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 Cycle count total
 252  * Or < 0 if something fails.
 253  */
 254 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 255 {
 256         int cyct;
 257
 258         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 259         if (cyct < 0)
 260                 dev_err(di->dev, "error reading cycle count total\n");
 261
 262         return cyct;
 263 }
 264
 265 /*
 266  * Read a time register.
 267  * Return < 0 if something fails.
 268  */
 269 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 270 {
 271         int tval;
 272
 273         tval = bq27x00_read(di, reg, false);
 274         if (tval < 0) {
 275                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 276                 return tval;
 277         }
 278
 279         if (tval == 65535)
 280                 return -ENODATA;
 281
 282         return tval * 60;
 283 }
 284
 285 static void bq27x00_update(struct bq27x00_device_info *di)
 286 {
 287         struct bq27x00_reg_cache cache = {0, };
 288         bool is_bq27500 = di->chip == BQ27500;
 289
 290         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 291         if (cache.flags >= 0) {
 292                 if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {
 293                         cache.capacity = -ENODATA;
 294                         cache.energy = -ENODATA;
 295                         cache.time_to_empty = -ENODATA;
 296                         cache.time_to_empty_avg = -ENODATA;
 297                         cache.time_to_full = -ENODATA;
 298                         cache.charge_full = -ENODATA;
 299                 } else {
 300                         cache.capacity = bq27x00_battery_read_rsoc(di);
 301                         cache.energy = bq27x00_battery_read_energy(di);
 302                         cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 303                         cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 304                         cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 305                         cache.charge_full = bq27x00_battery_read_lmd(di);
 306                 }
 307                 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 308                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 309
 310                 /* We only have to read charge design full once */
 311                 if (di->charge_design_full <= 0)
 312                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 313         }
 314
 315         if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {
 316                 di->cache = cache;
 317                 power_supply_changed(&di->bat);
 318         }
 319
 320         di->last_update = jiffies;
 321 }
 322
 323 static void bq27x00_battery_poll(struct work_struct *work)
 324 {
 325         struct bq27x00_device_info *di =
 326                 container_of(work, struct bq27x00_device_info, work.work);
 327
 328         bq27x00_update(di);
 329
 330         if (poll_interval > 0) {
 331                 /* The timer does not have to be accurate. */
 332                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 333                 schedule_delayed_work(&di->work, poll_interval * HZ);
 334         }
 335 }
 336
 337
 338 /*
 339  * Return the battery temperature in tenths of degree Celsius
 340  * Or < 0 if something fails.
 341  */
 342 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
 343         union power_supply_propval *val)
 344 {
 345         if (di->cache.temperature < 0)
 346                 return di->cache.temperature;
 347
 348         if (di->chip == BQ27500)
 349                 val->intval = di->cache.temperature - 2731;
 350         else
 351                 val->intval = ((di->cache.temperature * 5) - 5463) / 2;
 352
 353         return 0;
 354 }
 355
 356 /*
 357  * Return the battery average current in µA
 358  * Note that current can be negative signed as well
 359  * Or 0 if something fails.
 360  */
 361 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 362         union power_supply_propval *val)
 363 {
 364         int curr;
 365         int flags;
 366
 367         curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 368         if (curr < 0)
 369                 return curr;
 370
 371         if (di->chip == BQ27500) {
 372                 /* bq27500 returns signed value */
 373                 val->intval = (int)((s16)curr) * 1000;
 374         } else {
 375                 flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
 376                 if (flags & BQ27000_FLAG_CHGS) {
 377                         dev_dbg(di->dev, "negative current!\n");
 378                         curr = -curr;
 379                 }
 380
 381                 val->intval = curr * 3570 / BQ27000_RS;
 382         }
 383
 384         return 0;
 385 }
 386
 387 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 388         union power_supply_propval *val)
 389 {
 390         int status;
 391
 392         if (di->chip == BQ27500) {
 393                 if (di->cache.flags & BQ27500_FLAG_FC)
 394                         status = POWER_SUPPLY_STATUS_FULL;
 395                 else if (di->cache.flags & BQ27500_FLAG_DSC)
 396                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 397                 else
 398                         status = POWER_SUPPLY_STATUS_CHARGING;
 399         } else {
 400                 if (di->cache.flags & BQ27000_FLAG_FC)
 401                         status = POWER_SUPPLY_STATUS_FULL;
 402                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 403                         status = POWER_SUPPLY_STATUS_CHARGING;
 404                 else if (power_supply_am_i_supplied(&di->bat))
 405                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 406                 else
 407                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 408         }
 409
 410         val->intval = status;
 411
 412         return 0;
 413 }
 414
 415 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
 416         union power_supply_propval *val)
 417 {
 418         int level;
 419
 420         if (di->chip == BQ27500) {
 421                 if (di->cache.flags & BQ27500_FLAG_FC)
 422                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 423                 else if (di->cache.flags & BQ27500_FLAG_SOC1)
 424                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 425                 else if (di->cache.flags & BQ27500_FLAG_SOCF)
 426                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 427                 else
 428                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 429         } else {
 430                 if (di->cache.flags & BQ27000_FLAG_FC)
 431                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 432                 else if (di->cache.flags & BQ27000_FLAG_EDV1)
 433                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 434                 else if (di->cache.flags & BQ27000_FLAG_EDVF)
 435                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 436                 else
 437                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 438         }
 439
 440         val->intval = level;
 441
 442         return 0;
 443 }
 444
 445 /*
 446  * Return the battery Voltage in milivolts
 447  * Or < 0 if something fails.
 448  */
 449 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 450         union power_supply_propval *val)
 451 {
 452         int volt;
 453
 454         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 455         if (volt < 0)
 456                 return volt;
 457
 458         val->intval = volt * 1000;
 459
 460         return 0;
 461 }
 462
 463 static int bq27x00_simple_value(int value,
 464         union power_supply_propval *val)
 465 {
 466         if (value < 0)
 467                 return value;
 468
 469         val->intval = value;
 470
 471         return 0;
 472 }
 473
 474 #define to_bq27x00_device_info(x) container_of((x), \
 475                                 struct bq27x00_device_info, bat);
 476
 477 static int bq27x00_battery_get_property(struct power_supply *psy,
 478                                         enum power_supply_property psp,
 479                                         union power_supply_propval *val)
 480 {
 481         int ret = 0;
 482         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 483
 484         mutex_lock(&di->lock);
 485         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 486                 cancel_delayed_work_sync(&di->work);
 487                 bq27x00_battery_poll(&di->work.work);
 488         }
 489         mutex_unlock(&di->lock);
 490
 491         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 492                 return -ENODEV;
 493
 494         switch (psp) {
 495         case POWER_SUPPLY_PROP_STATUS:
 496                 ret = bq27x00_battery_status(di, val);
 497                 break;
 498         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 499                 ret = bq27x00_battery_voltage(di, val);
 500                 break;
 501         case POWER_SUPPLY_PROP_PRESENT:
 502                 val->intval = di->cache.flags < 0 ? 0 : 1;
 503                 break;
 504         case POWER_SUPPLY_PROP_CURRENT_NOW:
 505                 ret = bq27x00_battery_current(di, val);
 506                 break;
 507         case POWER_SUPPLY_PROP_CAPACITY:
 508                 ret = bq27x00_simple_value(di->cache.capacity, val);
 509                 break;
 510         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 511                 ret = bq27x00_battery_capacity_level(di, val);
 512                 break;
 513         case POWER_SUPPLY_PROP_TEMP:
 514                 ret = bq27x00_battery_temperature(di, val);
 515                 break;
 516         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 517                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 518                 break;
 519         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 520                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 521                 break;
 522         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 523                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 524                 break;
 525         case POWER_SUPPLY_PROP_TECHNOLOGY:
 526                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 527                 break;
 528         case POWER_SUPPLY_PROP_CHARGE_NOW:
 529                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 530                 break;
 531         case POWER_SUPPLY_PROP_CHARGE_FULL:
 532                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 533                 break;
 534         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 535                 ret = bq27x00_simple_value(di->charge_design_full, val);
 536                 break;
 537         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 538                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 539                 break;
 540         case POWER_SUPPLY_PROP_ENERGY_NOW:
 541                 ret = bq27x00_simple_value(di->cache.energy, val);
 542                 break;
 543         default:
 544                 return -EINVAL;
 545         }
 546
 547         return ret;
 548 }
 549
 550 static void bq27x00_external_power_changed(struct power_supply *psy)
 551 {
 552         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 553
 554         cancel_delayed_work_sync(&di->work);
 555         schedule_delayed_work(&di->work, 0);
 556 }
 557
 558 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 559 {
 560         int ret;
 561
 562         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 563         di->bat.properties = bq27x00_battery_props;
 564         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 565         di->bat.get_property = bq27x00_battery_get_property;
 566         di->bat.external_power_changed = bq27x00_external_power_changed;
 567
 568         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 569         mutex_init(&di->lock);
 570
 571         ret = power_supply_register(di->dev, &di->bat);
 572         if (ret) {
 573                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 574                 return ret;
 575         }
 576
 577         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 578
 579         bq27x00_update(di);
 580
 581         return 0;
 582 }
 583
 584 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 585 {
 586         cancel_delayed_work_sync(&di->work);
 587
 588         power_supply_unregister(&di->bat);
 589
 590         mutex_destroy(&di->lock);
 591 }
 592
 593
 594 /* i2c specific code */
 595 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 596
 597 /* If the system has several batteries we need a different name for each
 598  * of them...
 599  */
 600 static DEFINE_IDR(battery_id);
 601 static DEFINE_MUTEX(battery_mutex);
 602
 603 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 604 {
 605         struct i2c_client *client = to_i2c_client(di->dev);
 606         struct i2c_msg msg[2];
 607         unsigned char data[2];
 608         int ret;
 609
 610         if (!client->adapter)
 611                 return -ENODEV;
 612
 613         msg[0].addr = client->addr;
 614         msg[0].flags = 0;
 615         msg[0].buf = &reg;
 616         msg[0].len = sizeof(reg);
 617         msg[1].addr = client->addr;
 618         msg[1].flags = I2C_M_RD;
 619         msg[1].buf = data;
 620         if (single)
 621                 msg[1].len = 1;
 622         else
 623                 msg[1].len = 2;
 624
 625         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 626         if (ret < 0)
 627                 return ret;
 628
 629         if (!single)
 630                 ret = get_unaligned_le16(data);
 631         else
 632                 ret = data[0];
 633
 634         return ret;
 635 }
 636
 637 static int bq27x00_battery_probe(struct i2c_client *client,
 638                                  const struct i2c_device_id *id)
 639 {
 640         char *name;
 641         struct bq27x00_device_info *di;
 642         int num;
 643         int retval = 0;
 644
 645         /* Get new ID for the new battery device */
 646         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 647         if (retval == 0)
 648                 return -ENOMEM;
 649         mutex_lock(&battery_mutex);
 650         retval = idr_get_new(&battery_id, client, &num);
 651         mutex_unlock(&battery_mutex);
 652         if (retval < 0)
 653                 return retval;
 654
 655         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 656         if (!name) {
 657                 dev_err(&client->dev, "failed to allocate device name\n");
 658                 retval = -ENOMEM;
 659                 goto batt_failed_1;
 660         }
 661
 662         di = kzalloc(sizeof(*di), GFP_KERNEL);
 663         if (!di) {
 664                 dev_err(&client->dev, "failed to allocate device info data\n");
 665                 retval = -ENOMEM;
 666                 goto batt_failed_2;
 667         }
 668
 669         di->id = num;
 670         di->dev = &client->dev;
 671         di->chip = id->driver_data;
 672         di->bat.name = name;
 673         di->bus.read = &bq27x00_read_i2c;
 674
 675         if (bq27x00_powersupply_init(di))
 676                 goto batt_failed_3;
 677
 678         i2c_set_clientdata(client, di);
 679
 680         return 0;
 681
 682 batt_failed_3:
 683         kfree(di);
 684 batt_failed_2:
 685         kfree(name);
 686 batt_failed_1:
 687         mutex_lock(&battery_mutex);
 688         idr_remove(&battery_id, num);
 689         mutex_unlock(&battery_mutex);
 690
 691         return retval;
 692 }
 693
 694 static int bq27x00_battery_remove(struct i2c_client *client)
 695 {
 696         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 697
 698         bq27x00_powersupply_unregister(di);
 699
 700         kfree(di->bat.name);
 701
 702         mutex_lock(&battery_mutex);
 703         idr_remove(&battery_id, di->id);
 704         mutex_unlock(&battery_mutex);
 705
 706         kfree(di);
 707
 708         return 0;
 709 }
 710
 711 static const struct i2c_device_id bq27x00_id[] = {
 712         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 713         { "bq27500", BQ27500 },
 714         {},
 715 };
 716 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 717
 718 static struct i2c_driver bq27x00_battery_driver = {
 719         .driver = {
 720                 .name = "bq27x00-battery",
 721         },
 722         .probe = bq27x00_battery_probe,
 723         .remove = bq27x00_battery_remove,
 724         .id_table = bq27x00_id,
 725 };
 726
 727 static inline int bq27x00_battery_i2c_init(void)
 728 {
 729         int ret = i2c_add_driver(&bq27x00_battery_driver);
 730         if (ret)
 731                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 732
 733         return ret;
 734 }
 735
 736 static inline void bq27x00_battery_i2c_exit(void)
 737 {
 738         i2c_del_driver(&bq27x00_battery_driver);
 739 }
 740
 741 #else
 742
 743 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 744 static inline void bq27x00_battery_i2c_exit(void) {};
 745
 746 #endif
 747
 748 /* platform specific code */
 749 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 750
 751 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 752                         bool single)
 753 {
 754         struct device *dev = di->dev;
 755         struct bq27000_platform_data *pdata = dev->platform_data;
 756         unsigned int timeout = 3;
 757         int upper, lower;
 758         int temp;
 759
 760         if (!single) {
 761                 /* Make sure the value has not changed in between reading the
 762                  * lower and the upper part */
 763                 upper = pdata->read(dev, reg + 1);
 764                 do {
 765                         temp = upper;
 766                         if (upper < 0)
 767                                 return upper;
 768
 769                         lower = pdata->read(dev, reg);
 770                         if (lower < 0)
 771                                 return lower;
 772
 773                         upper = pdata->read(dev, reg + 1);
 774                 } while (temp != upper && --timeout);
 775
 776                 if (timeout == 0)
 777                         return -EIO;
 778
 779                 return (upper << 8) | lower;
 780         }
 781
 782         return pdata->read(dev, reg);
 783 }
 784
 785 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 786 {
 787         struct bq27x00_device_info *di;
 788         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 789         int ret;
 790
 791         if (!pdata) {
 792                 dev_err(&pdev->dev, "no platform_data supplied\n");
 793                 return -EINVAL;
 794         }
 795
 796         if (!pdata->read) {
 797                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 798                 return -EINVAL;
 799         }
 800
 801         di = kzalloc(sizeof(*di), GFP_KERNEL);
 802         if (!di) {
 803                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 804                 return -ENOMEM;
 805         }
 806
 807         platform_set_drvdata(pdev, di);
 808
 809         di->dev = &pdev->dev;
 810         di->chip = BQ27000;
 811
 812         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 813         di->bus.read = &bq27000_read_platform;
 814
 815         ret = bq27x00_powersupply_init(di);
 816         if (ret)
 817                 goto err_free;
 818
 819         return 0;
 820
 821 err_free:
 822         platform_set_drvdata(pdev, NULL);
 823         kfree(di);
 824
 825         return ret;
 826 }
 827
 828 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 829 {
 830         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 831
 832         bq27x00_powersupply_unregister(di);
 833
 834         platform_set_drvdata(pdev, NULL);
 835         kfree(di);
 836
 837         return 0;
 838 }
 839
 840 static struct platform_driver bq27000_battery_driver = {
 841         .probe  = bq27000_battery_probe,
 842         .remove = __devexit_p(bq27000_battery_remove),
 843         .driver = {
 844                 .name = "bq27000-battery",
 845                 .owner = THIS_MODULE,
 846         },
 847 };
 848
 849 static inline int bq27x00_battery_platform_init(void)
 850 {
 851         int ret = platform_driver_register(&bq27000_battery_driver);
 852         if (ret)
 853                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 854
 855         return ret;
 856 }
 857
 858 static inline void bq27x00_battery_platform_exit(void)
 859 {
 860         platform_driver_unregister(&bq27000_battery_driver);
 861 }
 862
 863 #else
 864
 865 static inline int bq27x00_battery_platform_init(void) { return 0; }
 866 static inline void bq27x00_battery_platform_exit(void) {};
 867
 868 #endif
 869
 870 /*
 871  * Module stuff
 872  */
 873
 874 static int __init bq27x00_battery_init(void)
 875 {
 876         int ret;
 877
 878         ret = bq27x00_battery_i2c_init();
 879         if (ret)
 880                 return ret;
 881
 882         ret = bq27x00_battery_platform_init();
 883         if (ret)
 884                 bq27x00_battery_i2c_exit();
 885
 886         return ret;
 887 }
 888 module_init(bq27x00_battery_init);
 889
 890 static void __exit bq27x00_battery_exit(void)
 891 {
 892         bq27x00_battery_platform_exit();
 893         bq27x00_battery_i2c_exit();
 894 }
 895 module_exit(bq27x00_battery_exit);
 896
 897 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 898 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 899 MODULE_LICENSE("GPL");