Pileus Git - ~andy/linux/blob - 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  * Copyright (C) 2011 Pali Rohár <pali.rohar@gmail.com>
   8  *
   9  * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
  10  *
  11  * This package is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  */
  20
  21 /*
  22  * Datasheets:
  23  * http://focus.ti.com/docs/prod/folders/print/bq27000.html
  24  * http://focus.ti.com/docs/prod/folders/print/bq27500.html
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/param.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/delay.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/power_supply.h>
  34 #include <linux/idr.h>
  35 #include <linux/i2c.h>
  36 #include <linux/slab.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <linux/power/bq27x00_battery.h>
  40
  41 #define DRIVER_VERSION                  "1.2.0"
  42
  43 #define BQ27x00_REG_TEMP                0x06
  44 #define BQ27x00_REG_VOLT                0x08
  45 #define BQ27x00_REG_AI                  0x14
  46 #define BQ27x00_REG_FLAGS               0x0A
  47 #define BQ27x00_REG_TTE                 0x16
  48 #define BQ27x00_REG_TTF                 0x18
  49 #define BQ27x00_REG_TTECP               0x26
  50 #define BQ27x00_REG_NAC                 0x0C /* Nominal available capaciy */
  51 #define BQ27x00_REG_LMD                 0x12 /* Last measured discharge */
  52 #define BQ27x00_REG_CYCT                0x2A /* Cycle count total */
  53 #define BQ27x00_REG_AE                  0x22 /* Available enery */
  54
  55 #define BQ27000_REG_RSOC                0x0B /* Relative State-of-Charge */
  56 #define BQ27000_REG_ILMD                0x76 /* Initial last measured discharge */
  57 #define BQ27000_FLAG_EDVF               BIT(0) /* Final End-of-Discharge-Voltage flag */
  58 #define BQ27000_FLAG_EDV1               BIT(1) /* First End-of-Discharge-Voltage flag */
  59 #define BQ27000_FLAG_CI                 BIT(4) /* Capacity Inaccurate flag */
  60 #define BQ27000_FLAG_FC                 BIT(5)
  61 #define BQ27000_FLAG_CHGS               BIT(7) /* Charge state flag */
  62
  63 #define BQ27500_REG_SOC                 0x2C
  64 #define BQ27500_REG_DCAP                0x3C /* Design capacity */
  65 #define BQ27500_FLAG_DSC                BIT(0)
  66 #define BQ27500_FLAG_SOCF               BIT(1) /* State-of-Charge threshold final */
  67 #define BQ27500_FLAG_SOC1               BIT(2) /* State-of-Charge threshold 1 */
  68 #define BQ27500_FLAG_FC                 BIT(9)
  69
  70 #define BQ27000_RS                      20 /* Resistor sense */
  71
  72 struct bq27x00_device_info;
  73 struct bq27x00_access_methods {
  74         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  75 };
  76
  77 enum bq27x00_chip { BQ27000, BQ27500 };
  78
  79 struct bq27x00_reg_cache {
  80         int temperature;
  81         int time_to_empty;
  82         int time_to_empty_avg;
  83         int time_to_full;
  84         int charge_full;
  85         int cycle_count;
  86         int capacity;
  87         int energy;
  88         int flags;
  89 };
  90
  91 struct bq27x00_device_info {
  92         struct device           *dev;
  93         int                     id;
  94         enum bq27x00_chip       chip;
  95
  96         struct bq27x00_reg_cache cache;
  97         int charge_design_full;
  98
  99         unsigned long last_update;
 100         struct delayed_work work;
 101
 102         struct power_supply     bat;
 103
 104         struct bq27x00_access_methods bus;
 105
 106         struct mutex lock;
 107 };
 108
 109 static enum power_supply_property bq27x00_battery_props[] = {
 110         POWER_SUPPLY_PROP_STATUS,
 111         POWER_SUPPLY_PROP_PRESENT,
 112         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 113         POWER_SUPPLY_PROP_CURRENT_NOW,
 114         POWER_SUPPLY_PROP_CAPACITY,
 115         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 116         POWER_SUPPLY_PROP_TEMP,
 117         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 118         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 119         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 120         POWER_SUPPLY_PROP_TECHNOLOGY,
 121         POWER_SUPPLY_PROP_CHARGE_FULL,
 122         POWER_SUPPLY_PROP_CHARGE_NOW,
 123         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 124         POWER_SUPPLY_PROP_CYCLE_COUNT,
 125         POWER_SUPPLY_PROP_ENERGY_NOW,
 126 };
 127
 128 static unsigned int poll_interval = 360;
 129 module_param(poll_interval, uint, 0644);
 130 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 131                                 "0 disables polling");
 132
 133 /*
 134  * Common code for BQ27x00 devices
 135  */
 136
 137 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 138                 bool single)
 139 {
 140         return di->bus.read(di, reg, single);
 141 }
 142
 143 /*
 144  * Return the battery Relative State-of-Charge
 145  * Or < 0 if something fails.
 146  */
 147 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 148 {
 149         int rsoc;
 150
 151         if (di->chip == BQ27500)
 152                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 153         else
 154                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 155
 156         if (rsoc < 0)
 157                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 158
 159         return rsoc;
 160 }
 161
 162 /*
 163  * Return a battery charge value in µAh
 164  * Or < 0 if something fails.
 165  */
 166 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 167 {
 168         int charge;
 169
 170         charge = bq27x00_read(di, reg, false);
 171         if (charge < 0) {
 172                 dev_err(di->dev, "error reading nominal available capacity\n");
 173                 return charge;
 174         }
 175
 176         if (di->chip == BQ27500)
 177                 charge *= 1000;
 178         else
 179                 charge = charge * 3570 / BQ27000_RS;
 180
 181         return charge;
 182 }
 183
 184 /*
 185  * Return the battery Nominal available capaciy in µAh
 186  * Or < 0 if something fails.
 187  */
 188 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 189 {
 190         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 191 }
 192
 193 /*
 194  * Return the battery Last measured discharge in µAh
 195  * Or < 0 if something fails.
 196  */
 197 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 198 {
 199         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 200 }
 201
 202 /*
 203  * Return the battery Initial last measured discharge in µAh
 204  * Or < 0 if something fails.
 205  */
 206 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 207 {
 208         int ilmd;
 209
 210         if (di->chip == BQ27500)
 211                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 212         else
 213                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 214
 215         if (ilmd < 0) {
 216                 dev_err(di->dev, "error reading initial last measured discharge\n");
 217                 return ilmd;
 218         }
 219
 220         if (di->chip == BQ27500)
 221                 ilmd *= 1000;
 222         else
 223                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 224
 225         return ilmd;
 226 }
 227
 228 /*
 229  * Return the battery Available energy in µWh
 230  * Or < 0 if something fails.
 231  */
 232 static int bq27x00_battery_read_energy(struct bq27x00_device_info *di)
 233 {
 234         int ae;
 235
 236         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 237         if (ae < 0) {
 238                 dev_err(di->dev, "error reading available energy\n");
 239                 return ae;
 240         }
 241
 242         if (di->chip == BQ27500)
 243                 ae *= 1000;
 244         else
 245                 ae = ae * 29200 / BQ27000_RS;
 246
 247         return ae;
 248 }
 249
 250 /*
 251  * Return the battery temperature in tenths of degree Celsius
 252  * Or < 0 if something fails.
 253  */
 254 static int bq27x00_battery_read_temperature(struct bq27x00_device_info *di)
 255 {
 256         int temp;
 257
 258         temp = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 259         if (temp < 0) {
 260                 dev_err(di->dev, "error reading temperature\n");
 261                 return temp;
 262         }
 263
 264         if (di->chip == BQ27500)
 265                 temp -= 2731;
 266         else
 267                 temp = ((temp * 5) - 5463) / 2;
 268
 269         return temp;
 270 }
 271
 272 /*
 273  * Return the battery Cycle count total
 274  * Or < 0 if something fails.
 275  */
 276 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 277 {
 278         int cyct;
 279
 280         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 281         if (cyct < 0)
 282                 dev_err(di->dev, "error reading cycle count total\n");
 283
 284         return cyct;
 285 }
 286
 287 /*
 288  * Read a time register.
 289  * Return < 0 if something fails.
 290  */
 291 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 292 {
 293         int tval;
 294
 295         tval = bq27x00_read(di, reg, false);
 296         if (tval < 0) {
 297                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 298                 return tval;
 299         }
 300
 301         if (tval == 65535)
 302                 return -ENODATA;
 303
 304         return tval * 60;
 305 }
 306
 307 static void bq27x00_update(struct bq27x00_device_info *di)
 308 {
 309         struct bq27x00_reg_cache cache = {0, };
 310         bool is_bq27500 = di->chip == BQ27500;
 311
 312         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 313         if (cache.flags >= 0) {
 314                 if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {
 315                         cache.capacity = -ENODATA;
 316                         cache.energy = -ENODATA;
 317                         cache.time_to_empty = -ENODATA;
 318                         cache.time_to_empty_avg = -ENODATA;
 319                         cache.time_to_full = -ENODATA;
 320                         cache.charge_full = -ENODATA;
 321                 } else {
 322                         cache.capacity = bq27x00_battery_read_rsoc(di);
 323                         cache.energy = bq27x00_battery_read_energy(di);
 324                         cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 325                         cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 326                         cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 327                         cache.charge_full = bq27x00_battery_read_lmd(di);
 328                 }
 329                 cache.temperature = bq27x00_battery_read_temperature(di);
 330                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 331
 332                 /* We only have to read charge design full once */
 333                 if (di->charge_design_full <= 0)
 334                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 335         }
 336
 337         if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {
 338                 di->cache = cache;
 339                 power_supply_changed(&di->bat);
 340         }
 341
 342         di->last_update = jiffies;
 343 }
 344
 345 static void bq27x00_battery_poll(struct work_struct *work)
 346 {
 347         struct bq27x00_device_info *di =
 348                 container_of(work, struct bq27x00_device_info, work.work);
 349
 350         bq27x00_update(di);
 351
 352         if (poll_interval > 0) {
 353                 /* The timer does not have to be accurate. */
 354                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 355                 schedule_delayed_work(&di->work, poll_interval * HZ);
 356         }
 357 }
 358
 359 /*
 360  * Return the battery average current in µA
 361  * Note that current can be negative signed as well
 362  * Or 0 if something fails.
 363  */
 364 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 365         union power_supply_propval *val)
 366 {
 367         int curr;
 368         int flags;
 369
 370         curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 371         if (curr < 0)
 372                 return curr;
 373
 374         if (di->chip == BQ27500) {
 375                 /* bq27500 returns signed value */
 376                 val->intval = (int)((s16)curr) * 1000;
 377         } else {
 378                 flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
 379                 if (flags & BQ27000_FLAG_CHGS) {
 380                         dev_dbg(di->dev, "negative current!\n");
 381                         curr = -curr;
 382                 }
 383
 384                 val->intval = curr * 3570 / BQ27000_RS;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 391         union power_supply_propval *val)
 392 {
 393         int status;
 394
 395         if (di->chip == BQ27500) {
 396                 if (di->cache.flags & BQ27500_FLAG_FC)
 397                         status = POWER_SUPPLY_STATUS_FULL;
 398                 else if (di->cache.flags & BQ27500_FLAG_DSC)
 399                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 400                 else
 401                         status = POWER_SUPPLY_STATUS_CHARGING;
 402         } else {
 403                 if (di->cache.flags & BQ27000_FLAG_FC)
 404                         status = POWER_SUPPLY_STATUS_FULL;
 405                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 406                         status = POWER_SUPPLY_STATUS_CHARGING;
 407                 else if (power_supply_am_i_supplied(&di->bat))
 408                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 409                 else
 410                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 411         }
 412
 413         val->intval = status;
 414
 415         return 0;
 416 }
 417
 418 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
 419         union power_supply_propval *val)
 420 {
 421         int level;
 422
 423         if (di->chip == BQ27500) {
 424                 if (di->cache.flags & BQ27500_FLAG_FC)
 425                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 426                 else if (di->cache.flags & BQ27500_FLAG_SOC1)
 427                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 428                 else if (di->cache.flags & BQ27500_FLAG_SOCF)
 429                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 430                 else
 431                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 432         } else {
 433                 if (di->cache.flags & BQ27000_FLAG_FC)
 434                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 435                 else if (di->cache.flags & BQ27000_FLAG_EDV1)
 436                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 437                 else if (di->cache.flags & BQ27000_FLAG_EDVF)
 438                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 439                 else
 440                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 441         }
 442
 443         val->intval = level;
 444
 445         return 0;
 446 }
 447
 448 /*
 449  * Return the battery Voltage in milivolts
 450  * Or < 0 if something fails.
 451  */
 452 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 453         union power_supply_propval *val)
 454 {
 455         int volt;
 456
 457         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 458         if (volt < 0)
 459                 return volt;
 460
 461         val->intval = volt * 1000;
 462
 463         return 0;
 464 }
 465
 466 static int bq27x00_simple_value(int value,
 467         union power_supply_propval *val)
 468 {
 469         if (value < 0)
 470                 return value;
 471
 472         val->intval = value;
 473
 474         return 0;
 475 }
 476
 477 #define to_bq27x00_device_info(x) container_of((x), \
 478                                 struct bq27x00_device_info, bat);
 479
 480 static int bq27x00_battery_get_property(struct power_supply *psy,
 481                                         enum power_supply_property psp,
 482                                         union power_supply_propval *val)
 483 {
 484         int ret = 0;
 485         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 486
 487         mutex_lock(&di->lock);
 488         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 489                 cancel_delayed_work_sync(&di->work);
 490                 bq27x00_battery_poll(&di->work.work);
 491         }
 492         mutex_unlock(&di->lock);
 493
 494         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 495                 return -ENODEV;
 496
 497         switch (psp) {
 498         case POWER_SUPPLY_PROP_STATUS:
 499                 ret = bq27x00_battery_status(di, val);
 500                 break;
 501         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 502                 ret = bq27x00_battery_voltage(di, val);
 503                 break;
 504         case POWER_SUPPLY_PROP_PRESENT:
 505                 val->intval = di->cache.flags < 0 ? 0 : 1;
 506                 break;
 507         case POWER_SUPPLY_PROP_CURRENT_NOW:
 508                 ret = bq27x00_battery_current(di, val);
 509                 break;
 510         case POWER_SUPPLY_PROP_CAPACITY:
 511                 ret = bq27x00_simple_value(di->cache.capacity, val);
 512                 break;
 513         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 514                 ret = bq27x00_battery_capacity_level(di, val);
 515                 break;
 516         case POWER_SUPPLY_PROP_TEMP:
 517                 ret = bq27x00_simple_value(di->cache.temperature, val);
 518                 break;
 519         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 520                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 521                 break;
 522         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 523                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 524                 break;
 525         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 526                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 527                 break;
 528         case POWER_SUPPLY_PROP_TECHNOLOGY:
 529                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 530                 break;
 531         case POWER_SUPPLY_PROP_CHARGE_NOW:
 532                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 533                 break;
 534         case POWER_SUPPLY_PROP_CHARGE_FULL:
 535                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 536                 break;
 537         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 538                 ret = bq27x00_simple_value(di->charge_design_full, val);
 539                 break;
 540         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 541                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 542                 break;
 543         case POWER_SUPPLY_PROP_ENERGY_NOW:
 544                 ret = bq27x00_simple_value(di->cache.energy, val);
 545                 break;
 546         default:
 547                 return -EINVAL;
 548         }
 549
 550         return ret;
 551 }
 552
 553 static void bq27x00_external_power_changed(struct power_supply *psy)
 554 {
 555         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 556
 557         cancel_delayed_work_sync(&di->work);
 558         schedule_delayed_work(&di->work, 0);
 559 }
 560
 561 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 562 {
 563         int ret;
 564
 565         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 566         di->bat.properties = bq27x00_battery_props;
 567         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 568         di->bat.get_property = bq27x00_battery_get_property;
 569         di->bat.external_power_changed = bq27x00_external_power_changed;
 570
 571         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 572         mutex_init(&di->lock);
 573
 574         ret = power_supply_register(di->dev, &di->bat);
 575         if (ret) {
 576                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 577                 return ret;
 578         }
 579
 580         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 581
 582         bq27x00_update(di);
 583
 584         return 0;
 585 }
 586
 587 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 588 {
 589         cancel_delayed_work_sync(&di->work);
 590
 591         power_supply_unregister(&di->bat);
 592
 593         mutex_destroy(&di->lock);
 594 }
 595
 596
 597 /* i2c specific code */
 598 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 599
 600 /* If the system has several batteries we need a different name for each
 601  * of them...
 602  */
 603 static DEFINE_IDR(battery_id);
 604 static DEFINE_MUTEX(battery_mutex);
 605
 606 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 607 {
 608         struct i2c_client *client = to_i2c_client(di->dev);
 609         struct i2c_msg msg[2];
 610         unsigned char data[2];
 611         int ret;
 612
 613         if (!client->adapter)
 614                 return -ENODEV;
 615
 616         msg[0].addr = client->addr;
 617         msg[0].flags = 0;
 618         msg[0].buf = &reg;
 619         msg[0].len = sizeof(reg);
 620         msg[1].addr = client->addr;
 621         msg[1].flags = I2C_M_RD;
 622         msg[1].buf = data;
 623         if (single)
 624                 msg[1].len = 1;
 625         else
 626                 msg[1].len = 2;
 627
 628         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 629         if (ret < 0)
 630                 return ret;
 631
 632         if (!single)
 633                 ret = get_unaligned_le16(data);
 634         else
 635                 ret = data[0];
 636
 637         return ret;
 638 }
 639
 640 static int bq27x00_battery_probe(struct i2c_client *client,
 641                                  const struct i2c_device_id *id)
 642 {
 643         char *name;
 644         struct bq27x00_device_info *di;
 645         int num;
 646         int retval = 0;
 647
 648         /* Get new ID for the new battery device */
 649         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 650         if (retval == 0)
 651                 return -ENOMEM;
 652         mutex_lock(&battery_mutex);
 653         retval = idr_get_new(&battery_id, client, &num);
 654         mutex_unlock(&battery_mutex);
 655         if (retval < 0)
 656                 return retval;
 657
 658         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 659         if (!name) {
 660                 dev_err(&client->dev, "failed to allocate device name\n");
 661                 retval = -ENOMEM;
 662                 goto batt_failed_1;
 663         }
 664
 665         di = kzalloc(sizeof(*di), GFP_KERNEL);
 666         if (!di) {
 667                 dev_err(&client->dev, "failed to allocate device info data\n");
 668                 retval = -ENOMEM;
 669                 goto batt_failed_2;
 670         }
 671
 672         di->id = num;
 673         di->dev = &client->dev;
 674         di->chip = id->driver_data;
 675         di->bat.name = name;
 676         di->bus.read = &bq27x00_read_i2c;
 677
 678         if (bq27x00_powersupply_init(di))
 679                 goto batt_failed_3;
 680
 681         i2c_set_clientdata(client, di);
 682
 683         return 0;
 684
 685 batt_failed_3:
 686         kfree(di);
 687 batt_failed_2:
 688         kfree(name);
 689 batt_failed_1:
 690         mutex_lock(&battery_mutex);
 691         idr_remove(&battery_id, num);
 692         mutex_unlock(&battery_mutex);
 693
 694         return retval;
 695 }
 696
 697 static int bq27x00_battery_remove(struct i2c_client *client)
 698 {
 699         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 700
 701         bq27x00_powersupply_unregister(di);
 702
 703         kfree(di->bat.name);
 704
 705         mutex_lock(&battery_mutex);
 706         idr_remove(&battery_id, di->id);
 707         mutex_unlock(&battery_mutex);
 708
 709         kfree(di);
 710
 711         return 0;
 712 }
 713
 714 static const struct i2c_device_id bq27x00_id[] = {
 715         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 716         { "bq27500", BQ27500 },
 717         {},
 718 };
 719 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 720
 721 static struct i2c_driver bq27x00_battery_driver = {
 722         .driver = {
 723                 .name = "bq27x00-battery",
 724         },
 725         .probe = bq27x00_battery_probe,
 726         .remove = bq27x00_battery_remove,
 727         .id_table = bq27x00_id,
 728 };
 729
 730 static inline int bq27x00_battery_i2c_init(void)
 731 {
 732         int ret = i2c_add_driver(&bq27x00_battery_driver);
 733         if (ret)
 734                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 735
 736         return ret;
 737 }
 738
 739 static inline void bq27x00_battery_i2c_exit(void)
 740 {
 741         i2c_del_driver(&bq27x00_battery_driver);
 742 }
 743
 744 #else
 745
 746 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 747 static inline void bq27x00_battery_i2c_exit(void) {};
 748
 749 #endif
 750
 751 /* platform specific code */
 752 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 753
 754 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 755                         bool single)
 756 {
 757         struct device *dev = di->dev;
 758         struct bq27000_platform_data *pdata = dev->platform_data;
 759         unsigned int timeout = 3;
 760         int upper, lower;
 761         int temp;
 762
 763         if (!single) {
 764                 /* Make sure the value has not changed in between reading the
 765                  * lower and the upper part */
 766                 upper = pdata->read(dev, reg + 1);
 767                 do {
 768                         temp = upper;
 769                         if (upper < 0)
 770                                 return upper;
 771
 772                         lower = pdata->read(dev, reg);
 773                         if (lower < 0)
 774                                 return lower;
 775
 776                         upper = pdata->read(dev, reg + 1);
 777                 } while (temp != upper && --timeout);
 778
 779                 if (timeout == 0)
 780                         return -EIO;
 781
 782                 return (upper << 8) | lower;
 783         }
 784
 785         return pdata->read(dev, reg);
 786 }
 787
 788 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 789 {
 790         struct bq27x00_device_info *di;
 791         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 792         int ret;
 793
 794         if (!pdata) {
 795                 dev_err(&pdev->dev, "no platform_data supplied\n");
 796                 return -EINVAL;
 797         }
 798
 799         if (!pdata->read) {
 800                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 801                 return -EINVAL;
 802         }
 803
 804         di = kzalloc(sizeof(*di), GFP_KERNEL);
 805         if (!di) {
 806                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 807                 return -ENOMEM;
 808         }
 809
 810         platform_set_drvdata(pdev, di);
 811
 812         di->dev = &pdev->dev;
 813         di->chip = BQ27000;
 814
 815         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 816         di->bus.read = &bq27000_read_platform;
 817
 818         ret = bq27x00_powersupply_init(di);
 819         if (ret)
 820                 goto err_free;
 821
 822         return 0;
 823
 824 err_free:
 825         platform_set_drvdata(pdev, NULL);
 826         kfree(di);
 827
 828         return ret;
 829 }
 830
 831 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 832 {
 833         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 834
 835         bq27x00_powersupply_unregister(di);
 836
 837         platform_set_drvdata(pdev, NULL);
 838         kfree(di);
 839
 840         return 0;
 841 }
 842
 843 static struct platform_driver bq27000_battery_driver = {
 844         .probe  = bq27000_battery_probe,
 845         .remove = __devexit_p(bq27000_battery_remove),
 846         .driver = {
 847                 .name = "bq27000-battery",
 848                 .owner = THIS_MODULE,
 849         },
 850 };
 851
 852 static inline int bq27x00_battery_platform_init(void)
 853 {
 854         int ret = platform_driver_register(&bq27000_battery_driver);
 855         if (ret)
 856                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 857
 858         return ret;
 859 }
 860
 861 static inline void bq27x00_battery_platform_exit(void)
 862 {
 863         platform_driver_unregister(&bq27000_battery_driver);
 864 }
 865
 866 #else
 867
 868 static inline int bq27x00_battery_platform_init(void) { return 0; }
 869 static inline void bq27x00_battery_platform_exit(void) {};
 870
 871 #endif
 872
 873 /*
 874  * Module stuff
 875  */
 876
 877 static int __init bq27x00_battery_init(void)
 878 {
 879         int ret;
 880
 881         ret = bq27x00_battery_i2c_init();
 882         if (ret)
 883                 return ret;
 884
 885         ret = bq27x00_battery_platform_init();
 886         if (ret)
 887                 bq27x00_battery_i2c_exit();
 888
 889         return ret;
 890 }
 891 module_init(bq27x00_battery_init);
 892
 893 static void __exit bq27x00_battery_exit(void)
 894 {
 895         bq27x00_battery_platform_exit();
 896         bq27x00_battery_i2c_exit();
 897 }
 898 module_exit(bq27x00_battery_exit);
 899
 900 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 901 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 902 MODULE_LICENSE("GPL");