irq number
 426 * @data:       pointer to the data passed during request irq
 427 *
 428 * This is a interrupt service routine for s/w gpadc conversion completion.
 429 * Notifies the gpadc completion is completed and the converted raw value
 430 * can be read from the registers.
 431 * Returns IRQ status(IRQ_HANDLED)
 432 */
 433static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
 434{
 435        struct ab8500_gpadc *gpadc = _gpadc;
 436
 437        complete(&gpadc->ab8500_gpadc_complete);
 438
 439        return IRQ_HANDLED;
 440}
 441
 442static int otp_cal_regs[] = {
 443        AB8500_GPADC_CAL_1,
 444        AB8500_GPADC_CAL_2,
 445        AB8500_GPADC_CAL_3,
 446        AB8500_GPADC_CAL_4,
 447        AB8500_GPADC_CAL_5,
 448        AB8500_GPADC_CAL_6,
 449        AB8500_GPADC_CAL_7,
 450};
 451
 452static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
 453{
 454        int i;
 455        int ret[ARRAY_SIZE(otp_cal_regs)];
 456        u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];
 457
 458        int vmain_high, vmain_low;
 459        int btemp_high, btemp_low;
 460        int vbat_high, vbat_low;
 461
 462        /* First we read all OTP registers and store the error code */
 463        for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
 464                ret[i] = abx500_get_register_interruptible(gpadc->dev,
 465                        AB8500_OTP_EMUL, otp_cal_regs[i],  &gpadc_cal[i]);
 466                if (ret[i] < 0)
 467                        dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
 468                                __func__, otp_cal_regs[i]);
 469        }
 470
 471        /*
 472         * The ADC calibration data is stored in OTP registers.
 473         * The layout of the calibration data is outlined below and a more
 474         * detailed description can be found in UM0836
 475         *
 476         * vm_h/l = vmain_high/low
 477         * bt_h/l = btemp_high/low
 478         * vb_h/l = vbat_high/low
 479         *
 480         * Data bits:
 481         * | 7     | 6     | 5     | 4     | 3     | 2     | 1     | 0
 482         * |.......|.......|.......|.......|.......|.......|.......|.......
 483         * |                                               | vm_h9 | vm_h8
 484         * |.......|.......|.......|.......|.......|.......|.......|.......
 485         * |               | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
 486         * |.......|.......|.......|.......|.......|.......|.......|.......
 487         * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
 488         * |.......|.......|.......|.......|.......|.......|.......|.......
 489         * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
 490         * |.......|.......|.......|.......|.......|.......|.......|.......
 491         * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
 492         * |.......|.......|.......|.......|.......|.......|.......|.......
 493         * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
 494         * |.......|.......|.......|.......|.......|.......|.......|.......
 495         * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
 496         * |.......|.......|.......|.......|.......|.......|.......|.......
 497         *
 498         *
 499         * Ideal output ADC codes corresponding to injected input voltages
 500         * during manufacturing is:
 501         *
 502         * vmain_high: Vin = 19500mV / ADC ideal code = 997
 503         * vmain_low:  Vin = 315mV   / ADC ideal code = 16
 504         * btemp_high: Vin = 1300mV  / ADC ideal code = 985
 505         * btemp_low:  Vin = 21mV    / ADC ideal code = 16
 506         * vbat_high:  Vin = 4700mV  / ADC ideal code = 982
 507         * vbat_low:   Vin = 2380mV  / ADC ideal code = 33
 508         */
 509
 510        /* Calculate gain and offset for VMAIN if all reads succeeded */
 511        if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
 512                vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
 513                        ((gpadc_cal[1] & 0x3F) << 2) |
 514                        ((gpadc_cal[2] & 0xC0) >> 6));
 515
 516                vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);
 517
 518                gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE *
 519                        (19500 - 315) / (vmain_high - vmain_low);
 520
 521                gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 -
 522                        (CALIB_SCALE * (19500 - 315) /
 523                         (vmain_high - vmain_low)) * vmain_high;
 524        } else {
 525                gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0;
 526        }
 527
 528        /* Calculate gain and offset for BTEMP if all reads succeeded */
 529        if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
 530                btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
 531                        (gpadc_cal[3] << 1) |
 532                        ((gpadc_cal[4] & 0x80) >> 7));
 533
 534                btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);
 535
 536                gpadc->cal_data[ADC_INPUT_BTEMP].gain =
 537                        CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);
 538
 539                gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 -
 540                        (CALIB_SCALE * (1300 - 21) /
 541                        (btemp_high - btemp_low)) * btemp_high;
 542        } else {
 543                gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0;
 544        }
 545
 546        /* Calculate gain and offset for VBAT if all reads succeeded */
 547        if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
 548                vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
 549                vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);
 550
 551                gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE *
 552                        (4700 - 2380) / (vbat_high - vbat_low);
 553
 554                gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 -
 555                        (CALIB_SCALE * (4700 - 2380) /
 556                        (vbat_high - vbat_low)) * vbat_high;
 557        } else {
 558                gpadc->cal_data[ADC_INPUT_VBAT].gain = 0;
 559        }
 560
 561        dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n",
 562                gpadc->cal_data[ADC_INPUT_VMAIN].gain,
 563                gpadc->cal_data[ADC_INPUT_VMAIN].offset);
 564
 565        dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n",
 566                gpadc->cal_data[ADC_INPUT_BTEMP].gain,
 567                gpadc->cal_data[ADC_INPUT_BTEMP].offset);
 568
 569        dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n",
 570                gpadc->cal_data[ADC_INPUT_VBAT].gain,
 571                gpadc->cal_data[ADC_INPUT_VBAT].offset);
 572}
 573
 574static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
 575{
 576        int ret = 0;
 577        struct ab8500_gpadc *gpadc;
 578
 579        gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
 580        if (!gpadc) {
 581                dev_err(&pdev->dev, "Error: No memory\n");
 582                return -ENOMEM;
 583        }
 584
 585        gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
 586        if (gpadc->irq < 0) {
 587                dev_err(&pdev->dev, "failed to get platform irq-%d\n",
 588                        gpadc->irq);
 589                ret = gpadc->irq;
 590                goto fail;
 591        }
 592
 593        gpadc->dev = &pdev->dev;
 594        mutex_init(&gpadc->ab8500_gpadc_lock);
 595
 596        /* Initialize completion used to notify completion of conversion */
 597        init_completion(&gpadc->ab8500_gpadc_complete);
 598
 599        /* Register interrupt  - SwAdcComplete */
 600        ret = request_threaded_irq(gpadc->irq, NULL,
 601                ab8500_bm_gpswadcconvend_handler,
 602                IRQF_ONESHOT | IRQF_NO_SUSPEND | IRQF_SHARED,
 603                                "ab8500-gpadc", gpadc);
 604        if (ret < 0) {
 605                dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
 606                        gpadc->irq);
 607                goto fail;
 608        }
 609
 610        /* Get Chip ID of the ABB ASIC  */
 611        ret = abx500_get_chip_id(gpadc->dev);
 612        if (ret < 0) {
 613                dev_err(gpadc->dev, "failed to get chip ID\n");
 614                goto fail_irq;
 615        }
 616        gpadc->chip_id = (u8) ret;
 617
 618        /* VTVout LDO used to power up ab8500-GPADC */
 619        gpadc->regu = regulator_get(&pdev->dev, "vddadc");
 620        if (IS_ERR(gpadc->regu)) {
 621                ret = PTR_ERR(gpadc->regu);
 622                dev_err(gpadc->dev, "failed to get vtvout LDO\n");
 623                goto fail_irq;
 624        }
 625        ab8500_gpadc_read_calibration_data(gpadc);
 626        list_add_tail(&gpadc->node, &ab8500_gpadc_list);
 627        dev_dbg(gpadc->dev, "probe success\n");
 628        return 0;
 629fail_irq:
 630        free_irq(gpadc->irq, gpadc);
 631fail:
 632        kfree(gpadc);
 633        gpadc = NULL;
 634        return ret;
 635}
 636
 637static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
 638{
 639        struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
 640
 641        /* remove this gpadc entry from the list */
 642        list_del(&gpadc->node);
 643        /* remove interrupt  - completion of Sw ADC conversion */
 644        free_irq(gpadc->irq, gpadc);
 645        /* disable VTVout LDO that is being used by GPADC */
 646        regulator_put(gpadc->regu);
 647        kfree(gpadc);
 648        gpadc = NULL;
 649        return 0;
 650}
 651
 652static struct platform_driver ab8500_gpadc_driver = {
 653        .probe = ab8500_gpadc_probe,
 654        .remove = __devexit_p(ab8500_gpadc_remove),
 655        .driver = {
 656                .name = "ab8500-gpadc",
 657                .owner = THIS_MODULE,
 658        },
 659};
 660
 661static int __init ab8500_gpadc_init(void)
 662{
 663        return platform_driver_register(&ab8500_gpadc_driver);
 664}
 665
 666static void __exit ab8500_gpadc_exit(void)
 667{
 668        platform_driver_unregister(&ab8500_gpadc_driver);
 669}
 670
 671subsys_initcall_sync(ab8500_gpadc_init);
 672module_exit(ab8500_gpadc_exit);
 673
 674MODULE_LICENSE("GPL v2");
 675MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
 676MODULE_ALIAS("platform:ab8500_gpadc");
 677MODULE_DESCRIPTION("AB8500 GPADC driver");
 678