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         int                             last_state;
 156         int                             poll_time;
 157         struct delayed_work             work;
 158         int                             ignore_changes;
 159 };
 160
 161 static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
 162 {
 163         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 164         s32 ret = 0;
 165         int retries = 1;
 166
 167         if (bq20z75_device->pdata)
 168                 retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
 169
 170         while (retries > 0) {
 171                 ret = i2c_smbus_read_word_data(client, address);
 172                 if (ret >= 0)
 173                         break;
 174                 retries--;
 175         }
 176
 177         if (ret < 0) {
 178                 dev_dbg(&client->dev,
 179                         "%s: i2c read at address 0x%x failed\n",
 180                         __func__, address);
 181                 return ret;
 182         }
 183
 184         return le16_to_cpu(ret);
 185 }
 186
 187 static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
 188         u16 value)
 189 {
 190         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 191         s32 ret = 0;
 192         int retries = 1;
 193
 194         if (bq20z75_device->pdata)
 195                 retries = max(bq20z75_device->pdata->i2c_retry_count + 1, 1);
 196
 197         while (retries > 0) {
 198                 ret = i2c_smbus_write_word_data(client, address,
 199                         le16_to_cpu(value));
 200                 if (ret >= 0)
 201                         break;
 202                 retries--;
 203         }
 204
 205         if (ret < 0) {
 206                 dev_dbg(&client->dev,
 207                         "%s: i2c write to address 0x%x failed\n",
 208                         __func__, address);
 209                 return ret;
 210         }
 211
 212         return 0;
 213 }
 214
 215 static int bq20z75_get_battery_presence_and_health(
 216         struct i2c_client *client, enum power_supply_property psp,
 217         union power_supply_propval *val)
 218 {
 219         s32 ret;
 220         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 221
 222         if (psp == POWER_SUPPLY_PROP_PRESENT &&
 223                 bq20z75_device->gpio_detect) {
 224                 ret = gpio_get_value(
 225                         bq20z75_device->pdata->battery_detect);
 226                 if (ret == bq20z75_device->pdata->battery_detect_present)
 227                         val->intval = 1;
 228                 else
 229                         val->intval = 0;
 230                 bq20z75_device->is_present = val->intval;
 231                 return ret;
 232         }
 233
 234         /* Write to ManufacturerAccess with
 235          * ManufacturerAccess command and then
 236          * read the status */
 237         ret = bq20z75_write_word_data(client,
 238                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 239                 MANUFACTURER_ACCESS_STATUS);
 240         if (ret < 0) {
 241                 if (psp == POWER_SUPPLY_PROP_PRESENT)
 242                         val->intval = 0; /* battery removed */
 243                 return ret;
 244         }
 245
 246         ret = bq20z75_read_word_data(client,
 247                 bq20z75_data[REG_MANUFACTURER_DATA].addr);
 248         if (ret < 0)
 249                 return ret;
 250
 251         if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
 252             ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
 253                 val->intval = 0;
 254                 return 0;
 255         }
 256
 257         /* Mask the upper nibble of 2nd byte and
 258          * lower byte of response then
 259          * shift the result by 8 to get status*/
 260         ret &= 0x0F00;
 261         ret >>= 8;
 262         if (psp == POWER_SUPPLY_PROP_PRESENT) {
 263                 if (ret == 0x0F)
 264                         /* battery removed */
 265                         val->intval = 0;
 266                 else
 267                         val->intval = 1;
 268         } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
 269                 if (ret == 0x09)
 270                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 271                 else if (ret == 0x0B)
 272                         val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 273                 else if (ret == 0x0C)
 274                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 275                 else
 276                         val->intval = POWER_SUPPLY_HEALTH_GOOD;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int bq20z75_get_battery_property(struct i2c_client *client,
 283         int reg_offset, enum power_supply_property psp,
 284         union power_supply_propval *val)
 285 {
 286         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 287         s32 ret;
 288
 289         ret = bq20z75_read_word_data(client,
 290                 bq20z75_data[reg_offset].addr);
 291         if (ret < 0)
 292                 return ret;
 293
 294         /* returned values are 16 bit */
 295         if (bq20z75_data[reg_offset].min_value < 0)
 296                 ret = (s16)ret;
 297
 298         if (ret >= bq20z75_data[reg_offset].min_value &&
 299             ret <= bq20z75_data[reg_offset].max_value) {
 300                 val->intval = ret;
 301                 if (psp != POWER_SUPPLY_PROP_STATUS)
 302                         return 0;
 303
 304                 if (ret & BATTERY_FULL_CHARGED)
 305                         val->intval = POWER_SUPPLY_STATUS_FULL;
 306                 else if (ret & BATTERY_FULL_DISCHARGED)
 307                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 308                 else if (ret & BATTERY_DISCHARGING)
 309                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 310                 else
 311                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 312
 313                 if (bq20z75_device->poll_time == 0)
 314                         bq20z75_device->last_state = val->intval;
 315                 else if (bq20z75_device->last_state != val->intval) {
 316                         cancel_delayed_work_sync(&bq20z75_device->work);
 317                         power_supply_changed(&bq20z75_device->power_supply);
 318                         bq20z75_device->poll_time = 0;
 319                 }
 320         } else {
 321                 if (psp == POWER_SUPPLY_PROP_STATUS)
 322                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 323                 else
 324                         val->intval = 0;
 325         }
 326
 327         return 0;
 328 }
 329
 330 static void  bq20z75_unit_adjustment(struct i2c_client *client,
 331         enum power_supply_property psp, union power_supply_propval *val)
 332 {
 333 #define BASE_UNIT_CONVERSION            1000
 334 #define BATTERY_MODE_CAP_MULT_WATT      (10 * BASE_UNIT_CONVERSION)
 335 #define TIME_UNIT_CONVERSION            60
 336 #define TEMP_KELVIN_TO_CELSIUS          2731
 337         switch (psp) {
 338         case POWER_SUPPLY_PROP_ENERGY_NOW:
 339         case POWER_SUPPLY_PROP_ENERGY_FULL:
 340         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 341                 /* bq20z75 provides energy in units of 10mWh.
 342                  * Convert to µWh
 343                  */
 344                 val->intval *= BATTERY_MODE_CAP_MULT_WATT;
 345                 break;
 346
 347         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 348         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 349         case POWER_SUPPLY_PROP_CURRENT_NOW:
 350         case POWER_SUPPLY_PROP_CHARGE_NOW:
 351         case POWER_SUPPLY_PROP_CHARGE_FULL:
 352         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 353                 val->intval *= BASE_UNIT_CONVERSION;
 354                 break;
 355
 356         case POWER_SUPPLY_PROP_TEMP:
 357                 /* bq20z75 provides battery temperature in 0.1K
 358                  * so convert it to 0.1°C
 359                  */
 360                 val->intval -= TEMP_KELVIN_TO_CELSIUS;
 361                 break;
 362
 363         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 364         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 365                 /* bq20z75 provides time to empty and time to full in minutes.
 366                  * Convert to seconds
 367                  */
 368                 val->intval *= TIME_UNIT_CONVERSION;
 369                 break;
 370
 371         default:
 372                 dev_dbg(&client->dev,
 373                         "%s: no need for unit conversion %d\n", __func__, psp);
 374         }
 375 }
 376
 377 static enum bq20z75_battery_mode
 378 bq20z75_set_battery_mode(struct i2c_client *client,
 379         enum bq20z75_battery_mode mode)
 380 {
 381         int ret, original_val;
 382
 383         original_val = bq20z75_read_word_data(client, BATTERY_MODE_OFFSET);
 384         if (original_val < 0)
 385                 return original_val;
 386
 387         if ((original_val & BATTERY_MODE_MASK) == mode)
 388                 return mode;
 389
 390         if (mode == BATTERY_MODE_AMPS)
 391                 ret = original_val & ~BATTERY_MODE_MASK;
 392         else
 393                 ret = original_val | BATTERY_MODE_MASK;
 394
 395         ret = bq20z75_write_word_data(client, BATTERY_MODE_OFFSET, ret);
 396         if (ret < 0)
 397                 return ret;
 398
 399         return original_val & BATTERY_MODE_MASK;
 400 }
 401
 402 static int bq20z75_get_battery_capacity(struct i2c_client *client,
 403         int reg_offset, enum power_supply_property psp,
 404         union power_supply_propval *val)
 405 {
 406         s32 ret;
 407         enum bq20z75_battery_mode mode = BATTERY_MODE_WATTS;
 408
 409         if (power_supply_is_amp_property(psp))
 410                 mode = BATTERY_MODE_AMPS;
 411
 412         mode = bq20z75_set_battery_mode(client, mode);
 413         if (mode < 0)
 414                 return mode;
 415
 416         ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
 417         if (ret < 0)
 418                 return ret;
 419
 420         if (psp == POWER_SUPPLY_PROP_CAPACITY) {
 421                 /* bq20z75 spec says that this can be >100 %
 422                 * even if max value is 100 % */
 423                 val->intval = min(ret, 100);
 424         } else
 425                 val->intval = ret;
 426
 427         ret = bq20z75_set_battery_mode(client, mode);
 428         if (ret < 0)
 429                 return ret;
 430
 431         return 0;
 432 }
 433
 434 static char bq20z75_serial[5];
 435 static int bq20z75_get_battery_serial_number(struct i2c_client *client,
 436         union power_supply_propval *val)
 437 {
 438         int ret;
 439
 440         ret = bq20z75_read_word_data(client,
 441                 bq20z75_data[REG_SERIAL_NUMBER].addr);
 442         if (ret < 0)
 443                 return ret;
 444
 445         ret = sprintf(bq20z75_serial, "%04x", ret);
 446         val->strval = bq20z75_serial;
 447
 448         return 0;
 449 }
 450
 451 static int bq20z75_get_property_index(struct i2c_client *client,
 452         enum power_supply_property psp)
 453 {
 454         int count;
 455         for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++)
 456                 if (psp == bq20z75_data[count].psp)
 457                         return count;
 458
 459         dev_warn(&client->dev,
 460                 "%s: Invalid Property - %d\n", __func__, psp);
 461
 462         return -EINVAL;
 463 }
 464
 465 static int bq20z75_get_property(struct power_supply *psy,
 466         enum power_supply_property psp,
 467         union power_supply_propval *val)
 468 {
 469         int ret = 0;
 470         struct bq20z75_info *bq20z75_device = container_of(psy,
 471                                 struct bq20z75_info, power_supply);
 472         struct i2c_client *client = bq20z75_device->client;
 473
 474         switch (psp) {
 475         case POWER_SUPPLY_PROP_PRESENT:
 476         case POWER_SUPPLY_PROP_HEALTH:
 477                 ret = bq20z75_get_battery_presence_and_health(client, psp, val);
 478                 if (psp == POWER_SUPPLY_PROP_PRESENT)
 479                         return 0;
 480                 break;
 481
 482         case POWER_SUPPLY_PROP_TECHNOLOGY:
 483                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 484                 break;
 485
 486         case POWER_SUPPLY_PROP_ENERGY_NOW:
 487         case POWER_SUPPLY_PROP_ENERGY_FULL:
 488         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 489         case POWER_SUPPLY_PROP_CHARGE_NOW:
 490         case POWER_SUPPLY_PROP_CHARGE_FULL:
 491         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 492         case POWER_SUPPLY_PROP_CAPACITY:
 493                 ret = bq20z75_get_property_index(client, psp);
 494                 if (ret < 0)
 495                         break;
 496
 497                 ret = bq20z75_get_battery_capacity(client, ret, psp, val);
 498                 break;
 499
 500         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 501                 ret = bq20z75_get_battery_serial_number(client, val);
 502                 break;
 503
 504         case POWER_SUPPLY_PROP_STATUS:
 505         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 506         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 507         case POWER_SUPPLY_PROP_CURRENT_NOW:
 508         case POWER_SUPPLY_PROP_TEMP:
 509         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 510         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 511         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 512                 ret = bq20z75_get_property_index(client, psp);
 513                 if (ret < 0)
 514                         break;
 515
 516                 ret = bq20z75_get_battery_property(client, ret, psp, val);
 517                 break;
 518
 519         default:
 520                 dev_err(&client->dev,
 521                         "%s: INVALID property\n", __func__);
 522                 return -EINVAL;
 523         }
 524
 525         if (!bq20z75_device->enable_detection)
 526                 goto done;
 527
 528         if (!bq20z75_device->gpio_detect &&
 529                 bq20z75_device->is_present != (ret >= 0)) {
 530                 bq20z75_device->is_present = (ret >= 0);
 531                 power_supply_changed(&bq20z75_device->power_supply);
 532         }
 533
 534 done:
 535         if (!ret) {
 536                 /* Convert units to match requirements for power supply class */
 537                 bq20z75_unit_adjustment(client, psp, val);
 538         }
 539
 540         dev_dbg(&client->dev,
 541                 "%s: property = %d, value = %x\n", __func__, psp, val->intval);
 542
 543         if (ret && bq20z75_device->is_present)
 544                 return ret;
 545
 546         /* battery not present, so return NODATA for properties */
 547         if (ret)
 548                 return -ENODATA;
 549
 550         return 0;
 551 }
 552
 553 static irqreturn_t bq20z75_irq(int irq, void *devid)
 554 {
 555         struct power_supply *battery = devid;
 556
 557         power_supply_changed(battery);
 558
 559         return IRQ_HANDLED;
 560 }
 561
 562 static void bq20z75_external_power_changed(struct power_supply *psy)
 563 {
 564         struct bq20z75_info *bq20z75_device;
 565
 566         bq20z75_device = container_of(psy, struct bq20z75_info, power_supply);
 567
 568         if (bq20z75_device->ignore_changes > 0) {
 569                 bq20z75_device->ignore_changes--;
 570                 return;
 571         }
 572
 573         /* cancel outstanding work */
 574         cancel_delayed_work_sync(&bq20z75_device->work);
 575
 576         schedule_delayed_work(&bq20z75_device->work, HZ);
 577         bq20z75_device->poll_time = bq20z75_device->pdata->poll_retry_count;
 578 }
 579
 580 static void bq20z75_delayed_work(struct work_struct *work)
 581 {
 582         struct bq20z75_info *bq20z75_device;
 583         s32 ret;
 584
 585         bq20z75_device = container_of(work, struct bq20z75_info, work.work);
 586
 587         ret = bq20z75_read_word_data(bq20z75_device->client,
 588                                      bq20z75_data[REG_STATUS].addr);
 589         /* if the read failed, give up on this work */
 590         if (ret < 0) {
 591                 bq20z75_device->poll_time = 0;
 592                 return;
 593         }
 594
 595         if (ret & BATTERY_FULL_CHARGED)
 596                 ret = POWER_SUPPLY_STATUS_FULL;
 597         else if (ret & BATTERY_FULL_DISCHARGED)
 598                 ret = POWER_SUPPLY_STATUS_NOT_CHARGING;
 599         else if (ret & BATTERY_DISCHARGING)
 600                 ret = POWER_SUPPLY_STATUS_DISCHARGING;
 601         else
 602                 ret = POWER_SUPPLY_STATUS_CHARGING;
 603
 604         if (bq20z75_device->last_state != ret) {
 605                 bq20z75_device->poll_time = 0;
 606                 power_supply_changed(&bq20z75_device->power_supply);
 607                 return;
 608         }
 609         if (bq20z75_device->poll_time > 0) {
 610                 schedule_delayed_work(&bq20z75_device->work, HZ);
 611                 bq20z75_device->poll_time--;
 612                 return;
 613         }
 614 }
 615
 616 static int __devinit bq20z75_probe(struct i2c_client *client,
 617         const struct i2c_device_id *id)
 618 {
 619         struct bq20z75_info *bq20z75_device;
 620         struct bq20z75_platform_data *pdata = client->dev.platform_data;
 621         int rc;
 622         int irq;
 623
 624         bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
 625         if (!bq20z75_device)
 626                 return -ENOMEM;
 627
 628         bq20z75_device->client = client;
 629         bq20z75_device->enable_detection = false;
 630         bq20z75_device->gpio_detect = false;
 631         bq20z75_device->power_supply.name = "battery";
 632         bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
 633         bq20z75_device->power_supply.properties = bq20z75_properties;
 634         bq20z75_device->power_supply.num_properties =
 635                 ARRAY_SIZE(bq20z75_properties);
 636         bq20z75_device->power_supply.get_property = bq20z75_get_property;
 637         /* ignore first notification of external change, it is generated
 638          * from the power_supply_register call back
 639          */
 640         bq20z75_device->ignore_changes = 1;
 641         bq20z75_device->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
 642         bq20z75_device->power_supply.external_power_changed =
 643                 bq20z75_external_power_changed;
 644
 645         if (pdata) {
 646                 bq20z75_device->gpio_detect =
 647                         gpio_is_valid(pdata->battery_detect);
 648                 bq20z75_device->pdata = pdata;
 649         }
 650
 651         i2c_set_clientdata(client, bq20z75_device);
 652
 653         if (!bq20z75_device->gpio_detect)
 654                 goto skip_gpio;
 655
 656         rc = gpio_request(pdata->battery_detect, dev_name(&client->dev));
 657         if (rc) {
 658                 dev_warn(&client->dev, "Failed to request gpio: %d\n", rc);
 659                 bq20z75_device->gpio_detect = false;
 660                 goto skip_gpio;
 661         }
 662
 663         rc = gpio_direction_input(pdata->battery_detect);
 664         if (rc) {
 665                 dev_warn(&client->dev, "Failed to get gpio as input: %d\n", rc);
 666                 gpio_free(pdata->battery_detect);
 667                 bq20z75_device->gpio_detect = false;
 668                 goto skip_gpio;
 669         }
 670
 671         irq = gpio_to_irq(pdata->battery_detect);
 672         if (irq <= 0) {
 673                 dev_warn(&client->dev, "Failed to get gpio as irq: %d\n", irq);
 674                 gpio_free(pdata->battery_detect);
 675                 bq20z75_device->gpio_detect = false;
 676                 goto skip_gpio;
 677         }
 678
 679         rc = request_irq(irq, bq20z75_irq,
 680                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 681                 dev_name(&client->dev), &bq20z75_device->power_supply);
 682         if (rc) {
 683                 dev_warn(&client->dev, "Failed to request irq: %d\n", rc);
 684                 gpio_free(pdata->battery_detect);
 685                 bq20z75_device->gpio_detect = false;
 686                 goto skip_gpio;
 687         }
 688
 689         bq20z75_device->irq = irq;
 690
 691 skip_gpio:
 692
 693         rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
 694         if (rc) {
 695                 dev_err(&client->dev,
 696                         "%s: Failed to register power supply\n", __func__);
 697                 goto exit_psupply;
 698         }
 699
 700         dev_info(&client->dev,
 701                 "%s: battery gas gauge device registered\n", client->name);
 702
 703         INIT_DELAYED_WORK(&bq20z75_device->work, bq20z75_delayed_work);
 704
 705         bq20z75_device->enable_detection = true;
 706
 707         return 0;
 708
 709 exit_psupply:
 710         if (bq20z75_device->irq)
 711                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 712         if (bq20z75_device->gpio_detect)
 713                 gpio_free(pdata->battery_detect);
 714
 715         kfree(bq20z75_device);
 716
 717         return rc;
 718 }
 719
 720 static int __devexit bq20z75_remove(struct i2c_client *client)
 721 {
 722         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 723
 724         if (bq20z75_device->irq)
 725                 free_irq(bq20z75_device->irq, &bq20z75_device->power_supply);
 726         if (bq20z75_device->gpio_detect)
 727                 gpio_free(bq20z75_device->pdata->battery_detect);
 728
 729         power_supply_unregister(&bq20z75_device->power_supply);
 730
 731         cancel_delayed_work_sync(&bq20z75_device->work);
 732
 733         kfree(bq20z75_device);
 734         bq20z75_device = NULL;
 735
 736         return 0;
 737 }
 738
 739 #if defined CONFIG_PM
 740 static int bq20z75_suspend(struct i2c_client *client,
 741         pm_message_t state)
 742 {
 743         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 744         s32 ret;
 745
 746         if (bq20z75_device->poll_time > 0)
 747                 cancel_delayed_work_sync(&bq20z75_device->work);
 748
 749         /* write to manufacturer access with sleep command */
 750         ret = bq20z75_write_word_data(client,
 751                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 752                 MANUFACTURER_ACCESS_SLEEP);
 753         if (bq20z75_device->is_present && ret < 0)
 754                 return ret;
 755
 756         return 0;
 757 }
 758 #else
 759 #define bq20z75_suspend         NULL
 760 #endif
 761 /* any smbus transaction will wake up bq20z75 */
 762 #define bq20z75_resume          NULL
 763
 764 static const struct i2c_device_id bq20z75_id[] = {
 765         { "bq20z75", 0 },
 766         {}
 767 };
 768 MODULE_DEVICE_TABLE(i2c, bq20z75_id);
 769
 770 static struct i2c_driver bq20z75_battery_driver = {
 771         .probe          = bq20z75_probe,
 772         .remove         = __devexit_p(bq20z75_remove),
 773         .suspend        = bq20z75_suspend,
 774         .resume         = bq20z75_resume,
 775         .id_table       = bq20z75_id,
 776         .driver = {
 777                 .name   = "bq20z75-battery",
 778         },
 779 };
 780
 781 static int __init bq20z75_battery_init(void)
 782 {
 783         return i2c_add_driver(&bq20z75_battery_driver);
 784 }
 785 module_init(bq20z75_battery_init);
 786
 787 static void __exit bq20z75_battery_exit(void)
 788 {
 789         i2c_del_driver(&bq20z75_battery_driver);
 790 }
 791 module_exit(bq20z75_battery_exit);
 792
 793 MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
 794 MODULE_LICENSE("GPL");