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
  85 enum 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  */
  98 struct 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  */
 116 struct 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
 127 static 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  */
 133 struct 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 }
 144 EXPORT_SYMBOL(ab8500_gpadc_get);
 145
 146 /**
 147  * ab8500_gpadc_ad_to_voltage() - Convert a raw ADC value to a voltage
 148  */
 149 int 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 }
 238 EXPORT_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  */
 247 int 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 }
 266 EXPORT_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  */
 275 int 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
 406 out:
 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 }
 421 EXPORT_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  */
 433 static 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
 442 static 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
 452 static 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
 574 static 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;
 629 fail_irq:
 630         free_irq(gpadc->irq, gpadc);
 631 fail:
 632         kfree(gpadc);
 633         gpadc = NULL;
 634         return ret;
 635 }
 636
 637 static 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
 652 static 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
 661 static int __init ab8500_gpadc_init(void)
 662 {
 663         return platform_driver_register(&ab8500_gpadc_driver);
 664 }
 665
 666 static void __exit ab8500_gpadc_exit(void)
 667 {
 668         platform_driver_unregister(&ab8500_gpadc_driver);
 669 }
 670
 671 subsys_initcall_sync(ab8500_gpadc_init);
 672 module_exit(ab8500_gpadc_exit);
 673
 674 MODULE_LICENSE("GPL v2");
 675 MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
 676 MODULE_ALIAS("platform:ab8500_gpadc");
 677 MODULE_DESCRIPTION("AB8500 GPADC driver");