drivers/power/bq27x00_battery.c

   1 /*
   2  * BQ27x00 battery driver
   3  *
   4  * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
   5  * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
   6  * Copyright (C) 2010 Lars-Peter Clausen <lars@metafoo.de>
   7  *
   8  * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
   9  *
  10  * This package is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  */
  19 #include <linux/module.h>
  20 #include <linux/param.h>
  21 #include <linux/jiffies.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/delay.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/power_supply.h>
  26 #include <linux/idr.h>
  27 #include <linux/i2c.h>
  28 #include <linux/slab.h>
  29 #include <asm/unaligned.h>
  30
  31 #include <linux/power/bq27x00_battery.h>
  32
  33 #define DRIVER_VERSION                  "1.1.0"
  34
  35 #define BQ27x00_REG_TEMP                0x06
  36 #define BQ27x00_REG_VOLT                0x08
  37 #define BQ27x00_REG_AI                  0x14
  38 #define BQ27x00_REG_FLAGS               0x0A
  39 #define BQ27x00_REG_LMD                 0x12
  40 #define BQ27x00_REG_TTE                 0x16
  41 #define BQ27x00_REG_TTF                 0x18
  42 #define BQ27x00_REG_TTECP               0x26
  43
  44 #define BQ27000_REG_RSOC                0x0B /* Relative State-of-Charge */
  45 #define BQ27000_FLAG_VDQ                BIT(3)
  46 #define BQ27000_FLAG_CHGS               BIT(7)
  47
  48 #define BQ27500_REG_SOC                 0x2c
  49 #define BQ27500_FLAG_DSC                BIT(0)
  50 #define BQ27500_FLAG_FC                 BIT(9)
  51
  52 struct bq27x00_device_info;
  53 struct bq27x00_access_methods {
  54         int (*read)(u8 reg, bool single, struct bq27x00_device_info *di);
  55 };
  56
  57 enum bq27x00_chip { BQ27000, BQ27500 };
  58
  59 struct bq27x00_values {
  60         int temperature;
  61         int voltage;
  62         int current_now;
  63         int time_to_empty;
  64         int time_to_empty_avg;
  65         int time_to_full;
  66         int charge_full;
  67         int capacity;
  68         int flags;
  69 };
  70
  71 struct bq27x00_device_info {
  72         struct device           *dev;
  73         int                     id;
  74         enum bq27x00_chip       chip;
  75
  76         struct bq27x00_access_methods   bus;
  77
  78         struct power_supply     bat;
  79
  80         struct bq27x00_values values;
  81
  82         unsigned long last_update;
  83         struct delayed_work work;
  84 };
  85
  86 static enum power_supply_property bq27x00_battery_props[] = {
  87         POWER_SUPPLY_PROP_STATUS,
  88         POWER_SUPPLY_PROP_PRESENT,
  89         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  90         POWER_SUPPLY_PROP_CURRENT_NOW,
  91         POWER_SUPPLY_PROP_CAPACITY,
  92         POWER_SUPPLY_PROP_TEMP,
  93         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
  94         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
  95         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
  96         POWER_SUPPLY_PROP_TECHNOLOGY,
  97         POWER_SUPPLY_PROP_CHARGE_FULL,
  98         POWER_SUPPLY_PROP_HEALTH,
  99 };
 100
 101 /*
 102  * Common code for BQ27x00 devices
 103  */
 104
 105 static int bq27x00_read(u8 reg, bool single, struct bq27x00_device_info *di)
 106 {
 107         return di->bus.read(reg, single, di);
 108 }
 109
 110 /*
 111  * Return the battery Voltage in milivolts
 112  * Or < 0 if something fails.
 113  */
 114 static int bq27x00_battery_read_voltage(struct bq27x00_device_info *di)
 115 {
 116         int volt;
 117
 118         volt = bq27x00_read(BQ27x00_REG_VOLT, 0, di);
 119         if (volt < 0)
 120                 return volt;
 121
 122         return volt * 1000;
 123 }
 124
 125 /*
 126  * Return the battery Relative State-of-Charge
 127  * Or < 0 if something fails.
 128  */
 129 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 130 {
 131         int rsoc;
 132
 133         if (di->chip == BQ27500)
 134                 rsoc = bq27x00_read(BQ27500_REG_SOC, 0, di);
 135         else
 136                 rsoc = bq27x00_read(BQ27000_REG_RSOC, 1, di);
 137         if (rsoc < 0) {
 138                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 139         }
 140
 141         return rsoc;
 142 }
 143
 144 /*
 145  * Read a time register.
 146  * Return < 0 if something fails.
 147  */
 148 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, int reg)
 149 {
 150         int tval;
 151
 152         tval = bq27x00_read(reg, 0, di);
 153         if (tval < 0) {
 154                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 155                 return tval;
 156         }
 157
 158         if (tval == 65535)
 159                 return -ENODATA;
 160
 161         return tval * 60;
 162 }
 163
 164 static int bq27x00_battery_read_charge_full(struct bq27x00_device_info *di)
 165 {
 166         int charge;
 167
 168         charge = bq27x00_read(BQ27x00_REG_LMD, 0, di);
 169         if (charge < 0) {
 170                 dev_err(di->dev, "error reading register charge full: %d\n", charge);
 171                 return charge;
 172         }
 173
 174         if (di->chip == BQ27500)
 175                 charge *= 1000;
 176         else
 177                 charge = charge * 357 / 2;
 178
 179         return charge;
 180 }
 181
 182 static void bq27x00_update(struct bq27x00_device_info *di)
 183 {
 184         struct bq27x00_values values = {0, };
 185
 186         values.voltage = bq27x00_battery_read_voltage(di);
 187         if (values.voltage >= 0) {
 188                 values.flags = bq27x00_read(BQ27x00_REG_FLAGS, di->chip == BQ27500, di);
 189                 values.current_now = bq27x00_read(BQ27x00_REG_AI, 0, di);
 190                 values.capacity = bq27x00_battery_read_rsoc(di);
 191                 values.temperature = bq27x00_read(BQ27x00_REG_TEMP, 0, di);
 192                 values.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 193                 values.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 194                 values.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 195                 values.charge_full = bq27x00_battery_read_charge_full(di);
 196         }
 197
 198         if (memcmp(&di->values, &values, sizeof(values)) != 0) {
 199                 di->values = values;
 200                 power_supply_changed(&di->bat);
 201         }
 202
 203         di->last_update = jiffies;
 204 }
 205
 206 /*
 207  * Return the battery temperature in tenths of degree Celsius
 208  * Or < 0 if something fails.
 209  */
 210 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
 211         union power_supply_propval *val)
 212 {
 213         if (di->values.temperature < 0)
 214                 return di->values.temperature;
 215
 216         if (di->chip == BQ27500)
 217                 val->intval = di->values.temperature - 2731;
 218         else
 219                 val->intval = ((di->values.temperature * 5) - 5463) >> 1;
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * Return the battery average current
 226  * Note that current can be negative signed as well
 227  * Or 0 if something fails.
 228  */
 229 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 230         union power_supply_propval *val)
 231 {
 232         int curr = 0;
 233
 234         if (di->values.current_now < 0)
 235                 return di->values.current_now;
 236
 237         if (di->chip == BQ27500) {
 238                 /* bq27500 returns signed value */
 239                 val->intval = (int)((s16)di->values.current_now) * 1000;
 240         } else {
 241                 if (di->values.flags < 0)
 242                         return di->values.flags;
 243
 244                 curr = di->values.current_now;
 245                 if (di->values.flags & BQ27000_FLAG_CHGS) {
 246                         dev_dbg(di->dev, "negative current!\n");
 247                         curr = -curr;
 248                 }
 249
 250                 val->intval = curr * 3570 / 20;
 251         }
 252
 253         return 0;
 254 }
 255
 256 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 257         union power_supply_propval *val)
 258 {
 259         int status;
 260
 261         if (di->values.flags < 0)
 262                 return di->values.flags;
 263
 264         if (di->chip == BQ27500) {
 265                 if (di->values.flags & BQ27500_FLAG_FC)
 266                         status = POWER_SUPPLY_STATUS_FULL;
 267                 else if (di->values.flags & BQ27500_FLAG_DSC)
 268                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 269                 else
 270                         status = POWER_SUPPLY_STATUS_CHARGING;
 271         } else {
 272                 if (di->values.flags & BQ27000_FLAG_CHGS)
 273                         status = POWER_SUPPLY_STATUS_CHARGING;
 274                 else if (di->values.time_to_full == 0)
 275                         status = POWER_SUPPLY_STATUS_FULL;
 276                 else if (power_supply_am_i_supplied(&di->bat))
 277                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 278                 else
 279                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 280         }
 281
 282         val->intval = status;
 283
 284         return 0;
 285 }
 286
 287 static int bq27x00_simple_value(int value,
 288         union power_supply_propval *val)
 289 {
 290         if (value < 0)
 291                 return value;
 292
 293         val->intval = value;
 294
 295         return 0;
 296 }
 297
 298 static int bq27x00_battery_health(struct bq27x00_device_info *di,
 299         union power_supply_propval *val)
 300 {
 301         if (di->values.flags < 0)
 302                 return di->values.flags;
 303
 304         if (di->values.flags & BQ27000_FLAG_VDQ)
 305                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
 306         else
 307                 val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
 308
 309         return 0;
 310 }
 311
 312 #define to_bq27x00_device_info(x) container_of((x), \
 313                                 struct bq27x00_device_info, bat);
 314
 315 static int bq27x00_battery_get_property(struct power_supply *psy,
 316                                         enum power_supply_property psp,
 317                                         union power_supply_propval *val)
 318 {
 319         int ret = 0;
 320         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 321
 322         if (time_is_before_jiffies(di->last_update + 6 * HZ)) {
 323                 cancel_delayed_work(&di->work);
 324                 bq27x00_update(di);
 325                 schedule_delayed_work(&di->work, 60 * HZ);
 326         }
 327
 328         if (psp != POWER_SUPPLY_PROP_PRESENT && di->values.voltage <= 0)
 329                 return -ENODEV;
 330
 331         switch (psp) {
 332         case POWER_SUPPLY_PROP_STATUS:
 333                 ret = bq27x00_battery_status(di, val);
 334                 break;
 335         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 336                 ret = bq27x00_simple_value(di->values.voltage, val);
 337                 break;
 338         case POWER_SUPPLY_PROP_PRESENT:
 339                 val->intval = di->values.voltage <= 0 ? 0 : 1;
 340                 break;
 341         case POWER_SUPPLY_PROP_CURRENT_NOW:
 342                 ret = bq27x00_battery_current(di, val);
 343                 break;
 344         case POWER_SUPPLY_PROP_CAPACITY:
 345                 ret = bq27x00_simple_value(di->values.capacity, val);
 346                 break;
 347         case POWER_SUPPLY_PROP_TEMP:
 348                 ret = bq27x00_battery_temperature(di, val);
 349                 break;
 350         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 351                 ret = bq27x00_simple_value(di->values.time_to_empty, val);
 352                 break;
 353         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 354                 ret = bq27x00_simple_value(di->values.time_to_empty_avg, val);
 355                 break;
 356         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 357                 ret = bq27x00_simple_value(di->values.time_to_full, val);
 358                 break;
 359         case POWER_SUPPLY_PROP_TECHNOLOGY:
 360                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 361                 break;
 362         case POWER_SUPPLY_PROP_CHARGE_FULL:
 363                 ret = bq27x00_simple_value(di->values.charge_full, val);
 364                 break;
 365         case POWER_SUPPLY_PROP_HEALTH:
 366                 ret = bq27x00_battery_health(di, val);
 367                 break;
 368         default:
 369                 return -EINVAL;
 370         }
 371
 372         return ret;
 373 }
 374
 375 static void bq27x00_battery_work(struct work_struct *work)
 376 {
 377         struct bq27x00_device_info *di =
 378                 container_of(work, struct bq27x00_device_info, work.work);
 379
 380         bq27x00_update(di);
 381         schedule_delayed_work(&di->work, 60 * HZ);
 382 }
 383
 384 static void bq27x00_external_power_changed(struct power_supply *psy)
 385 {
 386         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 387
 388         schedule_delayed_work(&di->work, 0);
 389 }
 390
 391 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 392 {
 393         int ret;
 394
 395         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 396         di->bat.properties = bq27x00_battery_props;
 397         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 398         di->bat.get_property = bq27x00_battery_get_property;
 399         di->bat.external_power_changed = bq27x00_external_power_changed;
 400
 401         INIT_DELAYED_WORK(&di->work, bq27x00_battery_work);
 402
 403         ret = power_supply_register(di->dev, &di->bat);
 404         if (ret) {
 405                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 406                 return ret;
 407         }
 408
 409         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 410
 411         bq27x00_update(di);
 412
 413         return 0;
 414 }
 415
 416
 417 /* i2c specific code */
 418 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 419
 420 /* If the system has several batteries we need a different name for each
 421  * of them...
 422  */
 423 static DEFINE_IDR(battery_id);
 424 static DEFINE_MUTEX(battery_mutex);
 425
 426 static int bq27x00_read_i2c(u8 reg, bool single, struct bq27x00_device_info *di)
 427 {
 428         struct i2c_client *client = to_i2c_client(di->dev);
 429         struct i2c_msg msg[1];
 430         unsigned char data[2];
 431         int ret;
 432
 433         if (!client->adapter)
 434                 return -ENODEV;
 435
 436         msg->addr = client->addr;
 437         msg->flags = 0;
 438         msg->len = 1;
 439         msg->buf = data;
 440
 441         data[0] = reg;
 442         ret = i2c_transfer(client->adapter, msg, 1);
 443
 444         if (ret >= 0) {
 445                 if (!single)
 446                         msg->len = 2;
 447                 else
 448                         msg->len = 1;
 449
 450                 msg->flags = I2C_M_RD;
 451                 if (ret >= 0) {
 452                         if (!single)
 453                                 ret = get_unaligned_le16(data);
 454                         else
 455                                 ret = data[0];
 456                 }
 457         }
 458         return ret;
 459 }
 460
 461 static int bq27x00_battery_probe(struct i2c_client *client,
 462                                  const struct i2c_device_id *id)
 463 {
 464         char *name;
 465         struct bq27x00_device_info *di;
 466         int num;
 467         int retval = 0;
 468
 469         /* Get new ID for the new battery device */
 470         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 471         if (retval == 0)
 472                 return -ENOMEM;
 473         mutex_lock(&battery_mutex);
 474         retval = idr_get_new(&battery_id, client, &num);
 475         mutex_unlock(&battery_mutex);
 476         if (retval < 0)
 477                 return retval;
 478
 479         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 480         if (!name) {
 481                 dev_err(&client->dev, "failed to allocate device name\n");
 482                 retval = -ENOMEM;
 483                 goto batt_failed_1;
 484         }
 485
 486         di = kzalloc(sizeof(*di), GFP_KERNEL);
 487         if (!di) {
 488                 dev_err(&client->dev, "failed to allocate device info data\n");
 489                 retval = -ENOMEM;
 490                 goto batt_failed_2;
 491         }
 492
 493         di->id = num;
 494         di->chip = id->driver_data;
 495
 496         i2c_set_clientdata(client, di);
 497
 498         di->dev = &client->dev;
 499         di->bat.name = name;
 500
 501         di->bus.read = &bq27x00_read_i2c;
 502
 503         if (bq27x00_powersupply_init(di))
 504                 goto batt_failed_3;
 505
 506         return 0;
 507
 508 batt_failed_3:
 509         kfree(di);
 510 batt_failed_2:
 511         kfree(name);
 512 batt_failed_1:
 513         mutex_lock(&battery_mutex);
 514         idr_remove(&battery_id, num);
 515         mutex_unlock(&battery_mutex);
 516
 517         return retval;
 518 }
 519
 520 static int bq27x00_battery_remove(struct i2c_client *client)
 521 {
 522         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 523
 524         power_supply_unregister(&di->bat);
 525
 526         kfree(di->bat.name);
 527
 528         mutex_lock(&battery_mutex);
 529         idr_remove(&battery_id, di->id);
 530         mutex_unlock(&battery_mutex);
 531
 532         kfree(di);
 533
 534         return 0;
 535 }
 536
 537 static const struct i2c_device_id bq27x00_id[] = {
 538         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 539         { "bq27500", BQ27500 },
 540         {},
 541 };
 542
 543 static struct i2c_driver bq27x00_battery_driver = {
 544         .driver = {
 545                 .name = "bq27x00-battery",
 546         },
 547         .probe = bq27x00_battery_probe,
 548         .remove = bq27x00_battery_remove,
 549         .id_table = bq27x00_id,
 550 };
 551
 552 static inline int bq27x00_battery_i2c_init(void)
 553 {
 554         int ret = i2c_add_driver(&bq27x00_battery_driver);
 555         if (ret)
 556                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 557
 558         return ret;
 559 }
 560
 561 static inline void bq27x00_battery_i2c_exit(void)
 562 {
 563         i2c_del_driver(&bq27x00_battery_driver);
 564 }
 565
 566 #else
 567
 568 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 569 static inline void bq27x00_battery_i2c_exit(void) {};
 570
 571 #endif
 572
 573 /* platform specific code */
 574 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 575
 576 static int bq27000_read_platform(u8 reg, bool single,
 577                         struct bq27x00_device_info *di)
 578 {
 579         struct device *dev = di->dev;
 580         struct bq27000_platform_data *pdata = dev->platform_data;
 581         unsigned int timeout = 3;
 582         int upper, lower;
 583         int temp;
 584
 585         if (!single) {
 586                 /* Make sure the value has not changed in between reading the lower and
 587                  * the upper part */
 588                 upper = pdata->read(dev, reg + 1);
 589                 do {
 590                         temp = upper;
 591                         if (upper < 0)
 592                                 return upper;
 593
 594                         lower = pdata->read(dev, reg);
 595                         if (lower < 0)
 596                                 return lower;
 597
 598                         upper = pdata->read(dev, reg + 1);
 599                 } while(temp != upper && --timeout);
 600
 601                 if (timeout == 0)
 602                         return -ETIMEDOUT;
 603
 604                 return (upper << 8) | lower;
 605         }
 606
 607         return pdata->read(dev, reg);
 608 }
 609
 610 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 611 {
 612         struct bq27x00_device_info *di;
 613         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 614         int ret;
 615
 616         if (!pdata) {
 617                 dev_err(&pdev->dev, "no platform_data supplied\n");
 618                 return -EINVAL;
 619         }
 620
 621         if (!pdata->read) {
 622                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 623                 return -EINVAL;
 624         }
 625
 626         di = kzalloc(sizeof(*di), GFP_KERNEL);
 627         if (!di) {
 628                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 629                 return -ENOMEM;
 630         }
 631
 632         platform_set_drvdata(pdev, di);
 633
 634         di->dev = &pdev->dev;
 635         di->chip = BQ27000;
 636
 637         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 638         di->bus.read = &bq27000_read_platform;
 639
 640         ret = bq27x00_powersupply_init(di);
 641         if (ret)
 642                 goto err_free;
 643
 644         return 0;
 645
 646 err_free:
 647         platform_set_drvdata(pdev, NULL);
 648         kfree(di);
 649
 650         return ret;
 651 }
 652
 653 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 654 {
 655         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 656
 657         power_supply_unregister(&di->bat);
 658         platform_set_drvdata(pdev, NULL);
 659         kfree(di);
 660
 661         return 0;
 662 }
 663
 664 static struct platform_driver bq27000_battery_driver = {
 665         .probe  = bq27000_battery_probe,
 666         .remove = __devexit_p(bq27000_battery_remove),
 667         .driver = {
 668                 .name = "bq27000-battery",
 669                 .owner = THIS_MODULE,
 670         },
 671 };
 672
 673 static inline int bq27x00_battery_platform_init(void)
 674 {
 675         int ret = platform_driver_register(&bq27000_battery_driver);
 676         if (ret)
 677                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 678
 679         return ret;
 680 }
 681
 682 static inline void bq27x00_battery_platform_exit(void)
 683 {
 684         platform_driver_unregister(&bq27000_battery_driver);
 685 }
 686
 687 #else
 688
 689 static inline int bq27x00_battery_platform_init(void) { return 0; }
 690 static inline void bq27x00_battery_platform_exit(void) {};
 691
 692 #endif
 693
 694 /*
 695  * Module stuff
 696  */
 697
 698 static int __init bq27x00_battery_init(void)
 699 {
 700         int ret;
 701
 702         ret = bq27x00_battery_i2c_init();
 703         if (ret)
 704             return ret;
 705
 706         ret = bq27x00_battery_platform_init();
 707         if (ret)
 708             bq27x00_battery_i2c_exit();
 709
 710         return ret;
 711 }
 712 module_init(bq27x00_battery_init);
 713
 714 static void __exit bq27x00_battery_exit(void)
 715 {
 716         bq27x00_battery_platform_exit();
 717         bq27x00_battery_i2c_exit();
 718 }
 719 module_exit(bq27x00_battery_exit);
 720
 721 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 722 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 723 MODULE_LICENSE("GPL");