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_CHGS               BIT(7)
  58 #define BQ27000_FLAG_FC                 BIT(5)
  59
  60 #define BQ27500_REG_SOC                 0x2C
  61 #define BQ27500_REG_DCAP                0x3C /* Design capacity */
  62 #define BQ27500_FLAG_DSC                BIT(0)
  63 #define BQ27500_FLAG_FC                 BIT(9)
  64
  65 #define BQ27000_RS                      20 /* Resistor sense */
  66
  67 struct bq27x00_device_info;
  68 struct bq27x00_access_methods {
  69         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  70 };
  71
  72 enum bq27x00_chip { BQ27000, BQ27500 };
  73
  74 struct bq27x00_reg_cache {
  75         int temperature;
  76         int time_to_empty;
  77         int time_to_empty_avg;
  78         int time_to_full;
  79         int charge_full;
  80         int cycle_count;
  81         int capacity;
  82         int flags;
  83
  84         int current_now;
  85 };
  86
  87 struct bq27x00_device_info {
  88         struct device           *dev;
  89         int                     id;
  90         enum bq27x00_chip       chip;
  91
  92         struct bq27x00_reg_cache cache;
  93         int charge_design_full;
  94
  95         unsigned long last_update;
  96         struct delayed_work work;
  97
  98         struct power_supply     bat;
  99
 100         struct bq27x00_access_methods bus;
 101
 102         struct mutex lock;
 103 };
 104
 105 static enum power_supply_property bq27x00_battery_props[] = {
 106         POWER_SUPPLY_PROP_STATUS,
 107         POWER_SUPPLY_PROP_PRESENT,
 108         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 109         POWER_SUPPLY_PROP_CURRENT_NOW,
 110         POWER_SUPPLY_PROP_CAPACITY,
 111         POWER_SUPPLY_PROP_TEMP,
 112         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 113         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 114         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 115         POWER_SUPPLY_PROP_TECHNOLOGY,
 116         POWER_SUPPLY_PROP_CHARGE_FULL,
 117         POWER_SUPPLY_PROP_CHARGE_NOW,
 118         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 119         POWER_SUPPLY_PROP_CYCLE_COUNT,
 120         POWER_SUPPLY_PROP_ENERGY_NOW,
 121 };
 122
 123 static unsigned int poll_interval = 360;
 124 module_param(poll_interval, uint, 0644);
 125 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 126                                 "0 disables polling");
 127
 128 /*
 129  * Common code for BQ27x00 devices
 130  */
 131
 132 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 133                 bool single)
 134 {
 135         return di->bus.read(di, reg, single);
 136 }
 137
 138 /*
 139  * Return the battery Relative State-of-Charge
 140  * Or < 0 if something fails.
 141  */
 142 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 143 {
 144         int rsoc;
 145
 146         if (di->chip == BQ27500)
 147                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 148         else
 149                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 150
 151         if (rsoc < 0)
 152                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 153
 154         return rsoc;
 155 }
 156
 157 /*
 158  * Return a battery charge value in µAh
 159  * Or < 0 if something fails.
 160  */
 161 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 162 {
 163         int charge;
 164
 165         charge = bq27x00_read(di, reg, false);
 166         if (charge < 0) {
 167                 dev_err(di->dev, "error reading nominal available capacity\n");
 168                 return charge;
 169         }
 170
 171         if (di->chip == BQ27500)
 172                 charge *= 1000;
 173         else
 174                 charge = charge * 3570 / BQ27000_RS;
 175
 176         return charge;
 177 }
 178
 179 /*
 180  * Return the battery Nominal available capaciy in µAh
 181  * Or < 0 if something fails.
 182  */
 183 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 184 {
 185         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 186 }
 187
 188 /*
 189  * Return the battery Last measured discharge in µAh
 190  * Or < 0 if something fails.
 191  */
 192 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 193 {
 194         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 195 }
 196
 197 /*
 198  * Return the battery Initial last measured discharge in µAh
 199  * Or < 0 if something fails.
 200  */
 201 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 202 {
 203         int ilmd;
 204
 205         if (di->chip == BQ27500)
 206                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 207         else
 208                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 209
 210         if (ilmd < 0) {
 211                 dev_err(di->dev, "error reading initial last measured discharge\n");
 212                 return ilmd;
 213         }
 214
 215         if (di->chip == BQ27500)
 216                 ilmd *= 1000;
 217         else
 218                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 219
 220         return ilmd;
 221 }
 222
 223 /*
 224  * Return the battery Cycle count total
 225  * Or < 0 if something fails.
 226  */
 227 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 228 {
 229         int cyct;
 230
 231         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 232         if (cyct < 0)
 233                 dev_err(di->dev, "error reading cycle count total\n");
 234
 235         return cyct;
 236 }
 237
 238 /*
 239  * Read a time register.
 240  * Return < 0 if something fails.
 241  */
 242 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 243 {
 244         int tval;
 245
 246         tval = bq27x00_read(di, reg, false);
 247         if (tval < 0) {
 248                 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
 249                 return tval;
 250         }
 251
 252         if (tval == 65535)
 253                 return -ENODATA;
 254
 255         return tval * 60;
 256 }
 257
 258 static void bq27x00_update(struct bq27x00_device_info *di)
 259 {
 260         struct bq27x00_reg_cache cache = {0, };
 261         bool is_bq27500 = di->chip == BQ27500;
 262
 263         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 264         if (cache.flags >= 0) {
 265                 cache.capacity = bq27x00_battery_read_rsoc(di);
 266                 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 267                 cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 268                 cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 269                 cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 270                 cache.charge_full = bq27x00_battery_read_lmd(di);
 271                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 272
 273                 if (!is_bq27500)
 274                         cache.current_now = bq27x00_read(di, BQ27x00_REG_AI, false);
 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         /* Ignore current_now which is a snapshot of the current battery state
 282          * and is likely to be different even between two consecutive reads */
 283         if (memcmp(&di->cache, &cache, sizeof(cache) - sizeof(int)) != 0) {
 284                 di->cache = cache;
 285                 power_supply_changed(&di->bat);
 286         }
 287
 288         di->last_update = jiffies;
 289 }
 290
 291 static void bq27x00_battery_poll(struct work_struct *work)
 292 {
 293         struct bq27x00_device_info *di =
 294                 container_of(work, struct bq27x00_device_info, work.work);
 295
 296         bq27x00_update(di);
 297
 298         if (poll_interval > 0) {
 299                 /* The timer does not have to be accurate. */
 300                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 301                 schedule_delayed_work(&di->work, poll_interval * HZ);
 302         }
 303 }
 304
 305
 306 /*
 307  * Return the battery temperature in tenths of degree Celsius
 308  * Or < 0 if something fails.
 309  */
 310 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
 311         union power_supply_propval *val)
 312 {
 313         if (di->cache.temperature < 0)
 314                 return di->cache.temperature;
 315
 316         if (di->chip == BQ27500)
 317                 val->intval = di->cache.temperature - 2731;
 318         else
 319                 val->intval = ((di->cache.temperature * 5) - 5463) / 2;
 320
 321         return 0;
 322 }
 323
 324 /*
 325  * Return the battery average current in µA
 326  * Note that current can be negative signed as well
 327  * Or 0 if something fails.
 328  */
 329 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 330         union power_supply_propval *val)
 331 {
 332         int curr;
 333
 334         if (di->chip == BQ27500)
 335             curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 336         else
 337             curr = di->cache.current_now;
 338
 339         if (curr < 0)
 340                 return curr;
 341
 342         if (di->chip == BQ27500) {
 343                 /* bq27500 returns signed value */
 344                 val->intval = (int)((s16)curr) * 1000;
 345         } else {
 346                 if (di->cache.flags & BQ27000_FLAG_CHGS) {
 347                         dev_dbg(di->dev, "negative current!\n");
 348                         curr = -curr;
 349                 }
 350
 351                 val->intval = curr * 3570 / BQ27000_RS;
 352         }
 353
 354         return 0;
 355 }
 356
 357 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 358         union power_supply_propval *val)
 359 {
 360         int status;
 361
 362         if (di->chip == BQ27500) {
 363                 if (di->cache.flags & BQ27500_FLAG_FC)
 364                         status = POWER_SUPPLY_STATUS_FULL;
 365                 else if (di->cache.flags & BQ27500_FLAG_DSC)
 366                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 367                 else
 368                         status = POWER_SUPPLY_STATUS_CHARGING;
 369         } else {
 370                 if (di->cache.flags & BQ27000_FLAG_FC)
 371                         status = POWER_SUPPLY_STATUS_FULL;
 372                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 373                         status = POWER_SUPPLY_STATUS_CHARGING;
 374                 else if (power_supply_am_i_supplied(&di->bat))
 375                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 376                 else
 377                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 378         }
 379
 380         val->intval = status;
 381
 382         return 0;
 383 }
 384
 385 /*
 386  * Return the battery Voltage in milivolts
 387  * Or < 0 if something fails.
 388  */
 389 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 390         union power_supply_propval *val)
 391 {
 392         int volt;
 393
 394         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 395         if (volt < 0)
 396                 return volt;
 397
 398         val->intval = volt * 1000;
 399
 400         return 0;
 401 }
 402
 403 /*
 404  * Return the battery Available energy in µWh
 405  * Or < 0 if something fails.
 406  */
 407 static int bq27x00_battery_energy(struct bq27x00_device_info *di,
 408         union power_supply_propval *val)
 409 {
 410         int ae;
 411
 412         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 413         if (ae < 0) {
 414                 dev_err(di->dev, "error reading available energy\n");
 415                 return ae;
 416         }
 417
 418         if (di->chip == BQ27500)
 419                 ae *= 1000;
 420         else
 421                 ae = ae * 29200 / BQ27000_RS;
 422
 423         val->intval = ae;
 424
 425         return 0;
 426 }
 427
 428
 429 static int bq27x00_simple_value(int value,
 430         union power_supply_propval *val)
 431 {
 432         if (value < 0)
 433                 return value;
 434
 435         val->intval = value;
 436
 437         return 0;
 438 }
 439
 440 #define to_bq27x00_device_info(x) container_of((x), \
 441                                 struct bq27x00_device_info, bat);
 442
 443 static int bq27x00_battery_get_property(struct power_supply *psy,
 444                                         enum power_supply_property psp,
 445                                         union power_supply_propval *val)
 446 {
 447         int ret = 0;
 448         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 449
 450         mutex_lock(&di->lock);
 451         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 452                 cancel_delayed_work_sync(&di->work);
 453                 bq27x00_battery_poll(&di->work.work);
 454         }
 455         mutex_unlock(&di->lock);
 456
 457         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 458                 return -ENODEV;
 459
 460         switch (psp) {
 461         case POWER_SUPPLY_PROP_STATUS:
 462                 ret = bq27x00_battery_status(di, val);
 463                 break;
 464         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 465                 ret = bq27x00_battery_voltage(di, val);
 466                 break;
 467         case POWER_SUPPLY_PROP_PRESENT:
 468                 val->intval = di->cache.flags < 0 ? 0 : 1;
 469                 break;
 470         case POWER_SUPPLY_PROP_CURRENT_NOW:
 471                 ret = bq27x00_battery_current(di, val);
 472                 break;
 473         case POWER_SUPPLY_PROP_CAPACITY:
 474                 ret = bq27x00_simple_value(di->cache.capacity, val);
 475                 break;
 476         case POWER_SUPPLY_PROP_TEMP:
 477                 ret = bq27x00_battery_temperature(di, val);
 478                 break;
 479         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 480                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 481                 break;
 482         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 483                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 484                 break;
 485         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 486                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 487                 break;
 488         case POWER_SUPPLY_PROP_TECHNOLOGY:
 489                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 490                 break;
 491         case POWER_SUPPLY_PROP_CHARGE_NOW:
 492                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 493                 break;
 494         case POWER_SUPPLY_PROP_CHARGE_FULL:
 495                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 496                 break;
 497         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 498                 ret = bq27x00_simple_value(di->charge_design_full, val);
 499                 break;
 500         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 501                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 502                 break;
 503         case POWER_SUPPLY_PROP_ENERGY_NOW:
 504                 ret = bq27x00_battery_energy(di, val);
 505                 break;
 506         default:
 507                 return -EINVAL;
 508         }
 509
 510         return ret;
 511 }
 512
 513 static void bq27x00_external_power_changed(struct power_supply *psy)
 514 {
 515         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 516
 517         cancel_delayed_work_sync(&di->work);
 518         schedule_delayed_work(&di->work, 0);
 519 }
 520
 521 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 522 {
 523         int ret;
 524
 525         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 526         di->bat.properties = bq27x00_battery_props;
 527         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 528         di->bat.get_property = bq27x00_battery_get_property;
 529         di->bat.external_power_changed = bq27x00_external_power_changed;
 530
 531         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 532         mutex_init(&di->lock);
 533
 534         ret = power_supply_register(di->dev, &di->bat);
 535         if (ret) {
 536                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 537                 return ret;
 538         }
 539
 540         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 541
 542         bq27x00_update(di);
 543
 544         return 0;
 545 }
 546
 547 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 548 {
 549         cancel_delayed_work_sync(&di->work);
 550
 551         power_supply_unregister(&di->bat);
 552
 553         mutex_destroy(&di->lock);
 554 }
 555
 556
 557 /* i2c specific code */
 558 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 559
 560 /* If the system has several batteries we need a different name for each
 561  * of them...
 562  */
 563 static DEFINE_IDR(battery_id);
 564 static DEFINE_MUTEX(battery_mutex);
 565
 566 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 567 {
 568         struct i2c_client *client = to_i2c_client(di->dev);
 569         struct i2c_msg msg[2];
 570         unsigned char data[2];
 571         int ret;
 572
 573         if (!client->adapter)
 574                 return -ENODEV;
 575
 576         msg[0].addr = client->addr;
 577         msg[0].flags = 0;
 578         msg[0].buf = &reg;
 579         msg[0].len = sizeof(reg);
 580         msg[1].addr = client->addr;
 581         msg[1].flags = I2C_M_RD;
 582         msg[1].buf = data;
 583         if (single)
 584                 msg[1].len = 1;
 585         else
 586                 msg[1].len = 2;
 587
 588         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 589         if (ret < 0)
 590                 return ret;
 591
 592         if (!single)
 593                 ret = get_unaligned_le16(data);
 594         else
 595                 ret = data[0];
 596
 597         return ret;
 598 }
 599
 600 static int bq27x00_battery_probe(struct i2c_client *client,
 601                                  const struct i2c_device_id *id)
 602 {
 603         char *name;
 604         struct bq27x00_device_info *di;
 605         int num;
 606         int retval = 0;
 607
 608         /* Get new ID for the new battery device */
 609         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 610         if (retval == 0)
 611                 return -ENOMEM;
 612         mutex_lock(&battery_mutex);
 613         retval = idr_get_new(&battery_id, client, &num);
 614         mutex_unlock(&battery_mutex);
 615         if (retval < 0)
 616                 return retval;
 617
 618         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 619         if (!name) {
 620                 dev_err(&client->dev, "failed to allocate device name\n");
 621                 retval = -ENOMEM;
 622                 goto batt_failed_1;
 623         }
 624
 625         di = kzalloc(sizeof(*di), GFP_KERNEL);
 626         if (!di) {
 627                 dev_err(&client->dev, "failed to allocate device info data\n");
 628                 retval = -ENOMEM;
 629                 goto batt_failed_2;
 630         }
 631
 632         di->id = num;
 633         di->dev = &client->dev;
 634         di->chip = id->driver_data;
 635         di->bat.name = name;
 636         di->bus.read = &bq27x00_read_i2c;
 637
 638         if (bq27x00_powersupply_init(di))
 639                 goto batt_failed_3;
 640
 641         i2c_set_clientdata(client, di);
 642
 643         return 0;
 644
 645 batt_failed_3:
 646         kfree(di);
 647 batt_failed_2:
 648         kfree(name);
 649 batt_failed_1:
 650         mutex_lock(&battery_mutex);
 651         idr_remove(&battery_id, num);
 652         mutex_unlock(&battery_mutex);
 653
 654         return retval;
 655 }
 656
 657 static int bq27x00_battery_remove(struct i2c_client *client)
 658 {
 659         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 660
 661         bq27x00_powersupply_unregister(di);
 662
 663         kfree(di->bat.name);
 664
 665         mutex_lock(&battery_mutex);
 666         idr_remove(&battery_id, di->id);
 667         mutex_unlock(&battery_mutex);
 668
 669         kfree(di);
 670
 671         return 0;
 672 }
 673
 674 static const struct i2c_device_id bq27x00_id[] = {
 675         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 676         { "bq27500", BQ27500 },
 677         {},
 678 };
 679 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 680
 681 static struct i2c_driver bq27x00_battery_driver = {
 682         .driver = {
 683                 .name = "bq27x00-battery",
 684         },
 685         .probe = bq27x00_battery_probe,
 686         .remove = bq27x00_battery_remove,
 687         .id_table = bq27x00_id,
 688 };
 689
 690 static inline int bq27x00_battery_i2c_init(void)
 691 {
 692         int ret = i2c_add_driver(&bq27x00_battery_driver);
 693         if (ret)
 694                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 695
 696         return ret;
 697 }
 698
 699 static inline void bq27x00_battery_i2c_exit(void)
 700 {
 701         i2c_del_driver(&bq27x00_battery_driver);
 702 }
 703
 704 #else
 705
 706 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 707 static inline void bq27x00_battery_i2c_exit(void) {};
 708
 709 #endif
 710
 711 /* platform specific code */
 712 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 713
 714 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 715                         bool single)
 716 {
 717         struct device *dev = di->dev;
 718         struct bq27000_platform_data *pdata = dev->platform_data;
 719         unsigned int timeout = 3;
 720         int upper, lower;
 721         int temp;
 722
 723         if (!single) {
 724                 /* Make sure the value has not changed in between reading the
 725                  * lower and the upper part */
 726                 upper = pdata->read(dev, reg + 1);
 727                 do {
 728                         temp = upper;
 729                         if (upper < 0)
 730                                 return upper;
 731
 732                         lower = pdata->read(dev, reg);
 733                         if (lower < 0)
 734                                 return lower;
 735
 736                         upper = pdata->read(dev, reg + 1);
 737                 } while (temp != upper && --timeout);
 738
 739                 if (timeout == 0)
 740                         return -EIO;
 741
 742                 return (upper << 8) | lower;
 743         }
 744
 745         return pdata->read(dev, reg);
 746 }
 747
 748 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 749 {
 750         struct bq27x00_device_info *di;
 751         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 752         int ret;
 753
 754         if (!pdata) {
 755                 dev_err(&pdev->dev, "no platform_data supplied\n");
 756                 return -EINVAL;
 757         }
 758
 759         if (!pdata->read) {
 760                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 761                 return -EINVAL;
 762         }
 763
 764         di = kzalloc(sizeof(*di), GFP_KERNEL);
 765         if (!di) {
 766                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 767                 return -ENOMEM;
 768         }
 769
 770         platform_set_drvdata(pdev, di);
 771
 772         di->dev = &pdev->dev;
 773         di->chip = BQ27000;
 774
 775         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 776         di->bus.read = &bq27000_read_platform;
 777
 778         ret = bq27x00_powersupply_init(di);
 779         if (ret)
 780                 goto err_free;
 781
 782         return 0;
 783
 784 err_free:
 785         platform_set_drvdata(pdev, NULL);
 786         kfree(di);
 787
 788         return ret;
 789 }
 790
 791 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 792 {
 793         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 794
 795         bq27x00_powersupply_unregister(di);
 796
 797         platform_set_drvdata(pdev, NULL);
 798         kfree(di);
 799
 800         return 0;
 801 }
 802
 803 static struct platform_driver bq27000_battery_driver = {
 804         .probe  = bq27000_battery_probe,
 805         .remove = __devexit_p(bq27000_battery_remove),
 806         .driver = {
 807                 .name = "bq27000-battery",
 808                 .owner = THIS_MODULE,
 809         },
 810 };
 811
 812 static inline int bq27x00_battery_platform_init(void)
 813 {
 814         int ret = platform_driver_register(&bq27000_battery_driver);
 815         if (ret)
 816                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 817
 818         return ret;
 819 }
 820
 821 static inline void bq27x00_battery_platform_exit(void)
 822 {
 823         platform_driver_unregister(&bq27000_battery_driver);
 824 }
 825
 826 #else
 827
 828 static inline int bq27x00_battery_platform_init(void) { return 0; }
 829 static inline void bq27x00_battery_platform_exit(void) {};
 830
 831 #endif
 832
 833 /*
 834  * Module stuff
 835  */
 836
 837 static int __init bq27x00_battery_init(void)
 838 {
 839         int ret;
 840
 841         ret = bq27x00_battery_i2c_init();
 842         if (ret)
 843                 return ret;
 844
 845         ret = bq27x00_battery_platform_init();
 846         if (ret)
 847                 bq27x00_battery_i2c_exit();
 848
 849         return ret;
 850 }
 851 module_init(bq27x00_battery_init);
 852
 853 static void __exit bq27x00_battery_exit(void)
 854 {
 855         bq27x00_battery_platform_exit();
 856         bq27x00_battery_i2c_exit();
 857 }
 858 module_exit(bq27x00_battery_exit);
 859
 860 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 861 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 862 MODULE_LICENSE("GPL");