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) 2010-2011 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
  20 /*
  21  * Datasheets:
  22  * http://focus.ti.com/docs/prod/folders/print/bq27000.html
  23  * http://focus.ti.com/docs/prod/folders/print/bq27500.html
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/param.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/delay.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/power_supply.h>
  33 #include <linux/idr.h>
  34 #include <linux/i2c.h>
  35 #include <linux/slab.h>
  36 #include <asm/unaligned.h>
  37
  38 #include <linux/power/bq27x00_battery.h>
  39
  40 #define DRIVER_VERSION                  "1.2.0"
  41
  42 #define BQ27x00_REG_TEMP                0x06
  43 #define BQ27x00_REG_VOLT                0x08
  44 #define BQ27x00_REG_AI                  0x14
  45 #define BQ27x00_REG_FLAGS               0x0A
  46 #define BQ27x00_REG_TTE                 0x16
  47 #define BQ27x00_REG_TTF                 0x18
  48 #define BQ27x00_REG_TTECP               0x26
  49 #define BQ27x00_REG_NAC                 0x0C /* Nominal available capaciy */
  50 #define BQ27x00_REG_LMD                 0x12 /* Last measured discharge */
  51 #define BQ27x00_REG_CYCT                0x2A /* Cycle count total */
  52 #define BQ27x00_REG_AE                  0x22 /* Available enery */
  53
  54 #define BQ27000_REG_RSOC                0x0B /* Relative State-of-Charge */
  55 #define BQ27000_REG_ILMD                0x76 /* Initial last measured discharge */
  56 #define BQ27000_FLAG_CHGS               BIT(7)
  57
  58 #define BQ27500_REG_SOC                 0x2c
  59 #define BQ27500_REG_DCAP                0x3C /* Design capacity */
  60 #define BQ27500_FLAG_DSC                BIT(0)
  61 #define BQ27500_FLAG_FC                 BIT(9)
  62
  63 #define BQ27000_RS                      20 /* Resistor sense */
  64
  65 struct bq27x00_device_info;
  66 struct bq27x00_access_methods {
  67         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  68 };
  69
  70 enum bq27x00_chip { BQ27000, BQ27500 };
  71
  72 struct bq27x00_reg_cache {
  73         int temperature;
  74         int time_to_empty;
  75         int time_to_empty_avg;
  76         int time_to_full;
  77         int charge_full;
  78         int charge_counter;
  79         int capacity;
  80         int flags;
  81
  82         int current_now;
  83 };
  84
  85 struct bq27x00_device_info {
  86         struct device           *dev;
  87         int                     id;
  88         enum bq27x00_chip       chip;
  89
  90         struct bq27x00_reg_cache cache;
  91         int charge_design_full;
  92
  93         unsigned long last_update;
  94         struct delayed_work work;
  95
  96         struct power_supply     bat;
  97
  98         struct bq27x00_access_methods bus;
  99
 100         struct mutex lock;
 101 };
 102
 103 static enum power_supply_property bq27x00_battery_props[] = {
 104         POWER_SUPPLY_PROP_STATUS,
 105         POWER_SUPPLY_PROP_PRESENT,
 106         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 107         POWER_SUPPLY_PROP_CURRENT_NOW,
 108         POWER_SUPPLY_PROP_CAPACITY,
 109         POWER_SUPPLY_PROP_TEMP,
 110         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 111         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 112         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 113         POWER_SUPPLY_PROP_TECHNOLOGY,
 114         POWER_SUPPLY_PROP_CHARGE_FULL,
 115         POWER_SUPPLY_PROP_CHARGE_NOW,
 116         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 117         POWER_SUPPLY_PROP_CHARGE_COUNTER,
 118         POWER_SUPPLY_PROP_ENERGY_NOW,
 119 };
 120
 121 static unsigned int poll_interval = 360;
 122 module_param(poll_interval, uint, 0644);
 123 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 124                                 "0 disables polling");
 125
 126 /*
 127  * Common code for BQ27x00 devices
 128  */
 129
 130 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 131                 bool single)
 132 {
 133         return di->bus.read(di, reg, single);
 134 }
 135
 136 /*
 137  * Return the battery Relative State-of-Charge
 138  * Or < 0 if something fails.
 139  */
 140 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 141 {
 142         int rsoc;
 143
 144         if (di->chip == BQ27500)
 145                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 146         else
 147                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 148
 149         if (rsoc < 0)
 150                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 151
 152         return rsoc;
 153 }
 154
 155 /*
 156  * Return a battery charge value in µAh
 157  * Or < 0 if something fails.
 158  */
 159 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 160 {
 161         int charge;
 162
 163         charge = bq27x00_read(di, reg, false);
 164         if (charge < 0) {
 165                 dev_err(di->dev, "error reading nominal available capacity\n");
 166                 return charge;
 167         }
 168
 169         if (di->chip == BQ27500)
 170                 charge *= 1000;
 171         else
 172                 charge = charge * 3570 / BQ27000_RS;
 173
 174         return charge;
 175 }
 176
 177 /*
 178  * Return the battery Nominal available capaciy in µAh
 179  * Or < 0 if something fails.
 180  */
 181 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 182 {
 183         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 184 }
 185
 186 /*
 187  * Return the battery Last measured discharge in µAh
 188  * Or < 0 if something fails.
 189  */
 190 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 191 {
 192         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 193 }
 194
 195 /*
 196  * Return the battery Initial last measured discharge in µAh
 197  * Or < 0 if something fails.
 198  */
 199 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 200 {
 201         int ilmd;
 202
 203         if (di->chip == BQ27500)
 204                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 205         else
 206                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 207
 208         if (ilmd < 0) {
 209                 dev_err(di->dev, "error reading initial last measured discharge\n");
 210                 return ilmd;
 211         }
 212
 213         if (di->chip == BQ27500)
 214                 ilmd *= 1000;
 215         else
 216                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 217
 218         return ilmd;
 219 }
 220
 221 /*
 222  * Return the battery Cycle count total
 223  * Or < 0 if something fails.
 224  */
 225 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 226 {
 227         int cyct;
 228
 229         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 230         if (cyct < 0)
 231                 dev_err(di->dev, "error reading cycle count total\n");
 232
 233         return cyct;
 234 }
 235
 236 /*
 237  * Read a time register.
 238  * Return < 0 if something fails.
 239  */
 240 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 241 {
 242         int tval;
 243
 244         tval = bq27x00_read(di, reg, false);
 245         if (tval < 0) {
 246                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 247                 return tval;
 248         }
 249
 250         if (tval == 65535)
 251                 return -ENODATA;
 252
 253         return tval * 60;
 254 }
 255
 256 static void bq27x00_update(struct bq27x00_device_info *di)
 257 {
 258         struct bq27x00_reg_cache cache = {0, };
 259         bool is_bq27500 = di->chip == BQ27500;
 260
 261         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 262         if (cache.flags >= 0) {
 263                 cache.capacity = bq27x00_battery_read_rsoc(di);
 264                 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 265                 cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 266                 cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 267                 cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 268                 cache.charge_full = bq27x00_battery_read_lmd(di);
 269                 cache.charge_counter = bq27x00_battery_read_cyct(di);
 270
 271                 if (!is_bq27500)
 272                         cache.current_now = bq27x00_read(di, BQ27x00_REG_AI, false);
 273
 274                 /* We only have to read charge design full once */
 275                 if (di->charge_design_full <= 0)
 276                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 277         }
 278
 279         /* Ignore current_now which is a snapshot of the current battery state
 280          * and is likely to be different even between two consecutive reads */
 281         if (memcmp(&di->cache, &cache, sizeof(cache) - sizeof(int)) != 0) {
 282                 di->cache = cache;
 283                 power_supply_changed(&di->bat);
 284         }
 285
 286         di->last_update = jiffies;
 287 }
 288
 289 static void bq27x00_battery_poll(struct work_struct *work)
 290 {
 291         struct bq27x00_device_info *di =
 292                 container_of(work, struct bq27x00_device_info, work.work);
 293
 294         bq27x00_update(di);
 295
 296         if (poll_interval > 0) {
 297                 /* The timer does not have to be accurate. */
 298                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 299                 schedule_delayed_work(&di->work, poll_interval * HZ);
 300         }
 301 }
 302
 303
 304 /*
 305  * Return the battery temperature in tenths of degree Celsius
 306  * Or < 0 if something fails.
 307  */
 308 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
 309         union power_supply_propval *val)
 310 {
 311         if (di->cache.temperature < 0)
 312                 return di->cache.temperature;
 313
 314         if (di->chip == BQ27500)
 315                 val->intval = di->cache.temperature - 2731;
 316         else
 317                 val->intval = ((di->cache.temperature * 5) - 5463) / 2;
 318
 319         return 0;
 320 }
 321
 322 /*
 323  * Return the battery average current
 324  * Note that current can be negative signed as well
 325  * Or 0 if something fails.
 326  */
 327 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 328         union power_supply_propval *val)
 329 {
 330         int curr;
 331
 332         if (di->chip == BQ27500)
 333             curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 334         else
 335             curr = di->cache.current_now;
 336
 337         if (curr < 0)
 338                 return curr;
 339
 340         if (di->chip == BQ27500) {
 341                 /* bq27500 returns signed value */
 342                 val->intval = (int)((s16)curr) * 1000;
 343         } else {
 344                 if (di->cache.flags & BQ27000_FLAG_CHGS) {
 345                         dev_dbg(di->dev, "negative current!\n");
 346                         curr = -curr;
 347                 }
 348
 349                 val->intval = curr * 3570 / BQ27000_RS;
 350         }
 351
 352         return 0;
 353 }
 354
 355 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 356         union power_supply_propval *val)
 357 {
 358         int status;
 359
 360         if (di->chip == BQ27500) {
 361                 if (di->cache.flags & BQ27500_FLAG_FC)
 362                         status = POWER_SUPPLY_STATUS_FULL;
 363                 else if (di->cache.flags & BQ27500_FLAG_DSC)
 364                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 365                 else
 366                         status = POWER_SUPPLY_STATUS_CHARGING;
 367         } else {
 368                 if (di->cache.flags & BQ27000_FLAG_CHGS)
 369                         status = POWER_SUPPLY_STATUS_CHARGING;
 370                 else
 371                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 372         }
 373
 374         val->intval = status;
 375
 376         return 0;
 377 }
 378
 379 /*
 380  * Return the battery Voltage in milivolts
 381  * Or < 0 if something fails.
 382  */
 383 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 384         union power_supply_propval *val)
 385 {
 386         int volt;
 387
 388         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 389         if (volt < 0)
 390                 return volt;
 391
 392         val->intval = volt * 1000;
 393
 394         return 0;
 395 }
 396
 397 /*
 398  * Return the battery Available energy in µWh
 399  * Or < 0 if something fails.
 400  */
 401 static int bq27x00_battery_energy(struct bq27x00_device_info *di,
 402         union power_supply_propval *val)
 403 {
 404         int ae;
 405
 406         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 407         if (ae < 0) {
 408                 dev_err(di->dev, "error reading available energy\n");
 409                 return ae;
 410         }
 411
 412         if (di->chip == BQ27500)
 413                 ae *= 1000;
 414         else
 415                 ae = ae * 29200 / BQ27000_RS;
 416
 417         val->intval = ae;
 418
 419         return 0;
 420 }
 421
 422
 423 static int bq27x00_simple_value(int value,
 424         union power_supply_propval *val)
 425 {
 426         if (value < 0)
 427                 return value;
 428
 429         val->intval = value;
 430
 431         return 0;
 432 }
 433
 434 #define to_bq27x00_device_info(x) container_of((x), \
 435                                 struct bq27x00_device_info, bat);
 436
 437 static int bq27x00_battery_get_property(struct power_supply *psy,
 438                                         enum power_supply_property psp,
 439                                         union power_supply_propval *val)
 440 {
 441         int ret = 0;
 442         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 443
 444         mutex_lock(&di->lock);
 445         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 446                 cancel_delayed_work_sync(&di->work);
 447                 bq27x00_battery_poll(&di->work.work);
 448         }
 449         mutex_unlock(&di->lock);
 450
 451         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 452                 return -ENODEV;
 453
 454         switch (psp) {
 455         case POWER_SUPPLY_PROP_STATUS:
 456                 ret = bq27x00_battery_status(di, val);
 457                 break;
 458         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 459                 ret = bq27x00_battery_voltage(di, val);
 460                 break;
 461         case POWER_SUPPLY_PROP_PRESENT:
 462                 val->intval = di->cache.flags < 0 ? 0 : 1;
 463                 break;
 464         case POWER_SUPPLY_PROP_CURRENT_NOW:
 465                 ret = bq27x00_battery_current(di, val);
 466                 break;
 467         case POWER_SUPPLY_PROP_CAPACITY:
 468                 ret = bq27x00_simple_value(di->cache.capacity, val);
 469                 break;
 470         case POWER_SUPPLY_PROP_TEMP:
 471                 ret = bq27x00_battery_temperature(di, val);
 472                 break;
 473         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 474                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 475                 break;
 476         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 477                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 478                 break;
 479         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 480                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 481                 break;
 482         case POWER_SUPPLY_PROP_TECHNOLOGY:
 483                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 484                 break;
 485         case POWER_SUPPLY_PROP_CHARGE_NOW:
 486                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 487                 break;
 488         case POWER_SUPPLY_PROP_CHARGE_FULL:
 489                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 490                 break;
 491         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 492                 ret = bq27x00_simple_value(di->charge_design_full, val);
 493                 break;
 494         case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 495                 ret = bq27x00_simple_value(di->cache.charge_counter, val);
 496                 break;
 497         case POWER_SUPPLY_PROP_ENERGY_NOW:
 498                 ret = bq27x00_battery_energy(di, val);
 499                 break;
 500         default:
 501                 return -EINVAL;
 502         }
 503
 504         return ret;
 505 }
 506
 507 static void bq27x00_external_power_changed(struct power_supply *psy)
 508 {
 509         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 510
 511         cancel_delayed_work_sync(&di->work);
 512         schedule_delayed_work(&di->work, 0);
 513 }
 514
 515 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 516 {
 517         int ret;
 518
 519         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 520         di->bat.properties = bq27x00_battery_props;
 521         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 522         di->bat.get_property = bq27x00_battery_get_property;
 523         di->bat.external_power_changed = bq27x00_external_power_changed;
 524
 525         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 526         mutex_init(&di->lock);
 527
 528         ret = power_supply_register(di->dev, &di->bat);
 529         if (ret) {
 530                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 531                 return ret;
 532         }
 533
 534         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 535
 536         bq27x00_update(di);
 537
 538         return 0;
 539 }
 540
 541 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 542 {
 543         cancel_delayed_work_sync(&di->work);
 544
 545         power_supply_unregister(&di->bat);
 546
 547         mutex_destroy(&di->lock);
 548 }
 549
 550
 551 /* i2c specific code */
 552 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 553
 554 /* If the system has several batteries we need a different name for each
 555  * of them...
 556  */
 557 static DEFINE_IDR(battery_id);
 558 static DEFINE_MUTEX(battery_mutex);
 559
 560 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 561 {
 562         struct i2c_client *client = to_i2c_client(di->dev);
 563         struct i2c_msg msg[1];
 564         unsigned char data[2];
 565         int ret;
 566
 567         if (!client->adapter)
 568                 return -ENODEV;
 569
 570         msg->addr = client->addr;
 571         msg->flags = 0;
 572         msg->len = 1;
 573         msg->buf = data;
 574
 575         data[0] = reg;
 576         ret = i2c_transfer(client->adapter, msg, 1);
 577
 578         if (ret >= 0) {
 579                 if (!single)
 580                         msg->len = 2;
 581                 else
 582                         msg->len = 1;
 583
 584                 msg->flags = I2C_M_RD;
 585                 ret = i2c_transfer(client->adapter, msg, 1);
 586                 if (ret >= 0) {
 587                         if (!single)
 588                                 ret = get_unaligned_le16(data);
 589                         else
 590                                 ret = data[0];
 591                 }
 592         }
 593         return ret;
 594 }
 595
 596 static int bq27x00_battery_probe(struct i2c_client *client,
 597                                  const struct i2c_device_id *id)
 598 {
 599         char *name;
 600         struct bq27x00_device_info *di;
 601         int num;
 602         int retval = 0;
 603
 604         /* Get new ID for the new battery device */
 605         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 606         if (retval == 0)
 607                 return -ENOMEM;
 608         mutex_lock(&battery_mutex);
 609         retval = idr_get_new(&battery_id, client, &num);
 610         mutex_unlock(&battery_mutex);
 611         if (retval < 0)
 612                 return retval;
 613
 614         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 615         if (!name) {
 616                 dev_err(&client->dev, "failed to allocate device name\n");
 617                 retval = -ENOMEM;
 618                 goto batt_failed_1;
 619         }
 620
 621         di = kzalloc(sizeof(*di), GFP_KERNEL);
 622         if (!di) {
 623                 dev_err(&client->dev, "failed to allocate device info data\n");
 624                 retval = -ENOMEM;
 625                 goto batt_failed_2;
 626         }
 627
 628         di->id = num;
 629         di->dev = &client->dev;
 630         di->chip = id->driver_data;
 631         di->bat.name = name;
 632         di->bus.read = &bq27x00_read_i2c;
 633
 634         if (bq27x00_powersupply_init(di))
 635                 goto batt_failed_3;
 636
 637         i2c_set_clientdata(client, di);
 638
 639         return 0;
 640
 641 batt_failed_3:
 642         kfree(di);
 643 batt_failed_2:
 644         kfree(name);
 645 batt_failed_1:
 646         mutex_lock(&battery_mutex);
 647         idr_remove(&battery_id, num);
 648         mutex_unlock(&battery_mutex);
 649
 650         return retval;
 651 }
 652
 653 static int bq27x00_battery_remove(struct i2c_client *client)
 654 {
 655         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 656
 657         bq27x00_powersupply_unregister(di);
 658
 659         kfree(di->bat.name);
 660
 661         mutex_lock(&battery_mutex);
 662         idr_remove(&battery_id, di->id);
 663         mutex_unlock(&battery_mutex);
 664
 665         kfree(di);
 666
 667         return 0;
 668 }
 669
 670 static const struct i2c_device_id bq27x00_id[] = {
 671         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 672         { "bq27500", BQ27500 },
 673         {},
 674 };
 675 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 676
 677 static struct i2c_driver bq27x00_battery_driver = {
 678         .driver = {
 679                 .name = "bq27x00-battery",
 680         },
 681         .probe = bq27x00_battery_probe,
 682         .remove = bq27x00_battery_remove,
 683         .id_table = bq27x00_id,
 684 };
 685
 686 static inline int bq27x00_battery_i2c_init(void)
 687 {
 688         int ret = i2c_add_driver(&bq27x00_battery_driver);
 689         if (ret)
 690                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 691
 692         return ret;
 693 }
 694
 695 static inline void bq27x00_battery_i2c_exit(void)
 696 {
 697         i2c_del_driver(&bq27x00_battery_driver);
 698 }
 699
 700 #else
 701
 702 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 703 static inline void bq27x00_battery_i2c_exit(void) {};
 704
 705 #endif
 706
 707 /* platform specific code */
 708 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 709
 710 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 711                         bool single)
 712 {
 713         struct device *dev = di->dev;
 714         struct bq27000_platform_data *pdata = dev->platform_data;
 715         unsigned int timeout = 3;
 716         int upper, lower;
 717         int temp;
 718
 719         if (!single) {
 720                 /* Make sure the value has not changed in between reading the
 721                  * lower and the upper part */
 722                 upper = pdata->read(dev, reg + 1);
 723                 do {
 724                         temp = upper;
 725                         if (upper < 0)
 726                                 return upper;
 727
 728                         lower = pdata->read(dev, reg);
 729                         if (lower < 0)
 730                                 return lower;
 731
 732                         upper = pdata->read(dev, reg + 1);
 733                 } while (temp != upper && --timeout);
 734
 735                 if (timeout == 0)
 736                         return -EIO;
 737
 738                 return (upper << 8) | lower;
 739         }
 740
 741         return pdata->read(dev, reg);
 742 }
 743
 744 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 745 {
 746         struct bq27x00_device_info *di;
 747         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 748         int ret;
 749
 750         if (!pdata) {
 751                 dev_err(&pdev->dev, "no platform_data supplied\n");
 752                 return -EINVAL;
 753         }
 754
 755         if (!pdata->read) {
 756                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 757                 return -EINVAL;
 758         }
 759
 760         di = kzalloc(sizeof(*di), GFP_KERNEL);
 761         if (!di) {
 762                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 763                 return -ENOMEM;
 764         }
 765
 766         platform_set_drvdata(pdev, di);
 767
 768         di->dev = &pdev->dev;
 769         di->chip = BQ27000;
 770
 771         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 772         di->bus.read = &bq27000_read_platform;
 773
 774         ret = bq27x00_powersupply_init(di);
 775         if (ret)
 776                 goto err_free;
 777
 778         return 0;
 779
 780 err_free:
 781         platform_set_drvdata(pdev, NULL);
 782         kfree(di);
 783
 784         return ret;
 785 }
 786
 787 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 788 {
 789         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 790
 791         bq27x00_powersupply_unregister(di);
 792
 793         platform_set_drvdata(pdev, NULL);
 794         kfree(di);
 795
 796         return 0;
 797 }
 798
 799 static struct platform_driver bq27000_battery_driver = {
 800         .probe  = bq27000_battery_probe,
 801         .remove = __devexit_p(bq27000_battery_remove),
 802         .driver = {
 803                 .name = "bq27000-battery",
 804                 .owner = THIS_MODULE,
 805         },
 806 };
 807
 808 static inline int bq27x00_battery_platform_init(void)
 809 {
 810         int ret = platform_driver_register(&bq27000_battery_driver);
 811         if (ret)
 812                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 813
 814         return ret;
 815 }
 816
 817 static inline void bq27x00_battery_platform_exit(void)
 818 {
 819         platform_driver_unregister(&bq27000_battery_driver);
 820 }
 821
 822 #else
 823
 824 static inline int bq27x00_battery_platform_init(void) { return 0; }
 825 static inline void bq27x00_battery_platform_exit(void) {};
 826
 827 #endif
 828
 829 /*
 830  * Module stuff
 831  */
 832
 833 static int __init bq27x00_battery_init(void)
 834 {
 835         int ret;
 836
 837         ret = bq27x00_battery_i2c_init();
 838         if (ret)
 839                 return ret;
 840
 841         ret = bq27x00_battery_platform_init();
 842         if (ret)
 843                 bq27x00_battery_i2c_exit();
 844
 845         return ret;
 846 }
 847 module_init(bq27x00_battery_init);
 848
 849 static void __exit bq27x00_battery_exit(void)
 850 {
 851         bq27x00_battery_platform_exit();
 852         bq27x00_battery_i2c_exit();
 853 }
 854 module_exit(bq27x00_battery_exit);
 855
 856 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 857 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 858 MODULE_LICENSE("GPL");