Pileus Git - ~andy/linux/blob - drivers/power/bq27x00_battery.c

   1 /*
   2  * BQ27x00 battery driver
   3  *
   4  * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
   5  * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
   6  * Copyright (C) 2010-2011 Lars-Peter Clausen <lars@metafoo.de>
   7  * Copyright (C) 2011 Pali Rohár <pali.rohar@gmail.com>
   8  *
   9  * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
  10  *
  11  * This package is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  *
  19  */
  20
  21 /*
  22  * Datasheets:
  23  * http://focus.ti.com/docs/prod/folders/print/bq27000.html
  24  * http://focus.ti.com/docs/prod/folders/print/bq27500.html
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/param.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/delay.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/power_supply.h>
  34 #include <linux/idr.h>
  35 #include <linux/i2c.h>
  36 #include <linux/slab.h>
  37 #include <asm/unaligned.h>
  38
  39 #include <linux/power/bq27x00_battery.h>
  40
  41 #define DRIVER_VERSION                  "1.2.0"
  42
  43 #define BQ27x00_REG_TEMP                0x06
  44 #define BQ27x00_REG_VOLT                0x08
  45 #define BQ27x00_REG_AI                  0x14
  46 #define BQ27x00_REG_FLAGS               0x0A
  47 #define BQ27x00_REG_TTE                 0x16
  48 #define BQ27x00_REG_TTF                 0x18
  49 #define BQ27x00_REG_TTECP               0x26
  50 #define BQ27x00_REG_NAC                 0x0C /* Nominal available capaciy */
  51 #define BQ27x00_REG_LMD                 0x12 /* Last measured discharge */
  52 #define BQ27x00_REG_CYCT                0x2A /* Cycle count total */
  53 #define BQ27x00_REG_AE                  0x22 /* Available enery */
  54
  55 #define BQ27000_REG_RSOC                0x0B /* Relative State-of-Charge */
  56 #define BQ27000_REG_ILMD                0x76 /* Initial last measured discharge */
  57 #define BQ27000_FLAG_EDVF               BIT(0) /* Final End-of-Discharge-Voltage flag */
  58 #define BQ27000_FLAG_EDV1               BIT(1) /* First End-of-Discharge-Voltage flag */
  59 #define BQ27000_FLAG_CI                 BIT(4) /* Capacity Inaccurate flag */
  60 #define BQ27000_FLAG_FC                 BIT(5)
  61 #define BQ27000_FLAG_CHGS               BIT(7) /* Charge state flag */
  62
  63 #define BQ27500_REG_SOC                 0x2C
  64 #define BQ27500_REG_DCAP                0x3C /* Design capacity */
  65 #define BQ27500_FLAG_DSG                BIT(0) /* Discharging */
  66 #define BQ27500_FLAG_SOCF               BIT(1) /* State-of-Charge threshold final */
  67 #define BQ27500_FLAG_SOC1               BIT(2) /* State-of-Charge threshold 1 */
  68 #define BQ27500_FLAG_CHG                BIT(8) /* Charging */
  69 #define BQ27500_FLAG_FC                 BIT(9) /* Fully charged */
  70
  71 #define BQ27000_RS                      20 /* Resistor sense */
  72
  73 struct bq27x00_device_info;
  74 struct bq27x00_access_methods {
  75         int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
  76 };
  77
  78 enum bq27x00_chip { BQ27000, BQ27500 };
  79
  80 struct bq27x00_reg_cache {
  81         int temperature;
  82         int time_to_empty;
  83         int time_to_empty_avg;
  84         int time_to_full;
  85         int charge_full;
  86         int cycle_count;
  87         int capacity;
  88         int energy;
  89         int flags;
  90 };
  91
  92 struct bq27x00_device_info {
  93         struct device           *dev;
  94         int                     id;
  95         enum bq27x00_chip       chip;
  96
  97         struct bq27x00_reg_cache cache;
  98         int charge_design_full;
  99
 100         unsigned long last_update;
 101         struct delayed_work work;
 102
 103         struct power_supply     bat;
 104
 105         struct bq27x00_access_methods bus;
 106
 107         struct mutex lock;
 108 };
 109
 110 static enum power_supply_property bq27x00_battery_props[] = {
 111         POWER_SUPPLY_PROP_STATUS,
 112         POWER_SUPPLY_PROP_PRESENT,
 113         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 114         POWER_SUPPLY_PROP_CURRENT_NOW,
 115         POWER_SUPPLY_PROP_CAPACITY,
 116         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 117         POWER_SUPPLY_PROP_TEMP,
 118         POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
 119         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
 120         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
 121         POWER_SUPPLY_PROP_TECHNOLOGY,
 122         POWER_SUPPLY_PROP_CHARGE_FULL,
 123         POWER_SUPPLY_PROP_CHARGE_NOW,
 124         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 125         POWER_SUPPLY_PROP_CYCLE_COUNT,
 126         POWER_SUPPLY_PROP_ENERGY_NOW,
 127 };
 128
 129 static unsigned int poll_interval = 360;
 130 module_param(poll_interval, uint, 0644);
 131 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
 132                                 "0 disables polling");
 133
 134 /*
 135  * Common code for BQ27x00 devices
 136  */
 137
 138 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
 139                 bool single)
 140 {
 141         return di->bus.read(di, reg, single);
 142 }
 143
 144 /*
 145  * Return the battery Relative State-of-Charge
 146  * Or < 0 if something fails.
 147  */
 148 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
 149 {
 150         int rsoc;
 151
 152         if (di->chip == BQ27500)
 153                 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
 154         else
 155                 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
 156
 157         if (rsoc < 0)
 158                 dev_dbg(di->dev, "error reading relative State-of-Charge\n");
 159
 160         return rsoc;
 161 }
 162
 163 /*
 164  * Return a battery charge value in µAh
 165  * Or < 0 if something fails.
 166  */
 167 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
 168 {
 169         int charge;
 170
 171         charge = bq27x00_read(di, reg, false);
 172         if (charge < 0) {
 173                 dev_dbg(di->dev, "error reading charge register %02x: %d\n",
 174                         reg, charge);
 175                 return charge;
 176         }
 177
 178         if (di->chip == BQ27500)
 179                 charge *= 1000;
 180         else
 181                 charge = charge * 3570 / BQ27000_RS;
 182
 183         return charge;
 184 }
 185
 186 /*
 187  * Return the battery Nominal available capaciy in µAh
 188  * Or < 0 if something fails.
 189  */
 190 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
 191 {
 192         return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
 193 }
 194
 195 /*
 196  * Return the battery Last measured discharge in µAh
 197  * Or < 0 if something fails.
 198  */
 199 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
 200 {
 201         return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
 202 }
 203
 204 /*
 205  * Return the battery Initial last measured discharge in µAh
 206  * Or < 0 if something fails.
 207  */
 208 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
 209 {
 210         int ilmd;
 211
 212         if (di->chip == BQ27500)
 213                 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
 214         else
 215                 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
 216
 217         if (ilmd < 0) {
 218                 dev_dbg(di->dev, "error reading initial last measured discharge\n");
 219                 return ilmd;
 220         }
 221
 222         if (di->chip == BQ27500)
 223                 ilmd *= 1000;
 224         else
 225                 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
 226
 227         return ilmd;
 228 }
 229
 230 /*
 231  * Return the battery Available energy in µWh
 232  * Or < 0 if something fails.
 233  */
 234 static int bq27x00_battery_read_energy(struct bq27x00_device_info *di)
 235 {
 236         int ae;
 237
 238         ae = bq27x00_read(di, BQ27x00_REG_AE, false);
 239         if (ae < 0) {
 240                 dev_dbg(di->dev, "error reading available energy\n");
 241                 return ae;
 242         }
 243
 244         if (di->chip == BQ27500)
 245                 ae *= 1000;
 246         else
 247                 ae = ae * 29200 / BQ27000_RS;
 248
 249         return ae;
 250 }
 251
 252 /*
 253  * Return the battery temperature in tenths of degree Celsius
 254  * Or < 0 if something fails.
 255  */
 256 static int bq27x00_battery_read_temperature(struct bq27x00_device_info *di)
 257 {
 258         int temp;
 259
 260         temp = bq27x00_read(di, BQ27x00_REG_TEMP, false);
 261         if (temp < 0) {
 262                 dev_err(di->dev, "error reading temperature\n");
 263                 return temp;
 264         }
 265
 266         if (di->chip == BQ27500)
 267                 temp -= 2731;
 268         else
 269                 temp = ((temp * 5) - 5463) / 2;
 270
 271         return temp;
 272 }
 273
 274 /*
 275  * Return the battery Cycle count total
 276  * Or < 0 if something fails.
 277  */
 278 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
 279 {
 280         int cyct;
 281
 282         cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
 283         if (cyct < 0)
 284                 dev_err(di->dev, "error reading cycle count total\n");
 285
 286         return cyct;
 287 }
 288
 289 /*
 290  * Read a time register.
 291  * Return < 0 if something fails.
 292  */
 293 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
 294 {
 295         int tval;
 296
 297         tval = bq27x00_read(di, reg, false);
 298         if (tval < 0) {
 299                 dev_dbg(di->dev, "error reading time register %02x: %d\n",
 300                         reg, tval);
 301                 return tval;
 302         }
 303
 304         if (tval == 65535)
 305                 return -ENODATA;
 306
 307         return tval * 60;
 308 }
 309
 310 static void bq27x00_update(struct bq27x00_device_info *di)
 311 {
 312         struct bq27x00_reg_cache cache = {0, };
 313         bool is_bq27500 = di->chip == BQ27500;
 314
 315         cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
 316         if (cache.flags >= 0) {
 317                 if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {
 318                         dev_info(di->dev, "battery is not calibrated! ignoring capacity values\n");
 319                         cache.capacity = -ENODATA;
 320                         cache.energy = -ENODATA;
 321                         cache.time_to_empty = -ENODATA;
 322                         cache.time_to_empty_avg = -ENODATA;
 323                         cache.time_to_full = -ENODATA;
 324                         cache.charge_full = -ENODATA;
 325                 } else {
 326                         cache.capacity = bq27x00_battery_read_rsoc(di);
 327                         cache.energy = bq27x00_battery_read_energy(di);
 328                         cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
 329                         cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
 330                         cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
 331                         cache.charge_full = bq27x00_battery_read_lmd(di);
 332                 }
 333                 cache.temperature = bq27x00_battery_read_temperature(di);
 334                 cache.cycle_count = bq27x00_battery_read_cyct(di);
 335
 336                 /* We only have to read charge design full once */
 337                 if (di->charge_design_full <= 0)
 338                         di->charge_design_full = bq27x00_battery_read_ilmd(di);
 339         }
 340
 341         if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {
 342                 di->cache = cache;
 343                 power_supply_changed(&di->bat);
 344         }
 345
 346         di->last_update = jiffies;
 347 }
 348
 349 static void bq27x00_battery_poll(struct work_struct *work)
 350 {
 351         struct bq27x00_device_info *di =
 352                 container_of(work, struct bq27x00_device_info, work.work);
 353
 354         bq27x00_update(di);
 355
 356         if (poll_interval > 0) {
 357                 /* The timer does not have to be accurate. */
 358                 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
 359                 schedule_delayed_work(&di->work, poll_interval * HZ);
 360         }
 361 }
 362
 363 /*
 364  * Return the battery average current in µA
 365  * Note that current can be negative signed as well
 366  * Or 0 if something fails.
 367  */
 368 static int bq27x00_battery_current(struct bq27x00_device_info *di,
 369         union power_supply_propval *val)
 370 {
 371         int curr;
 372         int flags;
 373
 374         curr = bq27x00_read(di, BQ27x00_REG_AI, false);
 375         if (curr < 0) {
 376                 dev_err(di->dev, "error reading current\n");
 377                 return curr;
 378         }
 379
 380         if (di->chip == BQ27500) {
 381                 /* bq27500 returns signed value */
 382                 val->intval = (int)((s16)curr) * 1000;
 383         } else {
 384                 flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
 385                 if (flags & BQ27000_FLAG_CHGS) {
 386                         dev_dbg(di->dev, "negative current!\n");
 387                         curr = -curr;
 388                 }
 389
 390                 val->intval = curr * 3570 / BQ27000_RS;
 391         }
 392
 393         return 0;
 394 }
 395
 396 static int bq27x00_battery_status(struct bq27x00_device_info *di,
 397         union power_supply_propval *val)
 398 {
 399         int status;
 400
 401         if (di->chip == BQ27500) {
 402                 if (di->cache.flags & BQ27500_FLAG_FC)
 403                         status = POWER_SUPPLY_STATUS_FULL;
 404                 else if (di->cache.flags & BQ27500_FLAG_DSG)
 405                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 406                 else if (di->cache.flags & BQ27500_FLAG_CHG)
 407                         status = POWER_SUPPLY_STATUS_CHARGING;
 408                 else if (power_supply_am_i_supplied(&di->bat))
 409                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 410                 else
 411                         status = POWER_SUPPLY_STATUS_UNKNOWN;
 412         } else {
 413                 if (di->cache.flags & BQ27000_FLAG_FC)
 414                         status = POWER_SUPPLY_STATUS_FULL;
 415                 else if (di->cache.flags & BQ27000_FLAG_CHGS)
 416                         status = POWER_SUPPLY_STATUS_CHARGING;
 417                 else if (power_supply_am_i_supplied(&di->bat))
 418                         status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 419                 else
 420                         status = POWER_SUPPLY_STATUS_DISCHARGING;
 421         }
 422
 423         val->intval = status;
 424
 425         return 0;
 426 }
 427
 428 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
 429         union power_supply_propval *val)
 430 {
 431         int level;
 432
 433         if (di->chip == BQ27500) {
 434                 if (di->cache.flags & BQ27500_FLAG_FC)
 435                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 436                 else if (di->cache.flags & BQ27500_FLAG_SOC1)
 437                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 438                 else if (di->cache.flags & BQ27500_FLAG_SOCF)
 439                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 440                 else
 441                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 442         } else {
 443                 if (di->cache.flags & BQ27000_FLAG_FC)
 444                         level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 445                 else if (di->cache.flags & BQ27000_FLAG_EDV1)
 446                         level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 447                 else if (di->cache.flags & BQ27000_FLAG_EDVF)
 448                         level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 449                 else
 450                         level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 451         }
 452
 453         val->intval = level;
 454
 455         return 0;
 456 }
 457
 458 /*
 459  * Return the battery Voltage in milivolts
 460  * Or < 0 if something fails.
 461  */
 462 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
 463         union power_supply_propval *val)
 464 {
 465         int volt;
 466
 467         volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
 468         if (volt < 0) {
 469                 dev_err(di->dev, "error reading voltage\n");
 470                 return volt;
 471         }
 472
 473         val->intval = volt * 1000;
 474
 475         return 0;
 476 }
 477
 478 static int bq27x00_simple_value(int value,
 479         union power_supply_propval *val)
 480 {
 481         if (value < 0)
 482                 return value;
 483
 484         val->intval = value;
 485
 486         return 0;
 487 }
 488
 489 #define to_bq27x00_device_info(x) container_of((x), \
 490                                 struct bq27x00_device_info, bat);
 491
 492 static int bq27x00_battery_get_property(struct power_supply *psy,
 493                                         enum power_supply_property psp,
 494                                         union power_supply_propval *val)
 495 {
 496         int ret = 0;
 497         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 498
 499         mutex_lock(&di->lock);
 500         if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
 501                 cancel_delayed_work_sync(&di->work);
 502                 bq27x00_battery_poll(&di->work.work);
 503         }
 504         mutex_unlock(&di->lock);
 505
 506         if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
 507                 return -ENODEV;
 508
 509         switch (psp) {
 510         case POWER_SUPPLY_PROP_STATUS:
 511                 ret = bq27x00_battery_status(di, val);
 512                 break;
 513         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 514                 ret = bq27x00_battery_voltage(di, val);
 515                 break;
 516         case POWER_SUPPLY_PROP_PRESENT:
 517                 val->intval = di->cache.flags < 0 ? 0 : 1;
 518                 break;
 519         case POWER_SUPPLY_PROP_CURRENT_NOW:
 520                 ret = bq27x00_battery_current(di, val);
 521                 break;
 522         case POWER_SUPPLY_PROP_CAPACITY:
 523                 ret = bq27x00_simple_value(di->cache.capacity, val);
 524                 break;
 525         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 526                 ret = bq27x00_battery_capacity_level(di, val);
 527                 break;
 528         case POWER_SUPPLY_PROP_TEMP:
 529                 ret = bq27x00_simple_value(di->cache.temperature, val);
 530                 break;
 531         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 532                 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
 533                 break;
 534         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 535                 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
 536                 break;
 537         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 538                 ret = bq27x00_simple_value(di->cache.time_to_full, val);
 539                 break;
 540         case POWER_SUPPLY_PROP_TECHNOLOGY:
 541                 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 542                 break;
 543         case POWER_SUPPLY_PROP_CHARGE_NOW:
 544                 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
 545                 break;
 546         case POWER_SUPPLY_PROP_CHARGE_FULL:
 547                 ret = bq27x00_simple_value(di->cache.charge_full, val);
 548                 break;
 549         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 550                 ret = bq27x00_simple_value(di->charge_design_full, val);
 551                 break;
 552         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 553                 ret = bq27x00_simple_value(di->cache.cycle_count, val);
 554                 break;
 555         case POWER_SUPPLY_PROP_ENERGY_NOW:
 556                 ret = bq27x00_simple_value(di->cache.energy, val);
 557                 break;
 558         default:
 559                 return -EINVAL;
 560         }
 561
 562         return ret;
 563 }
 564
 565 static void bq27x00_external_power_changed(struct power_supply *psy)
 566 {
 567         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 568
 569         cancel_delayed_work_sync(&di->work);
 570         schedule_delayed_work(&di->work, 0);
 571 }
 572
 573 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
 574 {
 575         int ret;
 576
 577         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 578         di->bat.properties = bq27x00_battery_props;
 579         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 580         di->bat.get_property = bq27x00_battery_get_property;
 581         di->bat.external_power_changed = bq27x00_external_power_changed;
 582
 583         INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
 584         mutex_init(&di->lock);
 585
 586         ret = power_supply_register(di->dev, &di->bat);
 587         if (ret) {
 588                 dev_err(di->dev, "failed to register battery: %d\n", ret);
 589                 return ret;
 590         }
 591
 592         dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 593
 594         bq27x00_update(di);
 595
 596         return 0;
 597 }
 598
 599 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
 600 {
 601         /*
 602          * power_supply_unregister call bq27x00_battery_get_property which
 603          * call bq27x00_battery_poll.
 604          * Make sure that bq27x00_battery_poll will not call
 605          * schedule_delayed_work again after unregister (which cause OOPS).
 606          */
 607         poll_interval = 0;
 608
 609         cancel_delayed_work_sync(&di->work);
 610
 611         power_supply_unregister(&di->bat);
 612
 613         mutex_destroy(&di->lock);
 614 }
 615
 616
 617 /* i2c specific code */
 618 #ifdef CONFIG_BATTERY_BQ27X00_I2C
 619
 620 /* If the system has several batteries we need a different name for each
 621  * of them...
 622  */
 623 static DEFINE_IDR(battery_id);
 624 static DEFINE_MUTEX(battery_mutex);
 625
 626 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
 627 {
 628         struct i2c_client *client = to_i2c_client(di->dev);
 629         struct i2c_msg msg[2];
 630         unsigned char data[2];
 631         int ret;
 632
 633         if (!client->adapter)
 634                 return -ENODEV;
 635
 636         msg[0].addr = client->addr;
 637         msg[0].flags = 0;
 638         msg[0].buf = &reg;
 639         msg[0].len = sizeof(reg);
 640         msg[1].addr = client->addr;
 641         msg[1].flags = I2C_M_RD;
 642         msg[1].buf = data;
 643         if (single)
 644                 msg[1].len = 1;
 645         else
 646                 msg[1].len = 2;
 647
 648         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 649         if (ret < 0)
 650                 return ret;
 651
 652         if (!single)
 653                 ret = get_unaligned_le16(data);
 654         else
 655                 ret = data[0];
 656
 657         return ret;
 658 }
 659
 660 static int bq27x00_battery_probe(struct i2c_client *client,
 661                                  const struct i2c_device_id *id)
 662 {
 663         char *name;
 664         struct bq27x00_device_info *di;
 665         int num;
 666         int retval = 0;
 667
 668         /* Get new ID for the new battery device */
 669         retval = idr_pre_get(&battery_id, GFP_KERNEL);
 670         if (retval == 0)
 671                 return -ENOMEM;
 672         mutex_lock(&battery_mutex);
 673         retval = idr_get_new(&battery_id, client, &num);
 674         mutex_unlock(&battery_mutex);
 675         if (retval < 0)
 676                 return retval;
 677
 678         name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
 679         if (!name) {
 680                 dev_err(&client->dev, "failed to allocate device name\n");
 681                 retval = -ENOMEM;
 682                 goto batt_failed_1;
 683         }
 684
 685         di = kzalloc(sizeof(*di), GFP_KERNEL);
 686         if (!di) {
 687                 dev_err(&client->dev, "failed to allocate device info data\n");
 688                 retval = -ENOMEM;
 689                 goto batt_failed_2;
 690         }
 691
 692         di->id = num;
 693         di->dev = &client->dev;
 694         di->chip = id->driver_data;
 695         di->bat.name = name;
 696         di->bus.read = &bq27x00_read_i2c;
 697
 698         if (bq27x00_powersupply_init(di))
 699                 goto batt_failed_3;
 700
 701         i2c_set_clientdata(client, di);
 702
 703         return 0;
 704
 705 batt_failed_3:
 706         kfree(di);
 707 batt_failed_2:
 708         kfree(name);
 709 batt_failed_1:
 710         mutex_lock(&battery_mutex);
 711         idr_remove(&battery_id, num);
 712         mutex_unlock(&battery_mutex);
 713
 714         return retval;
 715 }
 716
 717 static int bq27x00_battery_remove(struct i2c_client *client)
 718 {
 719         struct bq27x00_device_info *di = i2c_get_clientdata(client);
 720
 721         bq27x00_powersupply_unregister(di);
 722
 723         kfree(di->bat.name);
 724
 725         mutex_lock(&battery_mutex);
 726         idr_remove(&battery_id, di->id);
 727         mutex_unlock(&battery_mutex);
 728
 729         kfree(di);
 730
 731         return 0;
 732 }
 733
 734 static const struct i2c_device_id bq27x00_id[] = {
 735         { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
 736         { "bq27500", BQ27500 },
 737         {},
 738 };
 739 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
 740
 741 static struct i2c_driver bq27x00_battery_driver = {
 742         .driver = {
 743                 .name = "bq27x00-battery",
 744         },
 745         .probe = bq27x00_battery_probe,
 746         .remove = bq27x00_battery_remove,
 747         .id_table = bq27x00_id,
 748 };
 749
 750 static inline int bq27x00_battery_i2c_init(void)
 751 {
 752         int ret = i2c_add_driver(&bq27x00_battery_driver);
 753         if (ret)
 754                 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
 755
 756         return ret;
 757 }
 758
 759 static inline void bq27x00_battery_i2c_exit(void)
 760 {
 761         i2c_del_driver(&bq27x00_battery_driver);
 762 }
 763
 764 #else
 765
 766 static inline int bq27x00_battery_i2c_init(void) { return 0; }
 767 static inline void bq27x00_battery_i2c_exit(void) {};
 768
 769 #endif
 770
 771 /* platform specific code */
 772 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
 773
 774 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
 775                         bool single)
 776 {
 777         struct device *dev = di->dev;
 778         struct bq27000_platform_data *pdata = dev->platform_data;
 779         unsigned int timeout = 3;
 780         int upper, lower;
 781         int temp;
 782
 783         if (!single) {
 784                 /* Make sure the value has not changed in between reading the
 785                  * lower and the upper part */
 786                 upper = pdata->read(dev, reg + 1);
 787                 do {
 788                         temp = upper;
 789                         if (upper < 0)
 790                                 return upper;
 791
 792                         lower = pdata->read(dev, reg);
 793                         if (lower < 0)
 794                                 return lower;
 795
 796                         upper = pdata->read(dev, reg + 1);
 797                 } while (temp != upper && --timeout);
 798
 799                 if (timeout == 0)
 800                         return -EIO;
 801
 802                 return (upper << 8) | lower;
 803         }
 804
 805         return pdata->read(dev, reg);
 806 }
 807
 808 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
 809 {
 810         struct bq27x00_device_info *di;
 811         struct bq27000_platform_data *pdata = pdev->dev.platform_data;
 812         int ret;
 813
 814         if (!pdata) {
 815                 dev_err(&pdev->dev, "no platform_data supplied\n");
 816                 return -EINVAL;
 817         }
 818
 819         if (!pdata->read) {
 820                 dev_err(&pdev->dev, "no hdq read callback supplied\n");
 821                 return -EINVAL;
 822         }
 823
 824         di = kzalloc(sizeof(*di), GFP_KERNEL);
 825         if (!di) {
 826                 dev_err(&pdev->dev, "failed to allocate device info data\n");
 827                 return -ENOMEM;
 828         }
 829
 830         platform_set_drvdata(pdev, di);
 831
 832         di->dev = &pdev->dev;
 833         di->chip = BQ27000;
 834
 835         di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 836         di->bus.read = &bq27000_read_platform;
 837
 838         ret = bq27x00_powersupply_init(di);
 839         if (ret)
 840                 goto err_free;
 841
 842         return 0;
 843
 844 err_free:
 845         platform_set_drvdata(pdev, NULL);
 846         kfree(di);
 847
 848         return ret;
 849 }
 850
 851 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
 852 {
 853         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 854
 855         bq27x00_powersupply_unregister(di);
 856
 857         platform_set_drvdata(pdev, NULL);
 858         kfree(di);
 859
 860         return 0;
 861 }
 862
 863 static struct platform_driver bq27000_battery_driver = {
 864         .probe  = bq27000_battery_probe,
 865         .remove = __devexit_p(bq27000_battery_remove),
 866         .driver = {
 867                 .name = "bq27000-battery",
 868                 .owner = THIS_MODULE,
 869         },
 870 };
 871
 872 static inline int bq27x00_battery_platform_init(void)
 873 {
 874         int ret = platform_driver_register(&bq27000_battery_driver);
 875         if (ret)
 876                 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
 877
 878         return ret;
 879 }
 880
 881 static inline void bq27x00_battery_platform_exit(void)
 882 {
 883         platform_driver_unregister(&bq27000_battery_driver);
 884 }
 885
 886 #else
 887
 888 static inline int bq27x00_battery_platform_init(void) { return 0; }
 889 static inline void bq27x00_battery_platform_exit(void) {};
 890
 891 #endif
 892
 893 /*
 894  * Module stuff
 895  */
 896
 897 static int __init bq27x00_battery_init(void)
 898 {
 899         int ret;
 900
 901         ret = bq27x00_battery_i2c_init();
 902         if (ret)
 903                 return ret;
 904
 905         ret = bq27x00_battery_platform_init();
 906         if (ret)
 907                 bq27x00_battery_i2c_exit();
 908
 909         return ret;
 910 }
 911 module_init(bq27x00_battery_init);
 912
 913 static void __exit bq27x00_battery_exit(void)
 914 {
 915         bq27x00_battery_platform_exit();
 916         bq27x00_battery_i2c_exit();
 917 }
 918 module_exit(bq27x00_battery_exit);
 919
 920 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 921 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
 922 MODULE_LICENSE("GPL");