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_FC                 BIT(5)
  60 #define BQ27000_FLAG_CHGS               BIT(7) /* Charge state flag */
  61
  62 #define BQ27500_REG_SOC                 0x2C
  63 #define BQ27500_REG_DCAP                0x3C /* Design capacity */
  64 #define BQ27500_FLAG_DSC                BIT(0)
  65 #define BQ27500_FLAG_SOCF               BIT(1) /* State-of-Charge threshold final */
  66 #define BQ27500_FLAG_SOC1               BIT(2) /* State-of-Charge threshold 1 */
  67 #define BQ27500_FLAG_FC                 BIT(9)
  68
  69 #define BQ27000_RS                      20 /* Resistor sense */
  70
  71 struct bq27x00_device_info;
  72 struct bq27x00_access_methods {
  73         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  74 };
  75
  76 enum bq27x00_chip { BQ27000, BQ27500 };
  77
  78 struct bq27x00_reg_cache {
  79         int temperature;
  80         int time_to_empty;
  81         int time_to_empty_avg;
  82         int time_to_full;
  83         int charge_full;
  84         int cycle_count;
  85         int capacity;
  86         int flags;
  87 };
  88
  89 struct bq27x00_device_info {
  90         struct device           *dev;
  91         int                     id;
  92         enum bq27x00_chip       chip;
  93
  94         struct bq27x00_reg_cache cache;
  95         int charge_design_full;
  96
  97         unsigned long last_update;
  98         struct delayed_work work;
  99
 100         struct power_supply     bat;
 101
 102         struct bq27x00_access_methods bus;
 103
 104         struct mutex lock;
 105 };
 106
 107 static enum power_supply_property bq27x00_battery_props[] = {
 108         POWER_SUPPLY_PROP_STATUS,
 109         POWER_SUPPLY_PROP_PRESENT,
 110         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 111         POWER_SUPPLY_PROP_CURRENT_NOW,
 112         POWER_SUPPLY_PROP_CAPACITY,
 113         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 114         POWER_SUPPLY_PROP_TEMP,
 115         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 116         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 117         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 118         POWER_SUPPLY_PROP_TECHNOLOGY,
 119         POWER_SUPPLY_PROP_CHARGE_FULL,
 120         POWER_SUPPLY_PROP_CHARGE_NOW,
 121         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 122         POWER_SUPPLY_PROP_CYCLE_COUNT,
 123         POWER_SUPPLY_PROP_ENERGY_NOW,
 124 };
 125
 126 static unsigned int poll_interval = 360;
 127 module_param(poll_interval, uint, 0644);
 128 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 129                                 "0 disables polling");
 130
 131 /*
 132  * Common code for BQ27x00 devices
 133  */
 134
 135 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 136                 bool single)
 137 {
 138         return di->bus.read(di, reg, single);
 139 }
 140
 141 /*
 142  * Return the battery Relative State-of-Charge
 143  * Or < 0 if something fails.
 144  */
 145 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 146 {
 147         int rsoc;
 148
 149         if (di->chip == BQ27500)
 150                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 151         else
 152                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 153
 154         if (rsoc < 0)
 155                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 156
 157         return rsoc;
 158 }
 159
 160 /*
 161  * Return a battery charge value in µAh
 162  * Or < 0 if something fails.
 163  */
 164 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 165 {
 166         int charge;
 167
 168         charge = bq27x00_read(di, reg, false);
 169         if (charge < 0) {
 170                 dev_err(di->dev, "error reading nominal available capacity\n");
 171                 return charge;
 172         }
 173
 174         if (di->chip == BQ27500)
 175                 charge *= 1000;
 176         else
 177                 charge = charge * 3570 / BQ27000_RS;
 178
 179         return charge;
 180 }
 181
 182 /*
 183  * Return the battery Nominal available capaciy in µAh
 184  * Or < 0 if something fails.
 185  */
 186 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 187 {
 188         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 189 }
 190
 191 /*
 192  * Return the battery Last measured discharge in µAh
 193  * Or < 0 if something fails.
 194  */
 195 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 196 {
 197         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 198 }
 199
 200 /*
 201  * Return the battery Initial last measured discharge in µAh
 202  * Or < 0 if something fails.
 203  */
 204 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 205 {
 206         int ilmd;
 207
 208         if (di->chip == BQ27500)
 209                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 210         else
 211                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 212
 213         if (ilmd < 0) {
 214                 dev_err(di->dev, "error reading initial last measured discharge\n");
 215                 return ilmd;
 216         }
 217
 218         if (di->chip == BQ27500)
 219                 ilmd *= 1000;
 220         else
 221                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 222
 223         return ilmd;
 224 }
 225
 226 /*
 227  * Return the battery Cycle count total
 228  * Or < 0 if something fails.
 229  */
 230 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 231 {
 232         int cyct;
 233
 234         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 235         if (cyct < 0)
 236                 dev_err(di->dev, "error reading cycle count total\n");
 237
 238         return cyct;
 239 }
 240
 241 /*
 242  * Read a time register.
 243  * Return < 0 if something fails.
 244  */
 245 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 246 {
 247         int tval;
 248
 249         tval = bq27x00_read(di, reg, false);
 250         if (tval < 0) {
 251                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 252                 return tval;
 253         }
 254
 255         if (tval == 65535)
 256                 return -ENODATA;
 257
 258         return tval * 60;
 259 }
 260
 261 static void bq27x00_update(struct bq27x00_device_info *di)
 262 {
 263         struct bq27x00_reg_cache cache = {0, };
 264         bool is_bq27500 = di->chip == BQ27500;
 265
 266         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 267         if (cache.flags >= 0) {
 268                 cache.capacity = bq27x00_battery_read_rsoc(di);
 269                 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 270                 cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 271                 cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 272                 cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 273                 cache.charge_full = bq27x00_battery_read_lmd(di);
 274                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 275
 276                 /* We only have to read charge design full once */
 277                 if (di->charge_design_full <= 0)
 278                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 279         }
 280
 281         if (memcmp(&di->cache, &cache, sizeof(cache)) != 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 in µA
 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         int flags;
 332
 333         curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 334         if (curr < 0)
 335                 return curr;
 336
 337         if (di->chip == BQ27500) {
 338                 /* bq27500 returns signed value */
 339                 val->intval = (int)((s16)curr) * 1000;
 340         } else {
 341                 flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
 342                 if (flags & BQ27000_FLAG_CHGS) {
 343                         dev_dbg(di->dev, "negative current!\n");
 344                         curr = -curr;
 345                 }
 346
 347                 val->intval = curr * 3570 / BQ27000_RS;
 348         }
 349
 350         return 0;
 351 }
 352
 353 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 354         union power_supply_propval *val)
 355 {
 356         int status;
 357
 358         if (di->chip == BQ27500) {
 359                 if (di->cache.flags & BQ27500_FLAG_FC)
 360                         status = POWER_SUPPLY_STATUS_FULL;
 361                 else if (di->cache.flags & BQ27500_FLAG_DSC)
 362                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 363                 else
 364                         status = POWER_SUPPLY_STATUS_CHARGING;
 365         } else {
 366                 if (di->cache.flags & BQ27000_FLAG_FC)
 367                         status = POWER_SUPPLY_STATUS_FULL;
 368                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 369                         status = POWER_SUPPLY_STATUS_CHARGING;
 370                 else if (power_supply_am_i_supplied(&di->bat))
 371                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 372                 else
 373                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 374         }
 375
 376         val->intval = status;
 377
 378         return 0;
 379 }
 380
 381 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
 382         union power_supply_propval *val)
 383 {
 384         int level;
 385
 386         if (di->chip == BQ27500) {
 387                 if (di->cache.flags & BQ27500_FLAG_FC)
 388                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 389                 else if (di->cache.flags & BQ27500_FLAG_SOC1)
 390                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 391                 else if (di->cache.flags & BQ27500_FLAG_SOCF)
 392                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 393                 else
 394                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 395         } else {
 396                 if (di->cache.flags & BQ27000_FLAG_FC)
 397                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 398                 else if (di->cache.flags & BQ27000_FLAG_EDV1)
 399                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 400                 else if (di->cache.flags & BQ27000_FLAG_EDVF)
 401                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 402                 else
 403                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 404         }
 405
 406         val->intval = level;
 407
 408         return 0;
 409 }
 410
 411 /*
 412  * Return the battery Voltage in milivolts
 413  * Or < 0 if something fails.
 414  */
 415 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 416         union power_supply_propval *val)
 417 {
 418         int volt;
 419
 420         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 421         if (volt < 0)
 422                 return volt;
 423
 424         val->intval = volt * 1000;
 425
 426         return 0;
 427 }
 428
 429 /*
 430  * Return the battery Available energy in µWh
 431  * Or < 0 if something fails.
 432  */
 433 static int bq27x00_battery_energy(struct bq27x00_device_info *di,
 434         union power_supply_propval *val)
 435 {
 436         int ae;
 437
 438         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 439         if (ae < 0) {
 440                 dev_err(di->dev, "error reading available energy\n");
 441                 return ae;
 442         }
 443
 444         if (di->chip == BQ27500)
 445                 ae *= 1000;
 446         else
 447                 ae = ae * 29200 / BQ27000_RS;
 448
 449         val->intval = ae;
 450
 451         return 0;
 452 }
 453
 454
 455 static int bq27x00_simple_value(int value,
 456         union power_supply_propval *val)
 457 {
 458         if (value < 0)
 459                 return value;
 460
 461         val->intval = value;
 462
 463         return 0;
 464 }
 465
 466 #define to_bq27x00_device_info(x) container_of((x), \
 467                                 struct bq27x00_device_info, bat);
 468
 469 static int bq27x00_battery_get_property(struct power_supply *psy,
 470                                         enum power_supply_property psp,
 471                                         union power_supply_propval *val)
 472 {
 473         int ret = 0;
 474         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 475
 476         mutex_lock(&di->lock);
 477         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 478                 cancel_delayed_work_sync(&di->work);
 479                 bq27x00_battery_poll(&di->work.work);
 480         }
 481         mutex_unlock(&di->lock);
 482
 483         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 484                 return -ENODEV;
 485
 486         switch (psp) {
 487         case POWER_SUPPLY_PROP_STATUS:
 488                 ret = bq27x00_battery_status(di, val);
 489                 break;
 490         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 491                 ret = bq27x00_battery_voltage(di, val);
 492                 break;
 493         case POWER_SUPPLY_PROP_PRESENT:
 494                 val->intval = di->cache.flags < 0 ? 0 : 1;
 495                 break;
 496         case POWER_SUPPLY_PROP_CURRENT_NOW:
 497                 ret = bq27x00_battery_current(di, val);
 498                 break;
 499         case POWER_SUPPLY_PROP_CAPACITY:
 500                 ret = bq27x00_simple_value(di->cache.capacity, val);
 501                 break;
 502         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 503                 ret = bq27x00_battery_capacity_level(di, val);
 504                 break;
 505         case POWER_SUPPLY_PROP_TEMP:
 506                 ret = bq27x00_battery_temperature(di, val);
 507                 break;
 508         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 509                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 510                 break;
 511         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 512                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 513                 break;
 514         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 515                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 516                 break;
 517         case POWER_SUPPLY_PROP_TECHNOLOGY:
 518                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 519                 break;
 520         case POWER_SUPPLY_PROP_CHARGE_NOW:
 521                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 522                 break;
 523         case POWER_SUPPLY_PROP_CHARGE_FULL:
 524                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 525                 break;
 526         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 527                 ret = bq27x00_simple_value(di->charge_design_full, val);
 528                 break;
 529         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 530                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 531                 break;
 532         case POWER_SUPPLY_PROP_ENERGY_NOW:
 533                 ret = bq27x00_battery_energy(di, val);
 534                 break;
 535         default:
 536                 return -EINVAL;
 537         }
 538
 539         return ret;
 540 }
 541
 542 static void bq27x00_external_power_changed(struct power_supply *psy)
 543 {
 544         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 545
 546         cancel_delayed_work_sync(&di->work);
 547         schedule_delayed_work(&di->work, 0);
 548 }
 549
 550 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 551 {
 552         int ret;
 553
 554         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 555         di->bat.properties = bq27x00_battery_props;
 556         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 557         di->bat.get_property = bq27x00_battery_get_property;
 558         di->bat.external_power_changed = bq27x00_external_power_changed;
 559
 560         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 561         mutex_init(&di->lock);
 562
 563         ret = power_supply_register(di->dev, &di->bat);
 564         if (ret) {
 565                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 566                 return ret;
 567         }
 568
 569         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 570
 571         bq27x00_update(di);
 572
 573         return 0;
 574 }
 575
 576 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 577 {
 578         cancel_delayed_work_sync(&di->work);
 579
 580         power_supply_unregister(&di->bat);
 581
 582         mutex_destroy(&di->lock);
 583 }
 584
 585
 586 /* i2c specific code */
 587 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 588
 589 /* If the system has several batteries we need a different name for each
 590  * of them...
 591  */
 592 static DEFINE_IDR(battery_id);
 593 static DEFINE_MUTEX(battery_mutex);
 594
 595 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 596 {
 597         struct i2c_client *client = to_i2c_client(di->dev);
 598         struct i2c_msg msg[2];
 599         unsigned char data[2];
 600         int ret;
 601
 602         if (!client->adapter)
 603                 return -ENODEV;
 604
 605         msg[0].addr = client->addr;
 606         msg[0].flags = 0;
 607         msg[0].buf = &reg;
 608         msg[0].len = sizeof(reg);
 609         msg[1].addr = client->addr;
 610         msg[1].flags = I2C_M_RD;
 611         msg[1].buf = data;
 612         if (single)
 613                 msg[1].len = 1;
 614         else
 615                 msg[1].len = 2;
 616
 617         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 618         if (ret < 0)
 619                 return ret;
 620
 621         if (!single)
 622                 ret = get_unaligned_le16(data);
 623         else
 624                 ret = data[0];
 625
 626         return ret;
 627 }
 628
 629 static int bq27x00_battery_probe(struct i2c_client *client,
 630                                  const struct i2c_device_id *id)
 631 {
 632         char *name;
 633         struct bq27x00_device_info *di;
 634         int num;
 635         int retval = 0;
 636
 637         /* Get new ID for the new battery device */
 638         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 639         if (retval == 0)
 640                 return -ENOMEM;
 641         mutex_lock(&battery_mutex);
 642         retval = idr_get_new(&battery_id, client, &num);
 643         mutex_unlock(&battery_mutex);
 644         if (retval < 0)
 645                 return retval;
 646
 647         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 648         if (!name) {
 649                 dev_err(&client->dev, "failed to allocate device name\n");
 650                 retval = -ENOMEM;
 651                 goto batt_failed_1;
 652         }
 653
 654         di = kzalloc(sizeof(*di), GFP_KERNEL);
 655         if (!di) {
 656                 dev_err(&client->dev, "failed to allocate device info data\n");
 657                 retval = -ENOMEM;
 658                 goto batt_failed_2;
 659         }
 660
 661         di->id = num;
 662         di->dev = &client->dev;
 663         di->chip = id->driver_data;
 664         di->bat.name = name;
 665         di->bus.read = &bq27x00_read_i2c;
 666
 667         if (bq27x00_powersupply_init(di))
 668                 goto batt_failed_3;
 669
 670         i2c_set_clientdata(client, di);
 671
 672         return 0;
 673
 674 batt_failed_3:
 675         kfree(di);
 676 batt_failed_2:
 677         kfree(name);
 678 batt_failed_1:
 679         mutex_lock(&battery_mutex);
 680         idr_remove(&battery_id, num);
 681         mutex_unlock(&battery_mutex);
 682
 683         return retval;
 684 }
 685
 686 static int bq27x00_battery_remove(struct i2c_client *client)
 687 {
 688         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 689
 690         bq27x00_powersupply_unregister(di);
 691
 692         kfree(di->bat.name);
 693
 694         mutex_lock(&battery_mutex);
 695         idr_remove(&battery_id, di->id);
 696         mutex_unlock(&battery_mutex);
 697
 698         kfree(di);
 699
 700         return 0;
 701 }
 702
 703 static const struct i2c_device_id bq27x00_id[] = {
 704         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 705         { "bq27500", BQ27500 },
 706         {},
 707 };
 708 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 709
 710 static struct i2c_driver bq27x00_battery_driver = {
 711         .driver = {
 712                 .name = "bq27x00-battery",
 713         },
 714         .probe = bq27x00_battery_probe,
 715         .remove = bq27x00_battery_remove,
 716         .id_table = bq27x00_id,
 717 };
 718
 719 static inline int bq27x00_battery_i2c_init(void)
 720 {
 721         int ret = i2c_add_driver(&bq27x00_battery_driver);
 722         if (ret)
 723                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 724
 725         return ret;
 726 }
 727
 728 static inline void bq27x00_battery_i2c_exit(void)
 729 {
 730         i2c_del_driver(&bq27x00_battery_driver);
 731 }
 732
 733 #else
 734
 735 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 736 static inline void bq27x00_battery_i2c_exit(void) {};
 737
 738 #endif
 739
 740 /* platform specific code */
 741 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 742
 743 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 744                         bool single)
 745 {
 746         struct device *dev = di->dev;
 747         struct bq27000_platform_data *pdata = dev->platform_data;
 748         unsigned int timeout = 3;
 749         int upper, lower;
 750         int temp;
 751
 752         if (!single) {
 753                 /* Make sure the value has not changed in between reading the
 754                  * lower and the upper part */
 755                 upper = pdata->read(dev, reg + 1);
 756                 do {
 757                         temp = upper;
 758                         if (upper < 0)
 759                                 return upper;
 760
 761                         lower = pdata->read(dev, reg);
 762                         if (lower < 0)
 763                                 return lower;
 764
 765                         upper = pdata->read(dev, reg + 1);
 766                 } while (temp != upper && --timeout);
 767
 768                 if (timeout == 0)
 769                         return -EIO;
 770
 771                 return (upper << 8) | lower;
 772         }
 773
 774         return pdata->read(dev, reg);
 775 }
 776
 777 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 778 {
 779         struct bq27x00_device_info *di;
 780         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 781         int ret;
 782
 783         if (!pdata) {
 784                 dev_err(&pdev->dev, "no platform_data supplied\n");
 785                 return -EINVAL;
 786         }
 787
 788         if (!pdata->read) {
 789                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 790                 return -EINVAL;
 791         }
 792
 793         di = kzalloc(sizeof(*di), GFP_KERNEL);
 794         if (!di) {
 795                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 796                 return -ENOMEM;
 797         }
 798
 799         platform_set_drvdata(pdev, di);
 800
 801         di->dev = &pdev->dev;
 802         di->chip = BQ27000;
 803
 804         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 805         di->bus.read = &bq27000_read_platform;
 806
 807         ret = bq27x00_powersupply_init(di);
 808         if (ret)
 809                 goto err_free;
 810
 811         return 0;
 812
 813 err_free:
 814         platform_set_drvdata(pdev, NULL);
 815         kfree(di);
 816
 817         return ret;
 818 }
 819
 820 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 821 {
 822         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 823
 824         bq27x00_powersupply_unregister(di);
 825
 826         platform_set_drvdata(pdev, NULL);
 827         kfree(di);
 828
 829         return 0;
 830 }
 831
 832 static struct platform_driver bq27000_battery_driver = {
 833         .probe  = bq27000_battery_probe,
 834         .remove = __devexit_p(bq27000_battery_remove),
 835         .driver = {
 836                 .name = "bq27000-battery",
 837                 .owner = THIS_MODULE,
 838         },
 839 };
 840
 841 static inline int bq27x00_battery_platform_init(void)
 842 {
 843         int ret = platform_driver_register(&bq27000_battery_driver);
 844         if (ret)
 845                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 846
 847         return ret;
 848 }
 849
 850 static inline void bq27x00_battery_platform_exit(void)
 851 {
 852         platform_driver_unregister(&bq27000_battery_driver);
 853 }
 854
 855 #else
 856
 857 static inline int bq27x00_battery_platform_init(void) { return 0; }
 858 static inline void bq27x00_battery_platform_exit(void) {};
 859
 860 #endif
 861
 862 /*
 863  * Module stuff
 864  */
 865
 866 static int __init bq27x00_battery_init(void)
 867 {
 868         int ret;
 869
 870         ret = bq27x00_battery_i2c_init();
 871         if (ret)
 872                 return ret;
 873
 874         ret = bq27x00_battery_platform_init();
 875         if (ret)
 876                 bq27x00_battery_i2c_exit();
 877
 878         return ret;
 879 }
 880 module_init(bq27x00_battery_init);
 881
 882 static void __exit bq27x00_battery_exit(void)
 883 {
 884         bq27x00_battery_platform_exit();
 885         bq27x00_battery_i2c_exit();
 886 }
 887 module_exit(bq27x00_battery_exit);
 888
 889 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 890 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 891 MODULE_LICENSE("GPL");