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
  29 enum {
  30         REG_MANUFACTURER_DATA,
  31         REG_TEMPERATURE,
  32         REG_VOLTAGE,
  33         REG_CURRENT,
  34         REG_CAPACITY,
  35         REG_TIME_TO_EMPTY,
  36         REG_TIME_TO_FULL,
  37         REG_STATUS,
  38         REG_CYCLE_COUNT,
  39         REG_SERIAL_NUMBER,
  40         REG_REMAINING_CAPACITY,
  41         REG_FULL_CHARGE_CAPACITY,
  42         REG_DESIGN_CAPACITY,
  43         REG_DESIGN_VOLTAGE,
  44 };
  45
  46 /* manufacturer access defines */
  47 #define MANUFACTURER_ACCESS_STATUS      0x0006
  48 #define MANUFACTURER_ACCESS_SLEEP       0x0011
  49
  50 /* battery status value bits */
  51 #define BATTERY_DISCHARGING             0x40
  52 #define BATTERY_FULL_CHARGED            0x20
  53 #define BATTERY_FULL_DISCHARGED         0x10
  54
  55 #define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
  56         .psp = _psp, \
  57         .addr = _addr, \
  58         .min_value = _min_value, \
  59         .max_value = _max_value, \
  60 }
  61
  62 static const struct bq20z75_device_data {
  63         enum power_supply_property psp;
  64         u8 addr;
  65         int min_value;
  66         int max_value;
  67 } bq20z75_data[] = {
  68         [REG_MANUFACTURER_DATA] =
  69                 BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
  70         [REG_TEMPERATURE] =
  71                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
  72         [REG_VOLTAGE] =
  73                 BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
  74         [REG_CURRENT] =
  75                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
  76                         32767),
  77         [REG_CAPACITY] =
  78                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
  79         [REG_REMAINING_CAPACITY] =
  80                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
  81         [REG_FULL_CHARGE_CAPACITY] =
  82                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
  83         [REG_TIME_TO_EMPTY] =
  84                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
  85                         65535),
  86         [REG_TIME_TO_FULL] =
  87                 BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
  88                         65535),
  89         [REG_STATUS] =
  90                 BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
  91         [REG_CYCLE_COUNT] =
  92                 BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
  93         [REG_DESIGN_CAPACITY] =
  94                 BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
  95                         65535),
  96         [REG_DESIGN_VOLTAGE] =
  97                 BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
  98                         65535),
  99         [REG_SERIAL_NUMBER] =
 100                 BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
 101 };
 102
 103 static enum power_supply_property bq20z75_properties[] = {
 104         POWER_SUPPLY_PROP_STATUS,
 105         POWER_SUPPLY_PROP_HEALTH,
 106         POWER_SUPPLY_PROP_PRESENT,
 107         POWER_SUPPLY_PROP_TECHNOLOGY,
 108         POWER_SUPPLY_PROP_CYCLE_COUNT,
 109         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 110         POWER_SUPPLY_PROP_CURRENT_NOW,
 111         POWER_SUPPLY_PROP_CAPACITY,
 112         POWER_SUPPLY_PROP_TEMP,
 113         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 114         POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
 115         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 116         POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 117         POWER_SUPPLY_PROP_ENERGY_NOW,
 118         POWER_SUPPLY_PROP_ENERGY_FULL,
 119         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 120 };
 121
 122 struct bq20z75_info {
 123         struct i2c_client       *client;
 124         struct power_supply     power_supply;
 125 };
 126
 127 static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
 128 {
 129         s32 ret;
 130
 131         ret = i2c_smbus_read_word_data(client, address);
 132         if (ret < 0) {
 133                 dev_err(&client->dev,
 134                         "%s: i2c read at address 0x%x failed\n",
 135                         __func__, address);
 136                 return ret;
 137         }
 138         return le16_to_cpu(ret);
 139 }
 140
 141 static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
 142         u16 value)
 143 {
 144         s32 ret;
 145
 146         ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
 147         if (ret < 0) {
 148                 dev_err(&client->dev,
 149                         "%s: i2c write to address 0x%x failed\n",
 150                         __func__, address);
 151                 return ret;
 152         }
 153         return 0;
 154 }
 155
 156 static int bq20z75_get_battery_presence_and_health(
 157         struct i2c_client *client, enum power_supply_property psp,
 158         union power_supply_propval *val)
 159 {
 160         s32 ret;
 161
 162         /* Write to ManufacturerAccess with
 163          * ManufacturerAccess command and then
 164          * read the status */
 165         ret = bq20z75_write_word_data(client,
 166                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 167                 MANUFACTURER_ACCESS_STATUS);
 168         if (ret < 0)
 169                 return ret;
 170
 171
 172         ret = bq20z75_read_word_data(client,
 173                 bq20z75_data[REG_MANUFACTURER_DATA].addr);
 174         if (ret < 0)
 175                 return ret;
 176
 177         if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
 178             ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
 179                 val->intval = 0;
 180                 return 0;
 181         }
 182
 183         /* Mask the upper nibble of 2nd byte and
 184          * lower byte of response then
 185          * shift the result by 8 to get status*/
 186         ret &= 0x0F00;
 187         ret >>= 8;
 188         if (psp == POWER_SUPPLY_PROP_PRESENT) {
 189                 if (ret == 0x0F)
 190                         /* battery removed */
 191                         val->intval = 0;
 192                 else
 193                         val->intval = 1;
 194         } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
 195                 if (ret == 0x09)
 196                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 197                 else if (ret == 0x0B)
 198                         val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 199                 else if (ret == 0x0C)
 200                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 201                 else
 202                         val->intval = POWER_SUPPLY_HEALTH_GOOD;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static int bq20z75_get_battery_property(struct i2c_client *client,
 209         int reg_offset, enum power_supply_property psp,
 210         union power_supply_propval *val)
 211 {
 212         s32 ret;
 213
 214         ret = bq20z75_read_word_data(client,
 215                 bq20z75_data[reg_offset].addr);
 216         if (ret < 0)
 217                 return ret;
 218
 219         /* returned values are 16 bit */
 220         if (bq20z75_data[reg_offset].min_value < 0)
 221                 ret = (s16)ret;
 222
 223         if (ret >= bq20z75_data[reg_offset].min_value &&
 224             ret <= bq20z75_data[reg_offset].max_value) {
 225                 val->intval = ret;
 226                 if (psp == POWER_SUPPLY_PROP_STATUS) {
 227                         if (ret & BATTERY_FULL_CHARGED)
 228                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 229                         else if (ret & BATTERY_FULL_DISCHARGED)
 230                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 231                         else if (ret & BATTERY_DISCHARGING)
 232                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 233                         else
 234                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 235                 }
 236         } else {
 237                 if (psp == POWER_SUPPLY_PROP_STATUS)
 238                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 239                 else
 240                         val->intval = 0;
 241         }
 242
 243         return 0;
 244 }
 245
 246 static void  bq20z75_unit_adjustment(struct i2c_client *client,
 247         enum power_supply_property psp, union power_supply_propval *val)
 248 {
 249 #define BASE_UNIT_CONVERSION            1000
 250 #define BATTERY_MODE_CAP_MULT_WATT      (10 * BASE_UNIT_CONVERSION)
 251 #define TIME_UNIT_CONVERSION            600
 252 #define TEMP_KELVIN_TO_CELCIUS          2731
 253         switch (psp) {
 254         case POWER_SUPPLY_PROP_ENERGY_NOW:
 255         case POWER_SUPPLY_PROP_ENERGY_FULL:
 256         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 257                 val->intval *= BATTERY_MODE_CAP_MULT_WATT;
 258                 break;
 259
 260         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 261         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 262         case POWER_SUPPLY_PROP_CURRENT_NOW:
 263                 val->intval *= BASE_UNIT_CONVERSION;
 264                 break;
 265
 266         case POWER_SUPPLY_PROP_TEMP:
 267                 /* bq20z75 provides battery tempreture in 0.1°K
 268                  * so convert it to 0.1°C */
 269                 val->intval -= TEMP_KELVIN_TO_CELCIUS;
 270                 val->intval *= 10;
 271                 break;
 272
 273         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 274         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 275                 val->intval *= TIME_UNIT_CONVERSION;
 276                 break;
 277
 278         default:
 279                 dev_dbg(&client->dev,
 280                         "%s: no need for unit conversion %d\n", __func__, psp);
 281         }
 282 }
 283
 284 static int bq20z75_get_battery_capacity(struct i2c_client *client,
 285         int reg_offset, enum power_supply_property psp,
 286         union power_supply_propval *val)
 287 {
 288         s32 ret;
 289
 290         ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
 291         if (ret < 0)
 292                 return ret;
 293
 294         if (psp == POWER_SUPPLY_PROP_CAPACITY) {
 295                 /* bq20z75 spec says that this can be >100 %
 296                 * even if max value is 100 % */
 297                 val->intval = min(ret, 100);
 298         } else
 299                 val->intval = ret;
 300
 301         return 0;
 302 }
 303
 304 static char bq20z75_serial[5];
 305 static int bq20z75_get_battery_serial_number(struct i2c_client *client,
 306         union power_supply_propval *val)
 307 {
 308         int ret;
 309
 310         ret = bq20z75_read_word_data(client,
 311                 bq20z75_data[REG_SERIAL_NUMBER].addr);
 312         if (ret < 0)
 313                 return ret;
 314
 315         ret = sprintf(bq20z75_serial, "%04x", ret);
 316         val->strval = bq20z75_serial;
 317
 318         return 0;
 319 }
 320
 321 static int bq20z75_get_property(struct power_supply *psy,
 322         enum power_supply_property psp,
 323         union power_supply_propval *val)
 324 {
 325         int count;
 326         int ret;
 327         struct bq20z75_info *bq20z75_device = container_of(psy,
 328                                 struct bq20z75_info, power_supply);
 329         struct i2c_client *client = bq20z75_device->client;
 330
 331         switch (psp) {
 332         case POWER_SUPPLY_PROP_PRESENT:
 333         case POWER_SUPPLY_PROP_HEALTH:
 334                 ret = bq20z75_get_battery_presence_and_health(client, psp, val);
 335                 if (ret)
 336                         return ret;
 337                 break;
 338
 339         case POWER_SUPPLY_PROP_TECHNOLOGY:
 340                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 341                 break;
 342
 343         case POWER_SUPPLY_PROP_ENERGY_NOW:
 344         case POWER_SUPPLY_PROP_ENERGY_FULL:
 345         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 346         case POWER_SUPPLY_PROP_CAPACITY:
 347                 for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
 348                         if (psp == bq20z75_data[count].psp)
 349                                 break;
 350                 }
 351
 352                 ret = bq20z75_get_battery_capacity(client, count, psp, val);
 353                 if (ret)
 354                         return ret;
 355
 356                 break;
 357
 358         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 359                 ret = bq20z75_get_battery_serial_number(client, val);
 360                 if (ret)
 361                         return ret;
 362                 break;
 363
 364         case POWER_SUPPLY_PROP_STATUS:
 365         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 366         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 367         case POWER_SUPPLY_PROP_CURRENT_NOW:
 368         case POWER_SUPPLY_PROP_TEMP:
 369         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 370         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 371         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 372                 for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
 373                         if (psp == bq20z75_data[count].psp)
 374                                 break;
 375                 }
 376
 377                 ret = bq20z75_get_battery_property(client, count, psp, val);
 378                 if (ret)
 379                         return ret;
 380
 381                 break;
 382
 383         default:
 384                 dev_err(&client->dev,
 385                         "%s: INVALID property\n", __func__);
 386                 return -EINVAL;
 387         }
 388
 389         /* Convert units to match requirements for power supply class */
 390         bq20z75_unit_adjustment(client, psp, val);
 391
 392         dev_dbg(&client->dev,
 393                 "%s: property = %d, value = %d\n", __func__, psp, val->intval);
 394
 395         return 0;
 396 }
 397
 398 static int bq20z75_probe(struct i2c_client *client,
 399         const struct i2c_device_id *id)
 400 {
 401         struct bq20z75_info *bq20z75_device;
 402         int rc;
 403
 404         bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
 405         if (!bq20z75_device)
 406                 return -ENOMEM;
 407
 408         bq20z75_device->client = client;
 409         bq20z75_device->power_supply.name = "battery";
 410         bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
 411         bq20z75_device->power_supply.properties = bq20z75_properties;
 412         bq20z75_device->power_supply.num_properties =
 413                 ARRAY_SIZE(bq20z75_properties);
 414         bq20z75_device->power_supply.get_property = bq20z75_get_property;
 415
 416         i2c_set_clientdata(client, bq20z75_device);
 417
 418         rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
 419         if (rc) {
 420                 dev_err(&client->dev,
 421                         "%s: Failed to register power supply\n", __func__);
 422                 kfree(bq20z75_device);
 423                 return rc;
 424         }
 425
 426         dev_info(&client->dev,
 427                 "%s: battery gas gauge device registered\n", client->name);
 428
 429         return 0;
 430 }
 431
 432 static int bq20z75_remove(struct i2c_client *client)
 433 {
 434         struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
 435
 436         power_supply_unregister(&bq20z75_device->power_supply);
 437         kfree(bq20z75_device);
 438         bq20z75_device = NULL;
 439
 440         return 0;
 441 }
 442
 443 #if defined CONFIG_PM
 444 static int bq20z75_suspend(struct i2c_client *client,
 445         pm_message_t state)
 446 {
 447         s32 ret;
 448
 449         /* write to manufacturer access with sleep command */
 450         ret = bq20z75_write_word_data(client,
 451                 bq20z75_data[REG_MANUFACTURER_DATA].addr,
 452                 MANUFACTURER_ACCESS_SLEEP);
 453         if (ret < 0)
 454                 return ret;
 455
 456         return 0;
 457 }
 458 #else
 459 #define bq20z75_suspend         NULL
 460 #endif
 461 /* any smbus transaction will wake up bq20z75 */
 462 #define bq20z75_resume          NULL
 463
 464 static const struct i2c_device_id bq20z75_id[] = {
 465         { "bq20z75", 0 },
 466         {}
 467 };
 468
 469 static struct i2c_driver bq20z75_battery_driver = {
 470         .probe          = bq20z75_probe,
 471         .remove         = bq20z75_remove,
 472         .suspend        = bq20z75_suspend,
 473         .resume         = bq20z75_resume,
 474         .id_table       = bq20z75_id,
 475         .driver = {
 476                 .name   = "bq20z75-battery",
 477         },
 478 };
 479
 480 static int __init bq20z75_battery_init(void)
 481 {
 482         return i2c_add_driver(&bq20z75_battery_driver);
 483 }
 484 module_init(bq20z75_battery_init);
 485
 486 static void __exit bq20z75_battery_exit(void)
 487 {
 488         i2c_del_driver(&bq20z75_battery_driver);
 489 }
 490 module_exit(bq20z75_battery_exit);
 491
 492 MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
 493 MODULE_LICENSE("GPL");