drivers/power/bq20z75.c

   1 /*
   2  * Gas Gauge driver for TI's BQ20Z75
   3  *
   4  * Copyright (c) 2010, NVIDIA Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/err.h>
  25 #include <linux/power_supply.h>
  26 #include <linux/i2c.h>
  27 #include <linux/slab.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/gpio.h>
  30
  31 #include <linux/power/bq20z75.h>
  32
  33 enum {
  34         REG_MANUFACTURER_DATA,
  35         REG_TEMPERATURE,
  36         REG_VOLTAGE,
  37         REG_CURRENT,
  38         REG_CAPACITY,
  39         REG_TIME_TO_EMPTY,
  40         REG_TIME_TO_FULL,
  41         REG_STATUS,
  42         REG_CYCLE_COUNT,
  43         REG_SERIAL_NUMBER,
  44         REG_REMAINING_CAPACITY,
  45         REG_REMAINING_CAPACITY_CHARGE,
  46         REG_FULL_CHARGE_CAPACITY,
  47         REG_FULL_CHARGE_CAPACITY_CHARGE,
  48         REG_DESIGN_CAPACITY,
  49         REG_DESIGN_CAPACITY_CHARGE,
  50         REG_DESIGN_VOLTAGE,
  51 };
  52
  53 /* Battery Mode defines */
  54 #define BATTERY_MODE_OFFSET             0x03
  55 #define BATTERY_MODE_MASK               0x8000
  56 enum bq20z75_battery_mode {
  57         BATTERY_MODE_AMPS,
  58         BATTERY_MODE_WATTS
  59 };
  60
  61 /* manufacturer access defines */
  62 #define MANUFACTURER_ACCESS_STATUS      0x0006
  63 #define MANUFACTURER_ACCESS_SLEEP       0x0011
  64
  65 /* battery status value bits */
  66 #define BATTERY_DISCHARGING             0x40
  67 #define BATTERY_FULL_CHARGED            0x20
  68 #define BATTERY_FULL_DISCHARGED         0x10
  69
  70 #define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
  71         .psp = _psp, \
  72         .addr = _addr, \
  73         .min_value = _min_value, \
  74         .max_value = _max_value, \
  75 }
  76
  77 static const struct bq20z75_device_data {
  78         enum power_supply_property psp;
  79         u8 addr;
  80         int min_value;
  81         int max_value;
  82 } bq20z75_data[] = {
  83         [REG_MANUFACTURER_DATA] =
  84                 BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
  85         [REG_TEMPERATURE] =
  86                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
  87         [REG_VOLTAGE] =
  88                 BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
  89         [REG_CURRENT] =
  90                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
  91                         32767),
  92         [REG_CAPACITY] =
  93                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
  94         [REG_REMAINING_CAPACITY] =
  95                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
  96         [REG_REMAINING_CAPACITY_CHARGE] =
  97                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_NOW, 0x0F, 0, 65535),
  98         [REG_FULL_CHARGE_CAPACITY] =
  99                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
 100         [REG_FULL_CHARGE_CAPACITY_CHARGE] =
 101                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL, 0x10, 0, 65535),
 102         [REG_TIME_TO_EMPTY] =
 103                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
 104                         65535),
 105         [REG_TIME_TO_FULL] =
 106                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
 107                         65535),
 108         [REG_STATUS] =
 109                 BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
 110         [REG_CYCLE_COUNT] =
 111                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
 112         [REG_DESIGN_CAPACITY] =
 113                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
 114                         65535),
 115         [REG_DESIGN_CAPACITY_CHARGE] =
 116                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 0x18, 0,
 117                         65535),
 118         [REG_DESIGN_VOLTAGE] =
 119                 BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
 120                         65535),
 121         [REG_SERIAL_NUMBER] =
 122                 BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
 123 };
 124
 125 static enum power_supply_property bq20z75_properties[] = {
 126         POWER_SUPPLY_PROP_STATUS,
 127         POWER_SUPPLY_PROP_HEALTH,
 128         POWER_SUPPLY_PROP_PRESENT,
 129         POWER_SUPPLY_PROP_TECHNOLOGY,
 130         POWER_SUPPLY_PROP_CYCLE_COUNT,
 131         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 132         POWER_SUPPLY_PROP_CURRENT_NOW,
 133         POWER_SUPPLY_PROP_CAPACITY,
 134         POWER_SUPPLY_PROP_TEMP,
 135         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 136         POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
 137         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 138         POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 139         POWER_SUPPLY_PROP_ENERGY_NOW,
 140         POWER_SUPPLY_PROP_ENERGY_FULL,
 141         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 142         POWER_SUPPLY_PROP_CHARGE_NOW,
 143         POWER_SUPPLY_PROP_CHARGE_FULL,
 144         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 145 };
 146
 147 struct bq20z75_info {
 148         struct i2c_client               *client;
 149         struct power_supply             power_supply;
 150         struct bq20z75_platform_data    *pdata;
 151         bool                            is_present;
 152         bool                            gpio_detect;
 153         bool                            enable_detection;
 154         int                             irq;
 155 };
 156
 157 static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
 158 {
 159         s32 ret;
 160
 161         ret = i2c_smbus_read_word_data(client, address);
 162         if (ret < 0) {
 163                 dev_err(&client->dev,
 164                         "%s: i2c read at address 0x%x failed\n",
 165                         __func__, address);
 166                 return ret;
 167         }
 168         return le16_to_cpu(ret);
 169 }
 170
 171 static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
 172         u16 value)
 173 {
 174         s32 ret;
 175
 176         ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
 177         if (ret < 0) {
 178                 dev_err(&client->dev,
 179                         "%s: i2c write to address 0x%x failed\n",
 180                         __func__, address);
 181                 return ret;
 182         }
 183         return 0;
 184 }
 185
 186 static int bq20z75_get_battery_presence_and_health(
 187         struct i2c_client *client, enum power_supply_property psp,
 188         union power_supply_propval *val)
 189 {
 190         s32 ret;
 191         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 192
 193         if (psp == POWER_SUPPLY_PROP_PRESENT &&
 194                 bq20z75_device->gpio_detect) {
 195                 ret = gpio_get_value(
 196                         bq20z75_device->pdata->battery_detect);
 197                 if (ret == bq20z75_device->pdata->battery_detect_present)
 198                         val->intval = 1;
 199                 else
 200                         val->intval = 0;
 201                 return ret;
 202         }
 203
 204         /* Write to ManufacturerAccess with
 205          * ManufacturerAccess command and then
 206          * read the status */
 207         ret = bq20z75_write_word_data(client,
 208                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 209                 MANUFACTURER_ACCESS_STATUS);
 210         if (ret < 0)
 211                 return ret;
 212
 213
 214         ret = bq20z75_read_word_data(client,
 215                 bq20z75_data[REG_MANUFACTURER_DATA].addr);
 216         if (ret < 0) {
 217                 if (psp == POWER_SUPPLY_PROP_PRESENT)
 218                         val->intval = 0; /* battery removed */
 219                 return ret;
 220         }
 221
 222         if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
 223             ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
 224                 val->intval = 0;
 225                 return 0;
 226         }
 227
 228         /* Mask the upper nibble of 2nd byte and
 229          * lower byte of response then
 230          * shift the result by 8 to get status*/
 231         ret &= 0x0F00;
 232         ret >>= 8;
 233         if (psp == POWER_SUPPLY_PROP_PRESENT) {
 234                 if (ret == 0x0F)
 235                         /* battery removed */
 236                         val->intval = 0;
 237                 else
 238                         val->intval = 1;
 239         } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
 240                 if (ret == 0x09)
 241                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 242                 else if (ret == 0x0B)
 243                         val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 244                 else if (ret == 0x0C)
 245                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 246                 else
 247                         val->intval = POWER_SUPPLY_HEALTH_GOOD;
 248         }
 249
 250         return 0;
 251 }
 252
 253 static int bq20z75_get_battery_property(struct i2c_client *client,
 254         int reg_offset, enum power_supply_property psp,
 255         union power_supply_propval *val)
 256 {
 257         s32 ret;
 258
 259         ret = bq20z75_read_word_data(client,
 260                 bq20z75_data[reg_offset].addr);
 261         if (ret < 0)
 262                 return ret;
 263
 264         /* returned values are 16 bit */
 265         if (bq20z75_data[reg_offset].min_value < 0)
 266                 ret = (s16)ret;
 267
 268         if (ret >= bq20z75_data[reg_offset].min_value &&
 269             ret <= bq20z75_data[reg_offset].max_value) {
 270                 val->intval = ret;
 271                 if (psp == POWER_SUPPLY_PROP_STATUS) {
 272                         if (ret & BATTERY_FULL_CHARGED)
 273                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 274                         else if (ret & BATTERY_FULL_DISCHARGED)
 275                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 276                         else if (ret & BATTERY_DISCHARGING)
 277                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 278                         else
 279                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 280                 }
 281         } else {
 282                 if (psp == POWER_SUPPLY_PROP_STATUS)
 283                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 284                 else
 285                         val->intval = 0;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static void  bq20z75_unit_adjustment(struct i2c_client *client,
 292         enum power_supply_property psp, union power_supply_propval *val)
 293 {
 294 #define BASE_UNIT_CONVERSION            1000
 295 #define BATTERY_MODE_CAP_MULT_WATT      (10 * BASE_UNIT_CONVERSION)
 296 #define TIME_UNIT_CONVERSION            600
 297 #define TEMP_KELVIN_TO_CELCIUS          2731
 298         switch (psp) {
 299         case POWER_SUPPLY_PROP_ENERGY_NOW:
 300         case POWER_SUPPLY_PROP_ENERGY_FULL:
 301         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 302                 val->intval *= BATTERY_MODE_CAP_MULT_WATT;
 303                 break;
 304
 305         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 306         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 307         case POWER_SUPPLY_PROP_CURRENT_NOW:
 308         case POWER_SUPPLY_PROP_CHARGE_NOW:
 309         case POWER_SUPPLY_PROP_CHARGE_FULL:
 310         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 311                 val->intval *= BASE_UNIT_CONVERSION;
 312                 break;
 313
 314         case POWER_SUPPLY_PROP_TEMP:
 315                 /* bq20z75 provides battery tempreture in 0.1°K
 316                  * so convert it to 0.1°C */
 317                 val->intval -= TEMP_KELVIN_TO_CELCIUS;
 318                 val->intval *= 10;
 319                 break;
 320
 321         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 322         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 323                 val->intval *= TIME_UNIT_CONVERSION;
 324                 break;
 325
 326         default:
 327                 dev_dbg(&client->dev,
 328                         "%s: no need for unit conversion %d\n", __func__, psp);
 329         }
 330 }
 331
 332 static enum bq20z75_battery_mode
 333 bq20z75_set_battery_mode(struct i2c_client *client,
 334         enum bq20z75_battery_mode mode)
 335 {
 336         int ret, original_val;
 337
 338         original_val = bq20z75_read_word_data(client, BATTERY_MODE_OFFSET);
 339         if (original_val < 0)
 340                 return original_val;
 341
 342         if ((original_val & BATTERY_MODE_MASK) == mode)
 343                 return mode;
 344
 345         if (mode == BATTERY_MODE_AMPS)
 346                 ret = original_val & ~BATTERY_MODE_MASK;
 347         else
 348                 ret = original_val | BATTERY_MODE_MASK;
 349
 350         ret = bq20z75_write_word_data(client, BATTERY_MODE_OFFSET, ret);
 351         if (ret < 0)
 352                 return ret;
 353
 354         return original_val & BATTERY_MODE_MASK;
 355 }
 356
 357 static int bq20z75_get_battery_capacity(struct i2c_client *client,
 358         int reg_offset, enum power_supply_property psp,
 359         union power_supply_propval *val)
 360 {
 361         s32 ret;
 362         enum bq20z75_battery_mode mode = BATTERY_MODE_WATTS;
 363
 364         if (power_supply_is_amp_property(psp))
 365                 mode = BATTERY_MODE_AMPS;
 366
 367         mode = bq20z75_set_battery_mode(client, mode);
 368         if (mode < 0)
 369                 return mode;
 370
 371         ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
 372         if (ret < 0)
 373                 return ret;
 374
 375         if (psp == POWER_SUPPLY_PROP_CAPACITY) {
 376                 /* bq20z75 spec says that this can be >100 %
 377                 * even if max value is 100 % */
 378                 val->intval = min(ret, 100);
 379         } else
 380                 val->intval = ret;
 381
 382         ret = bq20z75_set_battery_mode(client, mode);
 383         if (ret < 0)
 384                 return ret;
 385
 386         return 0;
 387 }
 388
 389 static char bq20z75_serial[5];
 390 static int bq20z75_get_battery_serial_number(struct i2c_client *client,
 391         union power_supply_propval *val)
 392 {
 393         int ret;
 394
 395         ret = bq20z75_read_word_data(client,
 396                 bq20z75_data[REG_SERIAL_NUMBER].addr);
 397         if (ret < 0)
 398                 return ret;
 399
 400         ret = sprintf(bq20z75_serial, "%04x", ret);
 401         val->strval = bq20z75_serial;
 402
 403         return 0;
 404 }
 405
 406 static int bq20z75_get_property_index(struct i2c_client *client,
 407         enum power_supply_property psp)
 408 {
 409         int count;
 410         for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
 411                 if (psp == bq20z75_data[count].psp)
 412                         return count;
 413
 414         dev_warn(&client->dev,
 415                 "%s: Invalid Property - %d\n", __func__, psp);
 416
 417         return -EINVAL;
 418 }
 419
 420 static int bq20z75_get_property(struct power_supply *psy,
 421         enum power_supply_property psp,
 422         union power_supply_propval *val)
 423 {
 424         int ret = 0;
 425         struct bq20z75_info *bq20z75_device = container_of(psy,
 426                                 struct bq20z75_info, power_supply);
 427         struct i2c_client *client = bq20z75_device->client;
 428
 429         switch (psp) {
 430         case POWER_SUPPLY_PROP_PRESENT:
 431         case POWER_SUPPLY_PROP_HEALTH:
 432                 ret = bq20z75_get_battery_presence_and_health(client, psp, val);
 433                 break;
 434
 435         case POWER_SUPPLY_PROP_TECHNOLOGY:
 436                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 437                 break;
 438
 439         case POWER_SUPPLY_PROP_ENERGY_NOW:
 440         case POWER_SUPPLY_PROP_ENERGY_FULL:
 441         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 442         case POWER_SUPPLY_PROP_CHARGE_NOW:
 443         case POWER_SUPPLY_PROP_CHARGE_FULL:
 444         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 445         case POWER_SUPPLY_PROP_CAPACITY:
 446                 ret = bq20z75_get_property_index(client, psp);
 447                 if (ret < 0)
 448                         break;
 449
 450                 ret = bq20z75_get_battery_capacity(client, ret, psp, val);
 451                 break;
 452
 453         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 454                 ret = bq20z75_get_battery_serial_number(client, val);
 455                 break;
 456
 457         case POWER_SUPPLY_PROP_STATUS:
 458         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 459         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 460         case POWER_SUPPLY_PROP_CURRENT_NOW:
 461         case POWER_SUPPLY_PROP_TEMP:
 462         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 463         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 464         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 465                 ret = bq20z75_get_property_index(client, psp);
 466                 if (ret < 0)
 467                         break;
 468
 469                 ret = bq20z75_get_battery_property(client, ret, psp, val);
 470                 break;
 471
 472         default:
 473                 dev_err(&client->dev,
 474                         "%s: INVALID property\n", __func__);
 475                 return -EINVAL;
 476         }
 477
 478         if (!bq20z75_device->enable_detection)
 479                 goto done;
 480
 481         if (!bq20z75_device->gpio_detect &&
 482                 bq20z75_device->is_present != (ret >= 0)) {
 483                 bq20z75_device->is_present = (ret >= 0);
 484                 power_supply_changed(&bq20z75_device->power_supply);
 485         }
 486
 487 done:
 488         if (!ret) {
 489                 /* Convert units to match requirements for power supply class */
 490                 bq20z75_unit_adjustment(client, psp, val);
 491         }
 492
 493         dev_dbg(&client->dev,
 494                 "%s: property = %d, value = %d\n", __func__, psp, val->intval);
 495
 496         return ret;
 497 }
 498
 499 static irqreturn_t bq20z75_irq(int irq, void *devid)
 500 {
 501         struct power_supply *battery = devid;
 502
 503         power_supply_changed(battery);
 504
 505         return IRQ_HANDLED;
 506 }
 507
 508 static int __devinit bq20z75_probe(struct i2c_client *client,
 509         const struct i2c_device_id *id)
 510 {
 511         struct bq20z75_info *bq20z75_device;
 512         struct bq20z75_platform_data *pdata = client->dev.platform_data;
 513         int rc;
 514         int irq;
 515
 516         bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
 517         if (!bq20z75_device)
 518                 return -ENOMEM;
 519
 520         bq20z75_device->client = client;
 521         bq20z75_device->enable_detection = false;
 522         bq20z75_device->gpio_detect = false;
 523         bq20z75_device->power_supply.name = "battery";
 524         bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
 525         bq20z75_device->power_supply.properties = bq20z75_properties;
 526         bq20z75_device->power_supply.num_properties =
 527                 ARRAY_SIZE(bq20z75_properties);
 528         bq20z75_device->power_supply.get_property = bq20z75_get_property;
 529
 530         if (pdata) {
 531                 bq20z75_device->gpio_detect =
 532                         gpio_is_valid(pdata->battery_detect);
 533                 bq20z75_device->pdata = pdata;
 534         }
 535
 536         i2c_set_clientdata(client, bq20z75_device);
 537
 538         if (!bq20z75_device->gpio_detect)
 539                 goto skip_gpio;
 540
 541         rc = gpio_request(pdata->battery_detect, dev_name(&client->dev));
 542         if (rc) {
 543                 dev_warn(&client->dev, "Failed to request gpio: %d\n", rc);
 544                 bq20z75_device->gpio_detect = false;
 545                 goto skip_gpio;
 546         }
 547
 548         rc = gpio_direction_input(pdata->battery_detect);
 549         if (rc) {
 550                 dev_warn(&client->dev, "Failed to get gpio as input: %d\n", rc);
 551                 gpio_free(pdata->battery_detect);
 552                 bq20z75_device->gpio_detect = false;
 553                 goto skip_gpio;
 554         }
 555
 556         irq = gpio_to_irq(pdata->battery_detect);
 557         if (irq <= 0) {
 558                 dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
 559                 gpio_free(pdata->battery_detect);
 560                 bq20z75_device->gpio_detect = false;
 561                 goto skip_gpio;
 562         }
 563
 564         rc = request_irq(irq, bq20z75_irq,
 565                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 566                 dev_name(&client->dev), &bq20z75_device->power_supply);
 567         if (rc) {
 568                 dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
 569                 gpio_free(pdata->battery_detect);
 570                 bq20z75_device->gpio_detect = false;
 571                 goto skip_gpio;
 572         }
 573
 574         bq20z75_device->irq = irq;
 575
 576 skip_gpio:
 577
 578         rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
 579         if (rc) {
 580                 dev_err(&client->dev,
 581                         "%s: Failed to register power supply\n", __func__);
 582                 goto exit_psupply;
 583         }
 584
 585         dev_info(&client->dev,
 586                 "%s: battery gas gauge device registered\n", client->name);
 587
 588         return 0;
 589
 590 exit_psupply:
 591         if (bq20z75_device->irq)
 592                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 593         if (bq20z75_device->gpio_detect)
 594                 gpio_free(pdata->battery_detect);
 595
 596         kfree(bq20z75_device);
 597
 598         return rc;
 599 }
 600
 601 static int __devexit bq20z75_remove(struct i2c_client *client)
 602 {
 603         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 604
 605         if (bq20z75_device->irq)
 606                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 607         if (bq20z75_device->gpio_detect)
 608                 gpio_free(bq20z75_device->pdata->battery_detect);
 609
 610         power_supply_unregister(&bq20z75_device->power_supply);
 611         kfree(bq20z75_device);
 612         bq20z75_device = NULL;
 613
 614         return 0;
 615 }
 616
 617 #if defined CONFIG_PM
 618 static int bq20z75_suspend(struct i2c_client *client,
 619         pm_message_t state)
 620 {
 621         s32 ret;
 622
 623         /* write to manufacturer access with sleep command */
 624         ret = bq20z75_write_word_data(client,
 625                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 626                 MANUFACTURER_ACCESS_SLEEP);
 627         if (ret < 0)
 628                 return ret;
 629
 630         return 0;
 631 }
 632 #else
 633 #define bq20z75_suspend         NULL
 634 #endif
 635 /* any smbus transaction will wake up bq20z75 */
 636 #define bq20z75_resume          NULL
 637
 638 static const struct i2c_device_id bq20z75_id[] = {
 639         { "bq20z75", 0 },
 640         {}
 641 };
 642
 643 static struct i2c_driver bq20z75_battery_driver = {
 644         .probe          = bq20z75_probe,
 645         .remove         = __devexit_p(bq20z75_remove),
 646         .suspend        = bq20z75_suspend,
 647         .resume         = bq20z75_resume,
 648         .id_table       = bq20z75_id,
 649         .driver = {
 650                 .name   = "bq20z75-battery",
 651         },
 652 };
 653
 654 static int __init bq20z75_battery_init(void)
 655 {
 656         return i2c_add_driver(&bq20z75_battery_driver);
 657 }
 658 module_init(bq20z75_battery_init);
 659
 660 static void __exit bq20z75_battery_exit(void)
 661 {
 662         i2c_del_driver(&bq20z75_battery_driver);
 663 }
 664 module_exit(bq20z75_battery_exit);
 665
 666 MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
 667 MODULE_LICENSE("GPL");