drivers/power/ds2760_battery.c

   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
  34 struct 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
  63 static unsigned int cache_time = 1000;
  64 module_param(cache_time, uint, 0644);
  65 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  66
  67 static unsigned int pmod_enabled;
  68 module_param(pmod_enabled, bool, 0644);
  69 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
  70
  71 static unsigned int rated_capacity;
  72 module_param(rated_capacity, uint, 0644);
  73 MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
  74
  75 static unsigned int current_accum;
  76 module_param(current_accum, uint, 0644);
  77 MODULE_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. */
  81 static 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 };
 100
 101 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
 102  * temp is in Celsius */
 103 static int battery_interpolate(int array[], int temp)
 104 {
 105         int index, dt;
 106
 107         if (temp <= 0)
 108                 return array[0];
 109         if (temp >= 40)
 110                 return array[4];
 111
 112         index = temp / 10;
 113         dt    = temp % 10;
 114
 115         return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
 116 }
 117
 118 static int ds2760_battery_read_status(struct ds2760_device_info *di)
 119 {
 120         int ret, i, start, count, scale[5];
 121
 122         if (di->update_time && time_before(jiffies, di->update_time +
 123                                            msecs_to_jiffies(cache_time)))
 124                 return 0;
 125
 126         /* The first time we read the entire contents of SRAM/EEPROM,
 127          * but after that we just read the interesting bits that change. */
 128         if (di->update_time == 0) {
 129                 start = 0;
 130                 count = DS2760_DATA_SIZE;
 131         } else {
 132                 start = DS2760_VOLTAGE_MSB;
 133                 count = DS2760_TEMP_LSB - start + 1;
 134         }
 135
 136         ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
 137         if (ret != count) {
 138                 dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
 139                          di->w1_dev);
 140                 return 1;
 141         }
 142
 143         di->update_time = jiffies;
 144
 145         /* DS2760 reports voltage in units of 4.88mV, but the battery class
 146          * reports in units of uV, so convert by multiplying by 4880. */
 147         di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
 148                           (di->raw[DS2760_VOLTAGE_LSB] >> 5);
 149         di->voltage_uV = di->voltage_raw * 4880;
 150
 151         /* DS2760 reports current in signed units of 0.625mA, but the battery
 152          * class reports in units of µA, so convert by multiplying by 625. */
 153         di->current_raw =
 154             (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
 155                           (di->raw[DS2760_CURRENT_LSB] >> 3);
 156         di->current_uA = di->current_raw * 625;
 157
 158         /* DS2760 reports accumulated current in signed units of 0.25mAh. */
 159         di->accum_current_raw =
 160             (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
 161                            di->raw[DS2760_CURRENT_ACCUM_LSB];
 162         di->accum_current_uAh = di->accum_current_raw * 250;
 163
 164         /* DS2760 reports temperature in signed units of 0.125°C, but the
 165          * battery class reports in units of 1/10 °C, so we convert by
 166          * multiplying by .125 * 10 = 1.25. */
 167         di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
 168                                      (di->raw[DS2760_TEMP_LSB] >> 5);
 169         di->temp_C = di->temp_raw + (di->temp_raw / 4);
 170
 171         /* At least some battery monitors (e.g. HP iPAQ) store the battery's
 172          * maximum rated capacity. */
 173         if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
 174                 di->rated_capacity = rated_capacities[
 175                         (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
 176         else
 177                 di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
 178
 179         di->rated_capacity *= 1000; /* convert to µAh */
 180
 181         /* Calculate the full level at the present temperature. */
 182         di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
 183                               di->raw[DS2760_ACTIVE_FULL + 1];
 184
 185         /* If the full_active_uAh value is not given, fall back to the rated
 186          * capacity. This is likely to happen when chips are not part of the
 187          * battery pack and is therefore not bootstrapped. */
 188         if (di->full_active_uAh == 0)
 189                 di->full_active_uAh = di->rated_capacity / 1000L;
 190
 191         scale[0] = di->full_active_uAh;
 192         for (i = 1; i < 5; i++)
 193                 scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
 194
 195         di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
 196         di->full_active_uAh *= 1000; /* convert to µAh */
 197
 198         /* Calculate the empty level at the present temperature. */
 199         scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
 200         for (i = 3; i >= 0; i--)
 201                 scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
 202
 203         di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
 204         di->empty_uAh *= 1000; /* convert to µAh */
 205
 206         if (di->full_active_uAh == di->empty_uAh)
 207                 di->rem_capacity = 0;
 208         else
 209                 /* From Maxim Application Note 131: remaining capacity =
 210                  * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
 211                 di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
 212                                     (di->full_active_uAh - di->empty_uAh);
 213
 214         if (di->rem_capacity < 0)
 215                 di->rem_capacity = 0;
 216         if (di->rem_capacity > 100)
 217                 di->rem_capacity = 100;
 218
 219         if (di->current_uA < -100L)
 220                 di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
 221                                         / (di->current_uA / 100L);
 222         else
 223                 di->life_sec = 0;
 224
 225         return 0;
 226 }
 227
 228 static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
 229                                              unsigned int acr_val)
 230 {
 231         unsigned char acr[2];
 232
 233         /* acr is in units of 0.25 mAh */
 234         acr_val *= 4L;
 235         acr_val /= 1000;
 236
 237         acr[0] = acr_val >> 8;
 238         acr[1] = acr_val & 0xff;
 239
 240         if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
 241                 dev_warn(di->dev, "ACR write failed\n");
 242 }
 243
 244 static void ds2760_battery_update_status(struct ds2760_device_info *di)
 245 {
 246         int old_charge_status = di->charge_status;
 247
 248         ds2760_battery_read_status(di);
 249
 250         if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
 251                 di->full_counter = 0;
 252
 253         if (power_supply_am_i_supplied(&di->bat)) {
 254                 if (di->current_uA > 10000) {
 255                         di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
 256                         di->full_counter = 0;
 257                 } else if (di->current_uA < -5000) {
 258                         if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
 259                                 dev_notice(di->dev, "not enough power to "
 260                                            "charge\n");
 261                         di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 262                         di->full_counter = 0;
 263                 } else if (di->current_uA < 10000 &&
 264                             di->charge_status != POWER_SUPPLY_STATUS_FULL) {
 265
 266                         /* Don't consider the battery to be full unless
 267                          * we've seen the current < 10 mA at least two
 268                          * consecutive times. */
 269
 270                         di->full_counter++;
 271
 272                         if (di->full_counter < 2) {
 273                                 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
 274                         } else {
 275                                 di->charge_status = POWER_SUPPLY_STATUS_FULL;
 276                                 ds2760_battery_set_current_accum(di,
 277                                                 di->full_active_uAh);
 278                         }
 279                 }
 280         } else {
 281                 di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
 282                 di->full_counter = 0;
 283         }
 284
 285         if (di->charge_status != old_charge_status)
 286                 power_supply_changed(&di->bat);
 287 }
 288
 289 static void ds2760_battery_write_status(struct ds2760_device_info *di,
 290                                         char status)
 291 {
 292         if (status == di->raw[DS2760_STATUS_REG])
 293                 return;
 294
 295         w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
 296         w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 297         w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 298 }
 299
 300 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
 301                                                 unsigned char rated_capacity)
 302 {
 303         if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
 304                 return;
 305
 306         w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
 307         w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 308         w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 309 }
 310
 311 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
 312                                              int active_full)
 313 {
 314         unsigned char tmp[2] = {
 315                 active_full >> 8,
 316                 active_full & 0xff
 317         };
 318
 319         if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
 320             tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
 321                 return;
 322
 323         w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
 324         w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
 325         w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
 326
 327         /* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
 328          * values won't be read back by ds2760_battery_read_status() */
 329         di->raw[DS2760_ACTIVE_FULL] = tmp[0];
 330         di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
 331 }
 332
 333 static void ds2760_battery_work(struct work_struct *work)
 334 {
 335         struct ds2760_device_info *di = container_of(work,
 336                 struct ds2760_device_info, monitor_work.work);
 337         const int interval = HZ * 60;
 338
 339         dev_dbg(di->dev, "%s\n", __func__);
 340
 341         ds2760_battery_update_status(di);
 342         queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
 343 }
 344
 345 #define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
 346                                               bat);
 347
 348 static void ds2760_battery_external_power_changed(struct power_supply *psy)
 349 {
 350         struct ds2760_device_info *di = to_ds2760_device_info(psy);
 351
 352         dev_dbg(di->dev, "%s\n", __func__);
 353
 354         cancel_delayed_work(&di->monitor_work);
 355         queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
 356 }
 357
 358
 359 static void ds2760_battery_set_charged_work(struct work_struct *work)
 360 {
 361         char bias;
 362         struct ds2760_device_info *di = container_of(work,
 363                 struct ds2760_device_info, set_charged_work.work);
 364
 365         dev_dbg(di->dev, "%s\n", __func__);
 366
 367         ds2760_battery_read_status(di);
 368
 369         /* When we get notified by external circuitry that the battery is
 370          * considered fully charged now, we know that there is no current
 371          * flow any more. However, the ds2760's internal current meter is
 372          * too inaccurate to rely on - spec say something ~15% failure.
 373          * Hence, we use the current offset bias register to compensate
 374          * that error.
 375          */
 376
 377         if (!power_supply_am_i_supplied(&di->bat))
 378                 return;
 379
 380         bias = (signed char) di->current_raw +
 381                 (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
 382
 383         dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
 384
 385         w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
 386         w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 387         w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
 388
 389         /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
 390          * value won't be read back by ds2760_battery_read_status() */
 391         di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
 392 }
 393
 394 static void ds2760_battery_set_charged(struct power_supply *psy)
 395 {
 396         struct ds2760_device_info *di = to_ds2760_device_info(psy);
 397
 398         /* postpone the actual work by 20 secs. This is for debouncing GPIO
 399          * signals and to let the current value settle. See AN4188. */
 400         cancel_delayed_work(&di->set_charged_work);
 401         queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
 402 }
 403
 404 static int ds2760_battery_get_property(struct power_supply *psy,
 405                                        enum power_supply_property psp,
 406                                        union power_supply_propval *val)
 407 {
 408         struct ds2760_device_info *di = to_ds2760_device_info(psy);
 409
 410         switch (psp) {
 411         case POWER_SUPPLY_PROP_STATUS:
 412                 val->intval = di->charge_status;
 413                 return 0;
 414         default:
 415                 break;
 416         }
 417
 418         ds2760_battery_read_status(di);
 419
 420         switch (psp) {
 421         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 422                 val->intval = di->voltage_uV;
 423                 break;
 424         case POWER_SUPPLY_PROP_CURRENT_NOW:
 425                 val->intval = di->current_uA;
 426                 break;
 427         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 428                 val->intval = di->rated_capacity;
 429                 break;
 430         case POWER_SUPPLY_PROP_CHARGE_FULL:
 431                 val->intval = di->full_active_uAh;
 432                 break;
 433         case POWER_SUPPLY_PROP_CHARGE_EMPTY:
 434                 val->intval = di->empty_uAh;
 435                 break;
 436         case POWER_SUPPLY_PROP_CHARGE_NOW:
 437                 val->intval = di->accum_current_uAh;
 438                 break;
 439         case POWER_SUPPLY_PROP_TEMP:
 440                 val->intval = di->temp_C;
 441                 break;
 442         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 443                 val->intval = di->life_sec;
 444                 break;
 445         case POWER_SUPPLY_PROP_CAPACITY:
 446                 val->intval = di->rem_capacity;
 447                 break;
 448         default:
 449                 return -EINVAL;
 450         }
 451
 452         return 0;
 453 }
 454
 455 static int ds2760_battery_set_property(struct power_supply *psy,
 456                                        enum power_supply_property psp,
 457                                        const union power_supply_propval *val)
 458 {
 459         struct ds2760_device_info *di = to_ds2760_device_info(psy);
 460
 461         switch (psp) {
 462         case POWER_SUPPLY_PROP_CHARGE_FULL:
 463                 /* the interface counts in uAh, convert the value */
 464                 ds2760_battery_write_active_full(di, val->intval / 1000L);
 465                 break;
 466
 467         case POWER_SUPPLY_PROP_CHARGE_NOW:
 468                 /* ds2760_battery_set_current_accum() does the conversion */
 469                 ds2760_battery_set_current_accum(di, val->intval);
 470                 break;
 471
 472         default:
 473                 return -EPERM;
 474         }
 475
 476         return 0;
 477 }
 478
 479 static int ds2760_battery_property_is_writeable(struct power_supply *psy,
 480                                                 enum power_supply_property psp)
 481 {
 482         switch (psp) {
 483         case POWER_SUPPLY_PROP_CHARGE_FULL:
 484         case POWER_SUPPLY_PROP_CHARGE_NOW:
 485                 return 1;
 486
 487         default:
 488                 break;
 489         }
 490
 491         return 0;
 492 }
 493
 494 static enum power_supply_property ds2760_battery_props[] = {
 495         POWER_SUPPLY_PROP_STATUS,
 496         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 497         POWER_SUPPLY_PROP_CURRENT_NOW,
 498         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 499         POWER_SUPPLY_PROP_CHARGE_FULL,
 500         POWER_SUPPLY_PROP_CHARGE_EMPTY,
 501         POWER_SUPPLY_PROP_CHARGE_NOW,
 502         POWER_SUPPLY_PROP_TEMP,
 503         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 504         POWER_SUPPLY_PROP_CAPACITY,
 505 };
 506
 507 static int ds2760_battery_probe(struct platform_device *pdev)
 508 {
 509         char status;
 510         int retval = 0;
 511         struct ds2760_device_info *di;
 512
 513         di = kzalloc(sizeof(*di), GFP_KERNEL);
 514         if (!di) {
 515                 retval = -ENOMEM;
 516                 goto di_alloc_failed;
 517         }
 518
 519         platform_set_drvdata(pdev, di);
 520
 521         di->dev                 = &pdev->dev;
 522         di->w1_dev              = pdev->dev.parent;
 523         di->bat.name            = dev_name(&pdev->dev);
 524         di->bat.type            = POWER_SUPPLY_TYPE_BATTERY;
 525         di->bat.properties      = ds2760_battery_props;
 526         di->bat.num_properties  = ARRAY_SIZE(ds2760_battery_props);
 527         di->bat.get_property    = ds2760_battery_get_property;
 528         di->bat.set_property    = ds2760_battery_set_property;
 529         di->bat.property_is_writeable =
 530                                   ds2760_battery_property_is_writeable;
 531         di->bat.set_charged     = ds2760_battery_set_charged;
 532         di->bat.external_power_changed =
 533                                   ds2760_battery_external_power_changed;
 534
 535         di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 536
 537         /* enable sleep mode feature */
 538         ds2760_battery_read_status(di);
 539         status = di->raw[DS2760_STATUS_REG];
 540         if (pmod_enabled)
 541                 status |= DS2760_STATUS_PMOD;
 542         else
 543                 status &= ~DS2760_STATUS_PMOD;
 544
 545         ds2760_battery_write_status(di, status);
 546
 547         /* set rated capacity from module param */
 548         if (rated_capacity)
 549                 ds2760_battery_write_rated_capacity(di, rated_capacity);
 550
 551         /* set current accumulator if given as parameter.
 552          * this should only be done for bootstrapping the value */
 553         if (current_accum)
 554                 ds2760_battery_set_current_accum(di, current_accum);
 555
 556         retval = power_supply_register(&pdev->dev, &di->bat);
 557         if (retval) {
 558                 dev_err(di->dev, "failed to register battery\n");
 559                 goto batt_failed;
 560         }
 561
 562         INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
 563         INIT_DELAYED_WORK(&di->set_charged_work,
 564                           ds2760_battery_set_charged_work);
 565         di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
 566         if (!di->monitor_wqueue) {
 567                 retval = -ESRCH;
 568                 goto workqueue_failed;
 569         }
 570         queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
 571
 572         goto success;
 573
 574 workqueue_failed:
 575         power_supply_unregister(&di->bat);
 576 batt_failed:
 577         kfree(di);
 578 di_alloc_failed:
 579 success:
 580         return retval;
 581 }
 582
 583 static int ds2760_battery_remove(struct platform_device *pdev)
 584 {
 585         struct ds2760_device_info *di = platform_get_drvdata(pdev);
 586
 587         cancel_delayed_work_sync(&di->monitor_work);
 588         cancel_delayed_work_sync(&di->set_charged_work);
 589         destroy_workqueue(di->monitor_wqueue);
 590         power_supply_unregister(&di->bat);
 591         kfree(di);
 592
 593         return 0;
 594 }
 595
 596 #ifdef CONFIG_PM
 597
 598 static int ds2760_battery_suspend(struct platform_device *pdev,
 599                                   pm_message_t state)
 600 {
 601         struct ds2760_device_info *di = platform_get_drvdata(pdev);
 602
 603         di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 604
 605         return 0;
 606 }
 607
 608 static int ds2760_battery_resume(struct platform_device *pdev)
 609 {
 610         struct ds2760_device_info *di = platform_get_drvdata(pdev);
 611
 612         di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 613         power_supply_changed(&di->bat);
 614
 615         cancel_delayed_work(&di->monitor_work);
 616         queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
 617
 618         return 0;
 619 }
 620
 621 #else
 622
 623 #define ds2760_battery_suspend NULL
 624 #define ds2760_battery_resume NULL
 625
 626 #endif /* CONFIG_PM */
 627
 628 MODULE_ALIAS("platform:ds2760-battery");
 629
 630 static struct platform_driver ds2760_battery_driver = {
 631         .driver = {
 632                 .name = "ds2760-battery",
 633         },
 634         .probe    = ds2760_battery_probe,
 635         .remove   = ds2760_battery_remove,
 636         .suspend  = ds2760_battery_suspend,
 637         .resume   = ds2760_battery_resume,
 638 };
 639
 640 static int __init ds2760_battery_init(void)
 641 {
 642         return platform_driver_register(&ds2760_battery_driver);
 643 }
 644
 645 static void __exit ds2760_battery_exit(void)
 646 {
 647         platform_driver_unregister(&ds2760_battery_driver);
 648 }
 649
 650 module_init(ds2760_battery_init);
 651 module_exit(ds2760_battery_exit);
 652
 653 MODULE_LICENSE("GPL");
 654 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
 655               "Matt Reimer <mreimer@vpop.net>, "
 656               "Anton Vorontsov <cbou@mail.ru>");
 657 MODULE_DESCRIPTION("ds2760 battery driver");