linux/drivers/power/ds2760_battery.c
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   1/*
   2 * Driver for batteries with DS2760 chips inside.
   3 *
   4 * Copyright © 2007 Anton Vorontsov
   5 *             2004-2007 Matt Reimer
   6 *             2004 Szabolcs Gyurko
   7 *
   8 * Use consistent with the GNU GPL is permitted,
   9 * provided that this copyright notice is
  10 * preserved in its entirety in all copies and derived works.
  11 *
  12 * Author:  Anton Vorontsov <cbou@mail.ru>
  13 *          February 2007
  14 *
  15 *          Matt Reimer <mreimer@vpop.net>
  16 *          April 2004, 2005, 2007
  17 *
  18 *          Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
  19 *          September 2004
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/param.h>
  24#include <linux/jiffies.h>
  25#include <linux/workqueue.h>
  26#include <linux/pm.h>
  27#include <linux/slab.h>
  28#include <linux/platform_device.h>
  29#include <linux/power_supply.h>
  30
  31#include "../w1/w1.h"
  32#include "../w1/slaves/w1_ds2760.h"
  33
  34struct ds2760_device_info {
  35        struct device *dev;
  36
  37        /* DS2760 data, valid after calling ds2760_battery_read_status() */
  38        unsigned long update_time;      /* jiffies when data read */
  39        char raw[DS2760_DATA_SIZE];     /* raw DS2760 data */
  40        int voltage_raw;                /* units of 4.88 mV */
  41        int voltage_uV;                 /* units of µV */
  42        int current_raw;                /* units of 0.625 mA */
  43        int current_uA;                 /* units of µA */
  44        int accum_current_raw;          /* units of 0.25 mAh */
  45        int accum_current_uAh;          /* units of µAh */
  46        int temp_raw;                   /* units of 0.125 °C */
  47        int temp_C;                     /* units of 0.1 °C */
  48        int rated_capacity;             /* units of µAh */
  49        int rem_capacity;               /* percentage */
  50        int full_active_uAh;            /* units of µAh */
  51        int empty_uAh;                  /* units of µAh */
  52        int life_sec;                   /* units of seconds */
  53        int charge_status;              /* POWER_SUPPLY_STATUS_* */
  54
  55        int full_counter;
  56        struct power_supply bat;
  57        struct device *w1_dev;
  58        struct workqueue_struct *monitor_wqueue;
  59        struct delayed_work monitor_work;
  60        struct delayed_work set_charged_work;
  61};
  62
  63static unsigned int cache_time = 1000;
  64module_param(cache_time, uint, 0644);
  65MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  66
  67static bool pmod_enabled;
  68module_param(pmod_enabled, bool, 0644);
  69MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
  70
  71static unsigned int rated_capacity;
  72module_param(rated_capacity, uint, 0644);
  73MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
  74
  75static unsigned int current_accum;
  76module_param(current_accum, uint, 0644);
  77MODULE_PARM_DESC(current_accum, "current accumulator value");
  78
  79/* Some batteries have their rated capacity stored a N * 10 mAh, while
  80 * others use an index into this table. */
  81static int rated_capacities[] = {
  82        0,
  83        920,    /* Samsung */
  84        920,    /* BYD */
  85        920,    /* Lishen */
  86        920,    /* NEC */
  87        1440,   /* Samsung */
  88        1440,   /* BYD */
  89#ifdef CONFIG_MACH_H4700
  90        1800,   /* HP iPAQ hx4700 3.7V 1800mAh (359113-001) */
  91#else
  92        1440,   /* Lishen */
  93#endif
  94        1440,   /* NEC */
  95        2880,   /* Samsung */
  96        2880,   /* BYD */
  97        2880,   /* Lishen */
  98        2880,   /* NEC */
  99#ifdef CONFIG_MACH_H4700
 100        0,
 101        3600,   /* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
 102#endif
 103};
 104
 105/* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
 106 * temp is in Celsius */
 107static int battery_interpolate(int array[], int temp)
 108{
 109        int index, dt;
 110
 111        if (temp <= 0)
 112                return array[0];
 113        if (temp >= 40)
 114                return array[4];
 115
 116        index = temp / 10;
 117        dt    = temp % 10;
 118
 119        return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
 120}
 121
 122static int ds2760_battery_read_status(struct ds2760_device_info *di)
 123{
 124        int ret, i, start, count, scale[5];
 125
 126        if (di->update_time && time_before(jiffies, di->update_time +
 127                                           msecs_to_jiffies(cache_time)))
 128                return 0;
 129
 130        /* The first time we read the entire contents of SRAM/EEPROM,
 131         * but after that we just read the interesting bits that change. */
 132        if (di->update_time == 0) {
 133                start = 0;
 134                count = DS2760_DATA_SIZE;
 135        } else {
 136                start = DS2760_VOLTAGE_MSB;
 137                count = DS2760_TEMP_LSB - start + 1;
 138        }
 139
 140        ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
 141        if (ret != count) {
 142                dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
 143                         di->w1_dev);
 144                return 1;
 145        }
 146
 147        di->update_time = jiffies;
 148
 149        /* DS2760 reports voltage in units of 4.88mV, but the battery class
 150         * reports in units of uV, so convert by multiplying by 4880. */
 151        di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
 152                          (di->raw[DS2760_VOLTAGE_LSB] >> 5);
 153        di->voltage_uV = di->voltage_raw * 4880;
 154
 155        /* DS2760 reports current in signed units of 0.625mA, but the battery
 156         * class reports in units of µA, so convert by multiplying by 625. */
 157        di->current_raw =
 158            (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
 159                          (di->raw[DS2760_CURRENT_LSB] >> 3);
 160        di->current_uA = di->current_raw * 625;
 161
 162        /* DS2760 reports accumulated current in signed units of 0.25mAh. */
 163        di->accum_current_raw =
 164            (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
 165                           di->raw[DS2760_CURRENT_ACCUM_LSB];
 166        di->accum_current_uAh = di->accum_current_raw * 250;
 167
 168        /* DS2760 reports temperature in signed units of 0.125°C, but the
 169         * battery class reports in units of 1/10 °C, so we convert by
 170         * multiplying by .125 * 10 = 1.25. */
 171        di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
 172                                     (di->raw[DS2760_TEMP_LSB] >> 5);
 173        di->temp_C = di->temp_raw + (di->temp_raw / 4);
 174
 175        /* At least some battery monitors (e.g. HP iPAQ) store the battery's
 176         * maximum rated capacity. */
 177        if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
 178                di->rated_capacity = rated_capacities[
 179                        (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
 180        else
 181                di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
 182
 183        di->rated_capacity *= 1000; /* convert to µAh */
 184
 185        /* Calculate the full level at the present temperature. */
 186        di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
 187                              di->raw[DS2760_ACTIVE_FULL + 1];
 188
 189        /* If the full_active_uAh value is not given, fall back to the rated
 190         * capacity. This is likely to happen when chips are not part of the
 191         * battery pack and is therefore not bootstrapped. */
 192        if (di->full_active_uAh == 0)
 193                di->full_active_uAh = di->rated_capacity / 1000L;
 194
 195        scale[0] = di->full_active_uAh;
 196        for (i = 1; i < 5; i++)
 197                scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
 198
 199        di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
 200        di->full_active_uAh *= 1000; /* convert to µAh */
 201
 202        /* Calculate the empty level at the present temperature. */
 203        scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
 204        for (i = 3; i >= 0; i--)
 205                scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
 206
 207        di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
 208        di->empty_uAh *= 1000; /* convert to µAh */
 209
 210        if (di->full_active_uAh == di->empty_uAh)
 211                di->rem_capacity = 0;
 212        else
 213                /* From Maxim Application Note 131: remaining capacity =
 214                 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
 215                di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
 216                                    (di->full_active_uAh - di->empty_uAh);
 217
 218        if (di->rem_capacity < 0)
 219                di->rem_capacity = 0;
 220        if (di->rem_capacity > 100)
 221                di->rem_capacity = 100;
 222
 223        if (di->current_uA < -100L)
 224                di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
 225                                        / (di->current_uA / 100L);
 226        else
 227                di->life_sec = 0;
 228
 229        return 0;
 230}
 231
 232static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
 233                                             unsigned int acr_val)
 234{
 235        unsigned char acr[2];
 236
 237        /* acr is in units of 0.25 mAh */
 238        acr_val *= 4L;
 239        acr_val /= 1000;
 240
 241        acr[0] = acr_val >> 8;
 242        acr[1] = acr_val & 0xff;
 243
 244        if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
 245                dev_warn(di->dev, "ACR write failed\n");
 246}
 247
 248static void ds2760_battery_update_status(struct ds2760_device_info *di)
 249{
 250        int old_charge_status = di->charge_status;
 251
 252        ds2760_battery_read_status(di);
 253
 254        if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
 255                di->full_counter = 0;
 256
 257        if (power_supply_am_i_supplied(&di->bat)) {
 258                if (di->current_uA > 10000) {
 259                        di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
 260                        di->full_counter = 0;
 261                } else if (di->current_uA < -5000) {
 262                        if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
 263                                dev_notice(di->dev, "not enough power to "
 264                                           "charge\n");
 265                        di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 266                        di->full_counter = 0;
 267                } else if (di->current_uA < 10000 &&
 268                            di->charge_status != POWER_SUPPLY_STATUS_FULL) {
 269
 270                        /* Don't consider the battery to be full unless
 271                         * we've seen the current < 10 mA at least two
 272                         * consecutive times. */
 273
 274                        di->full_counter++;
 275
 276                        if (di->full_counter < 2) {
 277                                di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
 278                        } else {
 279                                di->charge_status = POWER_SUPPLY_STATUS_FULL;
 280                                ds2760_battery_set_current_accum(di,
 281                                                di->full_active_uAh);
 282                        }
 283                }
 284        } else {
 285                di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
 286                di->full_counter = 0;
 287        }
 288
 289        if (di->charge_status != old_charge_status)
 290                power_supply_changed(&di->bat);
 291}
 292
 293static void ds2760_battery_write_status(struct ds2760_device_info *di,
 294                                        char status)
 295{
 296        if (status == di->raw[DS2760_STATUS_REG])
 297                return;
 298
 299        w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
 300        w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 301        w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 302}
 303
 304static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
 305                                                unsigned char rated_capacity)
 306{
 307        if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
 308                return;
 309
 310        w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
 311        w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 312        w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 313}
 314
 315static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
 316                                             int active_full)
 317{
 318        unsigned char tmp[2] = {
 319                active_full >> 8,
 320                active_full & 0xff
 321        };
 322
 323        if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
 324            tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
 325                return;
 326
 327        w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
 328        w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
 329        w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
 330
 331        /* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
 332         * values won't be read back by ds2760_battery_read_status() */
 333        di->raw[DS2760_ACTIVE_FULL] = tmp[0];
 334        di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
 335}
 336
 337static void ds2760_battery_work(struct work_struct *work)
 338{
 339        struct ds2760_device_info *di = container_of(work,
 340                struct ds2760_device_info, monitor_work.work);
 341        const int interval = HZ * 60;
 342
 343        dev_dbg(di->dev, "%s\n", __func__);
 344
 345        ds2760_battery_update_status(di);
 346        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
 347}
 348
 349#define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
 350                                              bat);
 351
 352static void ds2760_battery_external_power_changed(struct power_supply *psy)
 353{
 354        struct ds2760_device_info *di = to_ds2760_device_info(psy);
 355
 356        dev_dbg(di->dev, "%s\n", __func__);
 357
 358        cancel_delayed_work(&di->monitor_work);
 359        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
 360}
 361
 362
 363static void ds2760_battery_set_charged_work(struct work_struct *work)
 364{
 365        char bias;
 366        struct ds2760_device_info *di = container_of(work,
 367                struct ds2760_device_info, set_charged_work.work);
 368
 369        dev_dbg(di->dev, "%s\n", __func__);
 370
 371        ds2760_battery_read_status(di);
 372
 373        /* When we get notified by external circuitry that the battery is
 374         * considered fully charged now, we know that there is no current
 375         * flow any more. However, the ds2760's internal current meter is
 376         * too inaccurate to rely on - spec say something ~15% failure.
 377         * Hence, we use the current offset bias register to compensate
 378         * that error.
 379         */
 380
 381        if (!power_supply_am_i_supplied(&di->bat))
 382                return;
 383
 384        bias = (signed char) di->current_raw +
 385                (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
 386
 387        dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
 388
 389        w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
 390        w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 391        w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 392
 393        /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
 394         * value won't be read back by ds2760_battery_read_status() */
 395        di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
 396}
 397
 398static void ds2760_battery_set_charged(struct power_supply *psy)
 399{
 400        struct ds2760_device_info *di = to_ds2760_device_info(psy);
 401
 402        /* postpone the actual work by 20 secs. This is for debouncing GPIO
 403         * signals and to let the current value settle. See AN4188. */
 404        cancel_delayed_work(&di->set_charged_work);
 405        queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
 406}
 407
 408static int ds2760_battery_get_property(struct power_supply *psy,
 409                                       enum power_supply_property psp,
 410                                       union power_supply_propval *val)
 411{
 412        struct ds2760_device_info *di = to_ds2760_device_info(psy);
 413
 414        switch (psp) {
 415        case POWER_SUPPLY_PROP_STATUS:
 416                val->intval = di->charge_status;
 417                return 0;
 418        default:
 419                break;
 420        }
 421
 422        ds2760_battery_read_status(di);
 423
 424        switch (psp) {
 425        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 426                val->intval = di->voltage_uV;
 427                break;
 428        case POWER_SUPPLY_PROP_CURRENT_NOW:
 429                val->intval = di->current_uA;
 430                break;
 431        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 432                val->intval = di->rated_capacity;
 433                break;
 434        case POWER_SUPPLY_PROP_CHARGE_FULL:
 435                val->intval = di->full_active_uAh;
 436                break;
 437        case POWER_SUPPLY_PROP_CHARGE_EMPTY:
 438                val->intval = di->empty_uAh;
 439                break;
 440        case POWER_SUPPLY_PROP_CHARGE_NOW:
 441                val->intval = di->accum_current_uAh;
 442                break;
 443        case POWER_SUPPLY_PROP_TEMP:
 444                val->intval = di->temp_C;
 445                break;
 446        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 447                val->intval = di->life_sec;
 448                break;
 449        case POWER_SUPPLY_PROP_CAPACITY:
 450                val->intval = di->rem_capacity;
 451                break;
 452        default:
 453                return -EINVAL;
 454        }
 455
 456        return 0;
 457}
 458
 459static int ds2760_battery_set_property(struct power_supply *psy,
 460                                       enum power_supply_property psp,
 461                                       const union power_supply_propval *val)
 462{
 463        struct ds2760_device_info *di = to_ds2760_device_info(psy);
 464
 465        switch (psp) {
 466        case POWER_SUPPLY_PROP_CHARGE_FULL:
 467                /* the interface counts in uAh, convert the value */
 468                ds2760_battery_write_active_full(di, val->intval / 1000L);
 469                break;
 470
 471        case POWER_SUPPLY_PROP_CHARGE_NOW:
 472                /* ds2760_battery_set_current_accum() does the conversion */
 473                ds2760_battery_set_current_accum(di, val->intval);
 474                break;
 475
 476        default:
 477                return -EPERM;
 478        }
 479
 480        return 0;
 481}
 482
 483static int ds2760_battery_property_is_writeable(struct power_supply *psy,
 484                                                enum power_supply_property psp)
 485{
 486        switch (psp) {
 487        case POWER_SUPPLY_PROP_CHARGE_FULL:
 488        case POWER_SUPPLY_PROP_CHARGE_NOW:
 489                return 1;
 490
 491        default:
 492                break;
 493        }
 494
 495        return 0;
 496}
 497
 498static enum power_supply_property ds2760_battery_props[] = {
 499        POWER_SUPPLY_PROP_STATUS,
 500        POWER_SUPPLY_PROP_VOLTAGE_NOW,
 501        POWER_SUPPLY_PROP_CURRENT_NOW,
 502        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 503        POWER_SUPPLY_PROP_CHARGE_FULL,
 504        POWER_SUPPLY_PROP_CHARGE_EMPTY,
 505        POWER_SUPPLY_PROP_CHARGE_NOW,
 506        POWER_SUPPLY_PROP_TEMP,
 507        POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 508        POWER_SUPPLY_PROP_CAPACITY,
 509};
 510
 511static int ds2760_battery_probe(struct platform_device *pdev)
 512{
 513        char status;
 514        int retval = 0;
 515        struct ds2760_device_info *di;
 516
 517        di = kzalloc(sizeof(*di), GFP_KERNEL);
 518        if (!di) {
 519                retval = -ENOMEM;
 520                goto di_alloc_failed;
 521        }
 522
 523        platform_set_drvdata(pdev, di);
 524
 525        di->dev                 = &pdev->dev;
 526        di->w1_dev              = pdev->dev.parent;
 527        di->bat.name            = dev_name(&pdev->dev);
 528        di->bat.type            = POWER_SUPPLY_TYPE_BATTERY;
 529        di->bat.properties      = ds2760_battery_props;
 530        di->bat.num_properties  = ARRAY_SIZE(ds2760_battery_props);
 531        di->bat.get_property    = ds2760_battery_get_property;
 532        di->bat.set_property    = ds2760_battery_set_property;
 533        di->bat.property_is_writeable =
 534                                  ds2760_battery_property_is_writeable;
 535        di->bat.set_charged     = ds2760_battery_set_charged;
 536        di->bat.external_power_changed =
 537                                  ds2760_battery_external_power_changed;
 538
 539        di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 540
 541        /* enable sleep mode feature */
 542        ds2760_battery_read_status(di);
 543        status = di->raw[DS2760_STATUS_REG];
 544        if (pmod_enabled)
 545                status |= DS2760_STATUS_PMOD;
 546        else
 547                status &= ~DS2760_STATUS_PMOD;
 548
 549        ds2760_battery_write_status(di, status);
 550
 551        /* set rated capacity from module param */
 552        if (rated_capacity)
 553                ds2760_battery_write_rated_capacity(di, rated_capacity);
 554
 555        /* set current accumulator if given as parameter.
 556         * this should only be done for bootstrapping the value */
 557        if (current_accum)
 558                ds2760_battery_set_current_accum(di, current_accum);
 559
 560        retval = power_supply_register(&pdev->dev, &di->bat);
 561        if (retval) {
 562                dev_err(di->dev, "failed to register battery\n");
 563                goto batt_failed;
 564        }
 565
 566        INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
 567        INIT_DELAYED_WORK(&di->set_charged_work,
 568                          ds2760_battery_set_charged_work);
 569        di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
 570        if (!di->monitor_wqueue) {
 571                retval = -ESRCH;
 572                goto workqueue_failed;
 573        }
 574        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
 575
 576        goto success;
 577
 578workqueue_failed:
 579        power_supply_unregister(&di->bat);
 580batt_failed:
 581        kfree(di);
 582di_alloc_failed:
 583success:
 584        return retval;
 585}
 586
 587static int ds2760_battery_remove(struct platform_device *pdev)
 588{
 589        struct ds2760_device_info *di = platform_get_drvdata(pdev);
 590
 591        cancel_delayed_work_sync(&di->monitor_work);
 592        cancel_delayed_work_sync(&di->set_charged_work);
 593        destroy_workqueue(di->monitor_wqueue);
 594        power_supply_unregister(&di->bat);
 595        kfree(di);
 596
 597        return 0;
 598}
 599
 600#ifdef CONFIG_PM
 601
 602static int ds2760_battery_suspend(struct platform_device *pdev,
 603                                  pm_message_t state)
 604{
 605        struct ds2760_device_info *di = platform_get_drvdata(pdev);
 606
 607        di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 608
 609        return 0;
 610}
 611
 612static int ds2760_battery_resume(struct platform_device *pdev)
 613{
 614        struct ds2760_device_info *di = platform_get_drvdata(pdev);
 615
 616        di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 617        power_supply_changed(&di->bat);
 618
 619        cancel_delayed_work(&di->monitor_work);
 620        queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
 621
 622        return 0;
 623}
 624
 625#else
 626
 627#define ds2760_battery_suspend NULL
 628#define ds2760_battery_resume NULL
 629
 630#endif /* CONFIG_PM */
 631
 632MODULE_ALIAS("platform:ds2760-battery");
 633
 634static struct platform_driver ds2760_battery_driver = {
 635        .driver = {
 636                .name = "ds2760-battery",
 637        },
 638        .probe    = ds2760_battery_probe,
 639        .remove   = ds2760_battery_remove,
 640        .suspend  = ds2760_battery_suspend,
 641        .resume   = ds2760_battery_resume,
 642};
 643
 644module_platform_driver(ds2760_battery_driver);
 645
 646MODULE_LICENSE("GPL");
 647MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
 648              "Matt Reimer <mreimer@vpop.net>, "
 649              "Anton Vorontsov <cbou@mail.ru>");
 650MODULE_DESCRIPTION("ds2760 battery driver");
 651
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