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         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 160         s32 ret = 0;
 161         int retries = 1;
 162
 163         if (bq20z75_device->pdata)
 164                 retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
 165
 166         while (retries > 0) {
 167                 ret = i2c_smbus_read_word_data(client, address);
 168                 if (ret >= 0)
 169                         break;
 170                 retries--;
 171         }
 172
 173         if (ret < 0) {
 174                 dev_warn(&client->dev,
 175                         "%s: i2c read at address 0x%x failed\n",
 176                         __func__, address);
 177                 return ret;
 178         }
 179
 180         return le16_to_cpu(ret);
 181 }
 182
 183 static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
 184         u16 value)
 185 {
 186         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 187         s32 ret = 0;
 188         int retries = 1;
 189
 190         if (bq20z75_device->pdata)
 191                 retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
 192
 193         while (retries > 0) {
 194                 ret = i2c_smbus_write_word_data(client, address,
 195                         le16_to_cpu(value));
 196                 if (ret >= 0)
 197                         break;
 198                 retries--;
 199         }
 200
 201         if (ret < 0) {
 202                 dev_warn(&client->dev,
 203                         "%s: i2c write to address 0x%x failed\n",
 204                         __func__, address);
 205                 return ret;
 206         }
 207
 208         return 0;
 209 }
 210
 211 static int bq20z75_get_battery_presence_and_health(
 212         struct i2c_client *client, enum power_supply_property psp,
 213         union power_supply_propval *val)
 214 {
 215         s32 ret;
 216         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 217
 218         if (psp == POWER_SUPPLY_PROP_PRESENT &&
 219                 bq20z75_device->gpio_detect) {
 220                 ret = gpio_get_value(
 221                         bq20z75_device->pdata->battery_detect);
 222                 if (ret == bq20z75_device->pdata->battery_detect_present)
 223                         val->intval = 1;
 224                 else
 225                         val->intval = 0;
 226                 return ret;
 227         }
 228
 229         /* Write to ManufacturerAccess with
 230          * ManufacturerAccess command and then
 231          * read the status */
 232         ret = bq20z75_write_word_data(client,
 233                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 234                 MANUFACTURER_ACCESS_STATUS);
 235         if (ret < 0)
 236                 return ret;
 237
 238
 239         ret = bq20z75_read_word_data(client,
 240                 bq20z75_data[REG_MANUFACTURER_DATA].addr);
 241         if (ret < 0) {
 242                 if (psp == POWER_SUPPLY_PROP_PRESENT)
 243                         val->intval = 0; /* battery removed */
 244                 return ret;
 245         }
 246
 247         if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
 248             ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
 249                 val->intval = 0;
 250                 return 0;
 251         }
 252
 253         /* Mask the upper nibble of 2nd byte and
 254          * lower byte of response then
 255          * shift the result by 8 to get status*/
 256         ret &= 0x0F00;
 257         ret >>= 8;
 258         if (psp == POWER_SUPPLY_PROP_PRESENT) {
 259                 if (ret == 0x0F)
 260                         /* battery removed */
 261                         val->intval = 0;
 262                 else
 263                         val->intval = 1;
 264         } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
 265                 if (ret == 0x09)
 266                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 267                 else if (ret == 0x0B)
 268                         val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 269                 else if (ret == 0x0C)
 270                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 271                 else
 272                         val->intval = POWER_SUPPLY_HEALTH_GOOD;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int bq20z75_get_battery_property(struct i2c_client *client,
 279         int reg_offset, enum power_supply_property psp,
 280         union power_supply_propval *val)
 281 {
 282         s32 ret;
 283
 284         ret = bq20z75_read_word_data(client,
 285                 bq20z75_data[reg_offset].addr);
 286         if (ret < 0)
 287                 return ret;
 288
 289         /* returned values are 16 bit */
 290         if (bq20z75_data[reg_offset].min_value < 0)
 291                 ret = (s16)ret;
 292
 293         if (ret >= bq20z75_data[reg_offset].min_value &&
 294             ret <= bq20z75_data[reg_offset].max_value) {
 295                 val->intval = ret;
 296                 if (psp == POWER_SUPPLY_PROP_STATUS) {
 297                         if (ret & BATTERY_FULL_CHARGED)
 298                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 299                         else if (ret & BATTERY_FULL_DISCHARGED)
 300                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 301                         else if (ret & BATTERY_DISCHARGING)
 302                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 303                         else
 304                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 305                 }
 306         } else {
 307                 if (psp == POWER_SUPPLY_PROP_STATUS)
 308                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 309                 else
 310                         val->intval = 0;
 311         }
 312
 313         return 0;
 314 }
 315
 316 static void  bq20z75_unit_adjustment(struct i2c_client *client,
 317         enum power_supply_property psp, union power_supply_propval *val)
 318 {
 319 #define BASE_UNIT_CONVERSION            1000
 320 #define BATTERY_MODE_CAP_MULT_WATT      (10 * BASE_UNIT_CONVERSION)
 321 #define TIME_UNIT_CONVERSION            600
 322 #define TEMP_KELVIN_TO_CELCIUS          2731
 323         switch (psp) {
 324         case POWER_SUPPLY_PROP_ENERGY_NOW:
 325         case POWER_SUPPLY_PROP_ENERGY_FULL:
 326         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 327                 val->intval *= BATTERY_MODE_CAP_MULT_WATT;
 328                 break;
 329
 330         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 331         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 332         case POWER_SUPPLY_PROP_CURRENT_NOW:
 333         case POWER_SUPPLY_PROP_CHARGE_NOW:
 334         case POWER_SUPPLY_PROP_CHARGE_FULL:
 335         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 336                 val->intval *= BASE_UNIT_CONVERSION;
 337                 break;
 338
 339         case POWER_SUPPLY_PROP_TEMP:
 340                 /* bq20z75 provides battery tempreture in 0.1°K
 341                  * so convert it to 0.1°C */
 342                 val->intval -= TEMP_KELVIN_TO_CELCIUS;
 343                 val->intval *= 10;
 344                 break;
 345
 346         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 347         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 348                 val->intval *= TIME_UNIT_CONVERSION;
 349                 break;
 350
 351         default:
 352                 dev_dbg(&client->dev,
 353                         "%s: no need for unit conversion %d\n", __func__, psp);
 354         }
 355 }
 356
 357 static enum bq20z75_battery_mode
 358 bq20z75_set_battery_mode(struct i2c_client *client,
 359         enum bq20z75_battery_mode mode)
 360 {
 361         int ret, original_val;
 362
 363         original_val = bq20z75_read_word_data(client, BATTERY_MODE_OFFSET);
 364         if (original_val < 0)
 365                 return original_val;
 366
 367         if ((original_val & BATTERY_MODE_MASK) == mode)
 368                 return mode;
 369
 370         if (mode == BATTERY_MODE_AMPS)
 371                 ret = original_val & ~BATTERY_MODE_MASK;
 372         else
 373                 ret = original_val | BATTERY_MODE_MASK;
 374
 375         ret = bq20z75_write_word_data(client, BATTERY_MODE_OFFSET, ret);
 376         if (ret < 0)
 377                 return ret;
 378
 379         return original_val & BATTERY_MODE_MASK;
 380 }
 381
 382 static int bq20z75_get_battery_capacity(struct i2c_client *client,
 383         int reg_offset, enum power_supply_property psp,
 384         union power_supply_propval *val)
 385 {
 386         s32 ret;
 387         enum bq20z75_battery_mode mode = BATTERY_MODE_WATTS;
 388
 389         if (power_supply_is_amp_property(psp))
 390                 mode = BATTERY_MODE_AMPS;
 391
 392         mode = bq20z75_set_battery_mode(client, mode);
 393         if (mode < 0)
 394                 return mode;
 395
 396         ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
 397         if (ret < 0)
 398                 return ret;
 399
 400         if (psp == POWER_SUPPLY_PROP_CAPACITY) {
 401                 /* bq20z75 spec says that this can be >100 %
 402                 * even if max value is 100 % */
 403                 val->intval = min(ret, 100);
 404         } else
 405                 val->intval = ret;
 406
 407         ret = bq20z75_set_battery_mode(client, mode);
 408         if (ret < 0)
 409                 return ret;
 410
 411         return 0;
 412 }
 413
 414 static char bq20z75_serial[5];
 415 static int bq20z75_get_battery_serial_number(struct i2c_client *client,
 416         union power_supply_propval *val)
 417 {
 418         int ret;
 419
 420         ret = bq20z75_read_word_data(client,
 421                 bq20z75_data[REG_SERIAL_NUMBER].addr);
 422         if (ret < 0)
 423                 return ret;
 424
 425         ret = sprintf(bq20z75_serial, "%04x", ret);
 426         val->strval = bq20z75_serial;
 427
 428         return 0;
 429 }
 430
 431 static int bq20z75_get_property_index(struct i2c_client *client,
 432         enum power_supply_property psp)
 433 {
 434         int count;
 435         for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
 436                 if (psp == bq20z75_data[count].psp)
 437                         return count;
 438
 439         dev_warn(&client->dev,
 440                 "%s: Invalid Property - %d\n", __func__, psp);
 441
 442         return -EINVAL;
 443 }
 444
 445 static int bq20z75_get_property(struct power_supply *psy,
 446         enum power_supply_property psp,
 447         union power_supply_propval *val)
 448 {
 449         int ret = 0;
 450         struct bq20z75_info *bq20z75_device = container_of(psy,
 451                                 struct bq20z75_info, power_supply);
 452         struct i2c_client *client = bq20z75_device->client;
 453
 454         switch (psp) {
 455         case POWER_SUPPLY_PROP_PRESENT:
 456         case POWER_SUPPLY_PROP_HEALTH:
 457                 ret = bq20z75_get_battery_presence_and_health(client, psp, val);
 458                 break;
 459
 460         case POWER_SUPPLY_PROP_TECHNOLOGY:
 461                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 462                 break;
 463
 464         case POWER_SUPPLY_PROP_ENERGY_NOW:
 465         case POWER_SUPPLY_PROP_ENERGY_FULL:
 466         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 467         case POWER_SUPPLY_PROP_CHARGE_NOW:
 468         case POWER_SUPPLY_PROP_CHARGE_FULL:
 469         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 470         case POWER_SUPPLY_PROP_CAPACITY:
 471                 ret = bq20z75_get_property_index(client, psp);
 472                 if (ret < 0)
 473                         break;
 474
 475                 ret = bq20z75_get_battery_capacity(client, ret, psp, val);
 476                 break;
 477
 478         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 479                 ret = bq20z75_get_battery_serial_number(client, val);
 480                 break;
 481
 482         case POWER_SUPPLY_PROP_STATUS:
 483         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 484         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 485         case POWER_SUPPLY_PROP_CURRENT_NOW:
 486         case POWER_SUPPLY_PROP_TEMP:
 487         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 488         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 489         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 490                 ret = bq20z75_get_property_index(client, psp);
 491                 if (ret < 0)
 492                         break;
 493
 494                 ret = bq20z75_get_battery_property(client, ret, psp, val);
 495                 break;
 496
 497         default:
 498                 dev_err(&client->dev,
 499                         "%s: INVALID property\n", __func__);
 500                 return -EINVAL;
 501         }
 502
 503         if (!bq20z75_device->enable_detection)
 504                 goto done;
 505
 506         if (!bq20z75_device->gpio_detect &&
 507                 bq20z75_device->is_present != (ret >= 0)) {
 508                 bq20z75_device->is_present = (ret >= 0);
 509                 power_supply_changed(&bq20z75_device->power_supply);
 510         }
 511
 512 done:
 513         if (!ret) {
 514                 /* Convert units to match requirements for power supply class */
 515                 bq20z75_unit_adjustment(client, psp, val);
 516         }
 517
 518         dev_dbg(&client->dev,
 519                 "%s: property = %d, value = %d\n", __func__, psp, val->intval);
 520
 521         return ret;
 522 }
 523
 524 static irqreturn_t bq20z75_irq(int irq, void *devid)
 525 {
 526         struct power_supply *battery = devid;
 527
 528         power_supply_changed(battery);
 529
 530         return IRQ_HANDLED;
 531 }
 532
 533 static int __devinit bq20z75_probe(struct i2c_client *client,
 534         const struct i2c_device_id *id)
 535 {
 536         struct bq20z75_info *bq20z75_device;
 537         struct bq20z75_platform_data *pdata = client->dev.platform_data;
 538         int rc;
 539         int irq;
 540
 541         bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
 542         if (!bq20z75_device)
 543                 return -ENOMEM;
 544
 545         bq20z75_device->client = client;
 546         bq20z75_device->enable_detection = false;
 547         bq20z75_device->gpio_detect = false;
 548         bq20z75_device->power_supply.name = "battery";
 549         bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
 550         bq20z75_device->power_supply.properties = bq20z75_properties;
 551         bq20z75_device->power_supply.num_properties =
 552                 ARRAY_SIZE(bq20z75_properties);
 553         bq20z75_device->power_supply.get_property = bq20z75_get_property;
 554
 555         if (pdata) {
 556                 bq20z75_device->gpio_detect =
 557                         gpio_is_valid(pdata->battery_detect);
 558                 bq20z75_device->pdata = pdata;
 559         }
 560
 561         i2c_set_clientdata(client, bq20z75_device);
 562
 563         if (!bq20z75_device->gpio_detect)
 564                 goto skip_gpio;
 565
 566         rc = gpio_request(pdata->battery_detect, dev_name(&client->dev));
 567         if (rc) {
 568                 dev_warn(&client->dev, "Failed to request gpio: %d\n", rc);
 569                 bq20z75_device->gpio_detect = false;
 570                 goto skip_gpio;
 571         }
 572
 573         rc = gpio_direction_input(pdata->battery_detect);
 574         if (rc) {
 575                 dev_warn(&client->dev, "Failed to get gpio as input: %d\n", rc);
 576                 gpio_free(pdata->battery_detect);
 577                 bq20z75_device->gpio_detect = false;
 578                 goto skip_gpio;
 579         }
 580
 581         irq = gpio_to_irq(pdata->battery_detect);
 582         if (irq <= 0) {
 583                 dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
 584                 gpio_free(pdata->battery_detect);
 585                 bq20z75_device->gpio_detect = false;
 586                 goto skip_gpio;
 587         }
 588
 589         rc = request_irq(irq, bq20z75_irq,
 590                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 591                 dev_name(&client->dev), &bq20z75_device->power_supply);
 592         if (rc) {
 593                 dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
 594                 gpio_free(pdata->battery_detect);
 595                 bq20z75_device->gpio_detect = false;
 596                 goto skip_gpio;
 597         }
 598
 599         bq20z75_device->irq = irq;
 600
 601 skip_gpio:
 602
 603         rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
 604         if (rc) {
 605                 dev_err(&client->dev,
 606                         "%s: Failed to register power supply\n", __func__);
 607                 goto exit_psupply;
 608         }
 609
 610         dev_info(&client->dev,
 611                 "%s: battery gas gauge device registered\n", client->name);
 612
 613         return 0;
 614
 615 exit_psupply:
 616         if (bq20z75_device->irq)
 617                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 618         if (bq20z75_device->gpio_detect)
 619                 gpio_free(pdata->battery_detect);
 620
 621         kfree(bq20z75_device);
 622
 623         return rc;
 624 }
 625
 626 static int __devexit bq20z75_remove(struct i2c_client *client)
 627 {
 628         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 629
 630         if (bq20z75_device->irq)
 631                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 632         if (bq20z75_device->gpio_detect)
 633                 gpio_free(bq20z75_device->pdata->battery_detect);
 634
 635         power_supply_unregister(&bq20z75_device->power_supply);
 636         kfree(bq20z75_device);
 637         bq20z75_device = NULL;
 638
 639         return 0;
 640 }
 641
 642 #if defined CONFIG_PM
 643 static int bq20z75_suspend(struct i2c_client *client,
 644         pm_message_t state)
 645 {
 646         s32 ret;
 647
 648         /* write to manufacturer access with sleep command */
 649         ret = bq20z75_write_word_data(client,
 650                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 651                 MANUFACTURER_ACCESS_SLEEP);
 652         if (ret < 0)
 653                 return ret;
 654
 655         return 0;
 656 }
 657 #else
 658 #define bq20z75_suspend         NULL
 659 #endif
 660 /* any smbus transaction will wake up bq20z75 */
 661 #define bq20z75_resume          NULL
 662
 663 static const struct i2c_device_id bq20z75_id[] = {
 664         { "bq20z75", 0 },
 665         {}
 666 };
 667 MODULE_DEVICE_TABLE(i2c, bq20z75_id);
 668
 669 static struct i2c_driver bq20z75_battery_driver = {
 670         .probe          = bq20z75_probe,
 671         .remove         = __devexit_p(bq20z75_remove),
 672         .suspend        = bq20z75_suspend,
 673         .resume         = bq20z75_resume,
 674         .id_table       = bq20z75_id,
 675         .driver = {
 676                 .name   = "bq20z75-battery",
 677         },
 678 };
 679
 680 static int __init bq20z75_battery_init(void)
 681 {
 682         return i2c_add_driver(&bq20z75_battery_driver);
 683 }
 684 module_init(bq20z75_battery_init);
 685
 686 static void __exit bq20z75_battery_exit(void)
 687 {
 688         i2c_del_driver(&bq20z75_battery_driver);
 689 }
 690 module_exit(bq20z75_battery_exit);
 691
 692 MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
 693 MODULE_LICENSE("GPL");