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_DSG                BIT(0) /* Discharging */
  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_CHG                BIT(8) /* Charging */
  69 #define BQ27500_FLAG_FC                 BIT(9) /* Fully charged */
  70
  71 #define BQ27000_RS                      20 /* Resistor sense */
  72
  73 struct bq27x00_device_info;
  74 struct bq27x00_access_methods {
  75         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  76 };
  77
  78 enum bq27x00_chip { BQ27000, BQ27500 };
  79
  80 struct bq27x00_reg_cache {
  81         int temperature;
  82         int time_to_empty;
  83         int time_to_empty_avg;
  84         int time_to_full;
  85         int charge_full;
  86         int cycle_count;
  87         int capacity;
  88         int energy;
  89         int flags;
  90 };
  91
  92 struct bq27x00_device_info {
  93         struct device           *dev;
  94         int                     id;
  95         enum bq27x00_chip       chip;
  96
  97         struct bq27x00_reg_cache cache;
  98         int charge_design_full;
  99
 100         unsigned long last_update;
 101         struct delayed_work work;
 102
 103         struct power_supply     bat;
 104
 105         struct bq27x00_access_methods bus;
 106
 107         struct mutex lock;
 108 };
 109
 110 static enum power_supply_property bq27x00_battery_props[] = {
 111         POWER_SUPPLY_PROP_STATUS,
 112         POWER_SUPPLY_PROP_PRESENT,
 113         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 114         POWER_SUPPLY_PROP_CURRENT_NOW,
 115         POWER_SUPPLY_PROP_CAPACITY,
 116         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 117         POWER_SUPPLY_PROP_TEMP,
 118         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 119         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 120         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 121         POWER_SUPPLY_PROP_TECHNOLOGY,
 122         POWER_SUPPLY_PROP_CHARGE_FULL,
 123         POWER_SUPPLY_PROP_CHARGE_NOW,
 124         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 125         POWER_SUPPLY_PROP_CYCLE_COUNT,
 126         POWER_SUPPLY_PROP_ENERGY_NOW,
 127 };
 128
 129 static unsigned int poll_interval = 360;
 130 module_param(poll_interval, uint, 0644);
 131 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 132                                 "0 disables polling");
 133
 134 /*
 135  * Common code for BQ27x00 devices
 136  */
 137
 138 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 139                 bool single)
 140 {
 141         return di->bus.read(di, reg, single);
 142 }
 143
 144 /*
 145  * Return the battery Relative State-of-Charge
 146  * Or < 0 if something fails.
 147  */
 148 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 149 {
 150         int rsoc;
 151
 152         if (di->chip == BQ27500)
 153                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 154         else
 155                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 156
 157         if (rsoc < 0)
 158                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 159
 160         return rsoc;
 161 }
 162
 163 /*
 164  * Return a battery charge value in µAh
 165  * Or < 0 if something fails.
 166  */
 167 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 168 {
 169         int charge;
 170
 171         charge = bq27x00_read(di, reg, false);
 172         if (charge < 0) {
 173                 dev_err(di->dev, "error reading nominal available capacity\n");
 174                 return charge;
 175         }
 176
 177         if (di->chip == BQ27500)
 178                 charge *= 1000;
 179         else
 180                 charge = charge * 3570 / BQ27000_RS;
 181
 182         return charge;
 183 }
 184
 185 /*
 186  * Return the battery Nominal available capaciy in µAh
 187  * Or < 0 if something fails.
 188  */
 189 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 190 {
 191         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 192 }
 193
 194 /*
 195  * Return the battery Last measured discharge in µAh
 196  * Or < 0 if something fails.
 197  */
 198 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 199 {
 200         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 201 }
 202
 203 /*
 204  * Return the battery Initial last measured discharge in µAh
 205  * Or < 0 if something fails.
 206  */
 207 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 208 {
 209         int ilmd;
 210
 211         if (di->chip == BQ27500)
 212                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 213         else
 214                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 215
 216         if (ilmd < 0) {
 217                 dev_err(di->dev, "error reading initial last measured discharge\n");
 218                 return ilmd;
 219         }
 220
 221         if (di->chip == BQ27500)
 222                 ilmd *= 1000;
 223         else
 224                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 225
 226         return ilmd;
 227 }
 228
 229 /*
 230  * Return the battery Available energy in µWh
 231  * Or < 0 if something fails.
 232  */
 233 static int bq27x00_battery_read_energy(struct bq27x00_device_info *di)
 234 {
 235         int ae;
 236
 237         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 238         if (ae < 0) {
 239                 dev_err(di->dev, "error reading available energy\n");
 240                 return ae;
 241         }
 242
 243         if (di->chip == BQ27500)
 244                 ae *= 1000;
 245         else
 246                 ae = ae * 29200 / BQ27000_RS;
 247
 248         return ae;
 249 }
 250
 251 /*
 252  * Return the battery temperature in tenths of degree Celsius
 253  * Or < 0 if something fails.
 254  */
 255 static int bq27x00_battery_read_temperature(struct bq27x00_device_info *di)
 256 {
 257         int temp;
 258
 259         temp = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 260         if (temp < 0) {
 261                 dev_err(di->dev, "error reading temperature\n");
 262                 return temp;
 263         }
 264
 265         if (di->chip == BQ27500)
 266                 temp -= 2731;
 267         else
 268                 temp = ((temp * 5) - 5463) / 2;
 269
 270         return temp;
 271 }
 272
 273 /*
 274  * Return the battery Cycle count total
 275  * Or < 0 if something fails.
 276  */
 277 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 278 {
 279         int cyct;
 280
 281         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 282         if (cyct < 0)
 283                 dev_err(di->dev, "error reading cycle count total\n");
 284
 285         return cyct;
 286 }
 287
 288 /*
 289  * Read a time register.
 290  * Return < 0 if something fails.
 291  */
 292 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 293 {
 294         int tval;
 295
 296         tval = bq27x00_read(di, reg, false);
 297         if (tval < 0) {
 298                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 299                 return tval;
 300         }
 301
 302         if (tval == 65535)
 303                 return -ENODATA;
 304
 305         return tval * 60;
 306 }
 307
 308 static void bq27x00_update(struct bq27x00_device_info *di)
 309 {
 310         struct bq27x00_reg_cache cache = {0, };
 311         bool is_bq27500 = di->chip == BQ27500;
 312
 313         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 314         if (cache.flags >= 0) {
 315                 if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {
 316                         cache.capacity = -ENODATA;
 317                         cache.energy = -ENODATA;
 318                         cache.time_to_empty = -ENODATA;
 319                         cache.time_to_empty_avg = -ENODATA;
 320                         cache.time_to_full = -ENODATA;
 321                         cache.charge_full = -ENODATA;
 322                 } else {
 323                         cache.capacity = bq27x00_battery_read_rsoc(di);
 324                         cache.energy = bq27x00_battery_read_energy(di);
 325                         cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 326                         cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 327                         cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 328                         cache.charge_full = bq27x00_battery_read_lmd(di);
 329                 }
 330                 cache.temperature = bq27x00_battery_read_temperature(di);
 331                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 332
 333                 /* We only have to read charge design full once */
 334                 if (di->charge_design_full <= 0)
 335                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 336         }
 337
 338         if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {
 339                 di->cache = cache;
 340                 power_supply_changed(&di->bat);
 341         }
 342
 343         di->last_update = jiffies;
 344 }
 345
 346 static void bq27x00_battery_poll(struct work_struct *work)
 347 {
 348         struct bq27x00_device_info *di =
 349                 container_of(work, struct bq27x00_device_info, work.work);
 350
 351         bq27x00_update(di);
 352
 353         if (poll_interval > 0) {
 354                 /* The timer does not have to be accurate. */
 355                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 356                 schedule_delayed_work(&di->work, poll_interval * HZ);
 357         }
 358 }
 359
 360 /*
 361  * Return the battery average current in µA
 362  * Note that current can be negative signed as well
 363  * Or 0 if something fails.
 364  */
 365 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 366         union power_supply_propval *val)
 367 {
 368         int curr;
 369         int flags;
 370
 371         curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 372         if (curr < 0)
 373                 return curr;
 374
 375         if (di->chip == BQ27500) {
 376                 /* bq27500 returns signed value */
 377                 val->intval = (int)((s16)curr) * 1000;
 378         } else {
 379                 flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
 380                 if (flags & BQ27000_FLAG_CHGS) {
 381                         dev_dbg(di->dev, "negative current!\n");
 382                         curr = -curr;
 383                 }
 384
 385                 val->intval = curr * 3570 / BQ27000_RS;
 386         }
 387
 388         return 0;
 389 }
 390
 391 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 392         union power_supply_propval *val)
 393 {
 394         int status;
 395
 396         if (di->chip == BQ27500) {
 397                 if (di->cache.flags & BQ27500_FLAG_FC)
 398                         status = POWER_SUPPLY_STATUS_FULL;
 399                 else if (di->cache.flags & BQ27500_FLAG_DSG)
 400                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 401                 else if (di->cache.flags & BQ27500_FLAG_CHG)
 402                         status = POWER_SUPPLY_STATUS_CHARGING;
 403                 else if (power_supply_am_i_supplied(&di->bat))
 404                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 405                 else
 406                         status = POWER_SUPPLY_STATUS_UNKNOWN;
 407         } else {
 408                 if (di->cache.flags & BQ27000_FLAG_FC)
 409                         status = POWER_SUPPLY_STATUS_FULL;
 410                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 411                         status = POWER_SUPPLY_STATUS_CHARGING;
 412                 else if (power_supply_am_i_supplied(&di->bat))
 413                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 414                 else
 415                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 416         }
 417
 418         val->intval = status;
 419
 420         return 0;
 421 }
 422
 423 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
 424         union power_supply_propval *val)
 425 {
 426         int level;
 427
 428         if (di->chip == BQ27500) {
 429                 if (di->cache.flags & BQ27500_FLAG_FC)
 430                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 431                 else if (di->cache.flags & BQ27500_FLAG_SOC1)
 432                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 433                 else if (di->cache.flags & BQ27500_FLAG_SOCF)
 434                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 435                 else
 436                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 437         } else {
 438                 if (di->cache.flags & BQ27000_FLAG_FC)
 439                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 440                 else if (di->cache.flags & BQ27000_FLAG_EDV1)
 441                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 442                 else if (di->cache.flags & BQ27000_FLAG_EDVF)
 443                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 444                 else
 445                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 446         }
 447
 448         val->intval = level;
 449
 450         return 0;
 451 }
 452
 453 /*
 454  * Return the battery Voltage in milivolts
 455  * Or < 0 if something fails.
 456  */
 457 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 458         union power_supply_propval *val)
 459 {
 460         int volt;
 461
 462         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 463         if (volt < 0)
 464                 return volt;
 465
 466         val->intval = volt * 1000;
 467
 468         return 0;
 469 }
 470
 471 static int bq27x00_simple_value(int value,
 472         union power_supply_propval *val)
 473 {
 474         if (value < 0)
 475                 return value;
 476
 477         val->intval = value;
 478
 479         return 0;
 480 }
 481
 482 #define to_bq27x00_device_info(x) container_of((x), \
 483                                 struct bq27x00_device_info, bat);
 484
 485 static int bq27x00_battery_get_property(struct power_supply *psy,
 486                                         enum power_supply_property psp,
 487                                         union power_supply_propval *val)
 488 {
 489         int ret = 0;
 490         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 491
 492         mutex_lock(&di->lock);
 493         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 494                 cancel_delayed_work_sync(&di->work);
 495                 bq27x00_battery_poll(&di->work.work);
 496         }
 497         mutex_unlock(&di->lock);
 498
 499         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 500                 return -ENODEV;
 501
 502         switch (psp) {
 503         case POWER_SUPPLY_PROP_STATUS:
 504                 ret = bq27x00_battery_status(di, val);
 505                 break;
 506         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 507                 ret = bq27x00_battery_voltage(di, val);
 508                 break;
 509         case POWER_SUPPLY_PROP_PRESENT:
 510                 val->intval = di->cache.flags < 0 ? 0 : 1;
 511                 break;
 512         case POWER_SUPPLY_PROP_CURRENT_NOW:
 513                 ret = bq27x00_battery_current(di, val);
 514                 break;
 515         case POWER_SUPPLY_PROP_CAPACITY:
 516                 ret = bq27x00_simple_value(di->cache.capacity, val);
 517                 break;
 518         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 519                 ret = bq27x00_battery_capacity_level(di, val);
 520                 break;
 521         case POWER_SUPPLY_PROP_TEMP:
 522                 ret = bq27x00_simple_value(di->cache.temperature, val);
 523                 break;
 524         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 525                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 526                 break;
 527         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 528                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 529                 break;
 530         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 531                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 532                 break;
 533         case POWER_SUPPLY_PROP_TECHNOLOGY:
 534                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 535                 break;
 536         case POWER_SUPPLY_PROP_CHARGE_NOW:
 537                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 538                 break;
 539         case POWER_SUPPLY_PROP_CHARGE_FULL:
 540                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 541                 break;
 542         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 543                 ret = bq27x00_simple_value(di->charge_design_full, val);
 544                 break;
 545         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 546                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 547                 break;
 548         case POWER_SUPPLY_PROP_ENERGY_NOW:
 549                 ret = bq27x00_simple_value(di->cache.energy, val);
 550                 break;
 551         default:
 552                 return -EINVAL;
 553         }
 554
 555         return ret;
 556 }
 557
 558 static void bq27x00_external_power_changed(struct power_supply *psy)
 559 {
 560         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 561
 562         cancel_delayed_work_sync(&di->work);
 563         schedule_delayed_work(&di->work, 0);
 564 }
 565
 566 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 567 {
 568         int ret;
 569
 570         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 571         di->bat.properties = bq27x00_battery_props;
 572         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 573         di->bat.get_property = bq27x00_battery_get_property;
 574         di->bat.external_power_changed = bq27x00_external_power_changed;
 575
 576         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 577         mutex_init(&di->lock);
 578
 579         ret = power_supply_register(di->dev, &di->bat);
 580         if (ret) {
 581                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 582                 return ret;
 583         }
 584
 585         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 586
 587         bq27x00_update(di);
 588
 589         return 0;
 590 }
 591
 592 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 593 {
 594         cancel_delayed_work_sync(&di->work);
 595
 596         power_supply_unregister(&di->bat);
 597
 598         mutex_destroy(&di->lock);
 599 }
 600
 601
 602 /* i2c specific code */
 603 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 604
 605 /* If the system has several batteries we need a different name for each
 606  * of them...
 607  */
 608 static DEFINE_IDR(battery_id);
 609 static DEFINE_MUTEX(battery_mutex);
 610
 611 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 612 {
 613         struct i2c_client *client = to_i2c_client(di->dev);
 614         struct i2c_msg msg[2];
 615         unsigned char data[2];
 616         int ret;
 617
 618         if (!client->adapter)
 619                 return -ENODEV;
 620
 621         msg[0].addr = client->addr;
 622         msg[0].flags = 0;
 623         msg[0].buf = &reg;
 624         msg[0].len = sizeof(reg);
 625         msg[1].addr = client->addr;
 626         msg[1].flags = I2C_M_RD;
 627         msg[1].buf = data;
 628         if (single)
 629                 msg[1].len = 1;
 630         else
 631                 msg[1].len = 2;
 632
 633         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 634         if (ret < 0)
 635                 return ret;
 636
 637         if (!single)
 638                 ret = get_unaligned_le16(data);
 639         else
 640                 ret = data[0];
 641
 642         return ret;
 643 }
 644
 645 static int bq27x00_battery_probe(struct i2c_client *client,
 646                                  const struct i2c_device_id *id)
 647 {
 648         char *name;
 649         struct bq27x00_device_info *di;
 650         int num;
 651         int retval = 0;
 652
 653         /* Get new ID for the new battery device */
 654         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 655         if (retval == 0)
 656                 return -ENOMEM;
 657         mutex_lock(&battery_mutex);
 658         retval = idr_get_new(&battery_id, client, &num);
 659         mutex_unlock(&battery_mutex);
 660         if (retval < 0)
 661                 return retval;
 662
 663         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 664         if (!name) {
 665                 dev_err(&client->dev, "failed to allocate device name\n");
 666                 retval = -ENOMEM;
 667                 goto batt_failed_1;
 668         }
 669
 670         di = kzalloc(sizeof(*di), GFP_KERNEL);
 671         if (!di) {
 672                 dev_err(&client->dev, "failed to allocate device info data\n");
 673                 retval = -ENOMEM;
 674                 goto batt_failed_2;
 675         }
 676
 677         di->id = num;
 678         di->dev = &client->dev;
 679         di->chip = id->driver_data;
 680         di->bat.name = name;
 681         di->bus.read = &bq27x00_read_i2c;
 682
 683         if (bq27x00_powersupply_init(di))
 684                 goto batt_failed_3;
 685
 686         i2c_set_clientdata(client, di);
 687
 688         return 0;
 689
 690 batt_failed_3:
 691         kfree(di);
 692 batt_failed_2:
 693         kfree(name);
 694 batt_failed_1:
 695         mutex_lock(&battery_mutex);
 696         idr_remove(&battery_id, num);
 697         mutex_unlock(&battery_mutex);
 698
 699         return retval;
 700 }
 701
 702 static int bq27x00_battery_remove(struct i2c_client *client)
 703 {
 704         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 705
 706         bq27x00_powersupply_unregister(di);
 707
 708         kfree(di->bat.name);
 709
 710         mutex_lock(&battery_mutex);
 711         idr_remove(&battery_id, di->id);
 712         mutex_unlock(&battery_mutex);
 713
 714         kfree(di);
 715
 716         return 0;
 717 }
 718
 719 static const struct i2c_device_id bq27x00_id[] = {
 720         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 721         { "bq27500", BQ27500 },
 722         {},
 723 };
 724 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 725
 726 static struct i2c_driver bq27x00_battery_driver = {
 727         .driver = {
 728                 .name = "bq27x00-battery",
 729         },
 730         .probe = bq27x00_battery_probe,
 731         .remove = bq27x00_battery_remove,
 732         .id_table = bq27x00_id,
 733 };
 734
 735 static inline int bq27x00_battery_i2c_init(void)
 736 {
 737         int ret = i2c_add_driver(&bq27x00_battery_driver);
 738         if (ret)
 739                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 740
 741         return ret;
 742 }
 743
 744 static inline void bq27x00_battery_i2c_exit(void)
 745 {
 746         i2c_del_driver(&bq27x00_battery_driver);
 747 }
 748
 749 #else
 750
 751 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 752 static inline void bq27x00_battery_i2c_exit(void) {};
 753
 754 #endif
 755
 756 /* platform specific code */
 757 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 758
 759 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 760                         bool single)
 761 {
 762         struct device *dev = di->dev;
 763         struct bq27000_platform_data *pdata = dev->platform_data;
 764         unsigned int timeout = 3;
 765         int upper, lower;
 766         int temp;
 767
 768         if (!single) {
 769                 /* Make sure the value has not changed in between reading the
 770                  * lower and the upper part */
 771                 upper = pdata->read(dev, reg + 1);
 772                 do {
 773                         temp = upper;
 774                         if (upper < 0)
 775                                 return upper;
 776
 777                         lower = pdata->read(dev, reg);
 778                         if (lower < 0)
 779                                 return lower;
 780
 781                         upper = pdata->read(dev, reg + 1);
 782                 } while (temp != upper && --timeout);
 783
 784                 if (timeout == 0)
 785                         return -EIO;
 786
 787                 return (upper << 8) | lower;
 788         }
 789
 790         return pdata->read(dev, reg);
 791 }
 792
 793 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 794 {
 795         struct bq27x00_device_info *di;
 796         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 797         int ret;
 798
 799         if (!pdata) {
 800                 dev_err(&pdev->dev, "no platform_data supplied\n");
 801                 return -EINVAL;
 802         }
 803
 804         if (!pdata->read) {
 805                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 806                 return -EINVAL;
 807         }
 808
 809         di = kzalloc(sizeof(*di), GFP_KERNEL);
 810         if (!di) {
 811                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 812                 return -ENOMEM;
 813         }
 814
 815         platform_set_drvdata(pdev, di);
 816
 817         di->dev = &pdev->dev;
 818         di->chip = BQ27000;
 819
 820         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 821         di->bus.read = &bq27000_read_platform;
 822
 823         ret = bq27x00_powersupply_init(di);
 824         if (ret)
 825                 goto err_free;
 826
 827         return 0;
 828
 829 err_free:
 830         platform_set_drvdata(pdev, NULL);
 831         kfree(di);
 832
 833         return ret;
 834 }
 835
 836 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 837 {
 838         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 839
 840         bq27x00_powersupply_unregister(di);
 841
 842         platform_set_drvdata(pdev, NULL);
 843         kfree(di);
 844
 845         return 0;
 846 }
 847
 848 static struct platform_driver bq27000_battery_driver = {
 849         .probe  = bq27000_battery_probe,
 850         .remove = __devexit_p(bq27000_battery_remove),
 851         .driver = {
 852                 .name = "bq27000-battery",
 853                 .owner = THIS_MODULE,
 854         },
 855 };
 856
 857 static inline int bq27x00_battery_platform_init(void)
 858 {
 859         int ret = platform_driver_register(&bq27000_battery_driver);
 860         if (ret)
 861                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 862
 863         return ret;
 864 }
 865
 866 static inline void bq27x00_battery_platform_exit(void)
 867 {
 868         platform_driver_unregister(&bq27000_battery_driver);
 869 }
 870
 871 #else
 872
 873 static inline int bq27x00_battery_platform_init(void) { return 0; }
 874 static inline void bq27x00_battery_platform_exit(void) {};
 875
 876 #endif
 877
 878 /*
 879  * Module stuff
 880  */
 881
 882 static int __init bq27x00_battery_init(void)
 883 {
 884         int ret;
 885
 886         ret = bq27x00_battery_i2c_init();
 887         if (ret)
 888                 return ret;
 889
 890         ret = bq27x00_battery_platform_init();
 891         if (ret)
 892                 bq27x00_battery_i2c_exit();
 893
 894         return ret;
 895 }
 896 module_init(bq27x00_battery_init);
 897
 898 static void __exit bq27x00_battery_exit(void)
 899 {
 900         bq27x00_battery_platform_exit();
 901         bq27x00_battery_i2c_exit();
 902 }
 903 module_exit(bq27x00_battery_exit);
 904
 905 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 906 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 907 MODULE_LICENSE("GPL");