drivers/acpi/battery.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  battery.c - ACPI Battery Driver (Revision: 2.0)
   4  *
   5  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
   6  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  */
  10
  11 #define pr_fmt(fmt) "ACPI: battery: " fmt
  12
  13 #include <linux/async.h>
  14 #include <linux/delay.h>
  15 #include <linux/dmi.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/kernel.h>
  18 #include <linux/list.h>
  19 #include <linux/module.h>
  20 #include <linux/mutex.h>
  21 #include <linux/slab.h>
  22 #include <linux/suspend.h>
  23 #include <linux/types.h>
  24
  25 #include <asm/unaligned.h>
  26
  27 #include <linux/acpi.h>
  28 #include <linux/power_supply.h>
  29
  30 #include <acpi/battery.h>
  31
  32 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
  33 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
  34         ((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
  35
  36 #define ACPI_BATTERY_DEVICE_NAME        "Battery"
  37
  38 /* Battery power unit: 0 means mW, 1 means mA */
  39 #define ACPI_BATTERY_POWER_UNIT_MA      1
  40
  41 #define ACPI_BATTERY_STATE_DISCHARGING  0x1
  42 #define ACPI_BATTERY_STATE_CHARGING     0x2
  43 #define ACPI_BATTERY_STATE_CRITICAL     0x4
  44
  45 MODULE_AUTHOR("Paul Diefenbaugh");
  46 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
  47 MODULE_DESCRIPTION("ACPI Battery Driver");
  48 MODULE_LICENSE("GPL");
  49
  50 static async_cookie_t async_cookie;
  51 static bool battery_driver_registered;
  52 static int battery_bix_broken_package;
  53 static int battery_notification_delay_ms;
  54 static int battery_ac_is_broken;
  55 static int battery_quirk_notcharging;
  56 static unsigned int cache_time = 1000;
  57 module_param(cache_time, uint, 0644);
  58 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  59
  60 static const struct acpi_device_id battery_device_ids[] = {
  61         {"PNP0C0A", 0},
  62         {"", 0},
  63 };
  64
  65 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
  66
  67 enum {
  68         ACPI_BATTERY_ALARM_PRESENT,
  69         ACPI_BATTERY_XINFO_PRESENT,
  70         ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
  71         /* On Lenovo Thinkpad models from 2010 and 2011, the power unit
  72          * switches between mWh and mAh depending on whether the system
  73          * is running on battery or not.  When mAh is the unit, most
  74          * reported values are incorrect and need to be adjusted by
  75          * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
  76          * Pre-2010 and 2012 models appear to always report in mWh and
  77          * are thus unaffected (tested with t42, t61, t500, x200, x300,
  78          * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
  79          *  the 2011 models that fixes the issue (tested on x220 with a
  80          * post-1.29 BIOS), but as of Nov. 2012, no such update is
  81          * available for the 2010 models.
  82          */
  83         ACPI_BATTERY_QUIRK_THINKPAD_MAH,
  84         /* for batteries reporting current capacity with design capacity
  85          * on a full charge, but showing degradation in full charge cap.
  86          */
  87         ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
  88 };
  89
  90 struct acpi_battery {
  91         struct mutex lock;
  92         struct mutex sysfs_lock;
  93         struct power_supply *bat;
  94         struct power_supply_desc bat_desc;
  95         struct acpi_device *device;
  96         struct notifier_block pm_nb;
  97         struct list_head list;
  98         unsigned long update_time;
  99         int revision;
 100         int rate_now;
 101         int capacity_now;
 102         int voltage_now;
 103         int design_capacity;
 104         int full_charge_capacity;
 105         int technology;
 106         int design_voltage;
 107         int design_capacity_warning;
 108         int design_capacity_low;
 109         int cycle_count;
 110         int measurement_accuracy;
 111         int max_sampling_time;
 112         int min_sampling_time;
 113         int max_averaging_interval;
 114         int min_averaging_interval;
 115         int capacity_granularity_1;
 116         int capacity_granularity_2;
 117         int alarm;
 118         char model_number[32];
 119         char serial_number[32];
 120         char type[32];
 121         char oem_info[32];
 122         int state;
 123         int power_unit;
 124         unsigned long flags;
 125 };
 126
 127 #define to_acpi_battery(x) power_supply_get_drvdata(x)
 128
 129 static inline int acpi_battery_present(struct acpi_battery *battery)
 130 {
 131         return battery->device->status.battery_present;
 132 }
 133
 134 static int acpi_battery_technology(struct acpi_battery *battery)
 135 {
 136         if (!strcasecmp("NiCd", battery->type))
 137                 return POWER_SUPPLY_TECHNOLOGY_NiCd;
 138         if (!strcasecmp("NiMH", battery->type))
 139                 return POWER_SUPPLY_TECHNOLOGY_NiMH;
 140         if (!strcasecmp("LION", battery->type))
 141                 return POWER_SUPPLY_TECHNOLOGY_LION;
 142         if (!strncasecmp("LI-ION", battery->type, 6))
 143                 return POWER_SUPPLY_TECHNOLOGY_LION;
 144         if (!strcasecmp("LiP", battery->type))
 145                 return POWER_SUPPLY_TECHNOLOGY_LIPO;
 146         return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 147 }
 148
 149 static int acpi_battery_get_state(struct acpi_battery *battery);
 150
 151 static int acpi_battery_is_charged(struct acpi_battery *battery)
 152 {
 153         /* charging, discharging or critical low */
 154         if (battery->state != 0)
 155                 return 0;
 156
 157         /* battery not reporting charge */
 158         if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
 159             battery->capacity_now == 0)
 160                 return 0;
 161
 162         /* good batteries update full_charge as the batteries degrade */
 163         if (battery->full_charge_capacity == battery->capacity_now)
 164                 return 1;
 165
 166         /* fallback to using design values for broken batteries */
 167         if (battery->design_capacity <= battery->capacity_now)
 168                 return 1;
 169
 170         /* we don't do any sort of metric based on percentages */
 171         return 0;
 172 }
 173
 174 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
 175 {
 176         return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
 177                 ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
 178                 battery->full_charge_capacity < battery->design_capacity;
 179 }
 180
 181 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
 182 {
 183         /*
 184          * Some devices wrongly report discharging if the battery's charge level
 185          * was above the device's start charging threshold atm the AC adapter
 186          * was plugged in and the device thus did not start a new charge cycle.
 187          */
 188         if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
 189             battery->rate_now == 0)
 190                 return POWER_SUPPLY_STATUS_NOT_CHARGING;
 191
 192         return POWER_SUPPLY_STATUS_DISCHARGING;
 193 }
 194
 195 static int acpi_battery_get_property(struct power_supply *psy,
 196                                      enum power_supply_property psp,
 197                                      union power_supply_propval *val)
 198 {
 199         int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
 200         struct acpi_battery *battery = to_acpi_battery(psy);
 201
 202         if (acpi_battery_present(battery)) {
 203                 /* run battery update only if it is present */
 204                 acpi_battery_get_state(battery);
 205         } else if (psp != POWER_SUPPLY_PROP_PRESENT)
 206                 return -ENODEV;
 207         switch (psp) {
 208         case POWER_SUPPLY_PROP_STATUS:
 209                 if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
 210                         val->intval = acpi_battery_handle_discharging(battery);
 211                 else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
 212                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 213                 else if (acpi_battery_is_charged(battery))
 214                         val->intval = POWER_SUPPLY_STATUS_FULL;
 215                 else if (battery_quirk_notcharging)
 216                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 217                 else
 218                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 219                 break;
 220         case POWER_SUPPLY_PROP_PRESENT:
 221                 val->intval = acpi_battery_present(battery);
 222                 break;
 223         case POWER_SUPPLY_PROP_TECHNOLOGY:
 224                 val->intval = acpi_battery_technology(battery);
 225                 break;
 226         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 227                 val->intval = battery->cycle_count;
 228                 break;
 229         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 230                 if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 231                         ret = -ENODEV;
 232                 else
 233                         val->intval = battery->design_voltage * 1000;
 234                 break;
 235         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 236                 if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
 237                         ret = -ENODEV;
 238                 else
 239                         val->intval = battery->voltage_now * 1000;
 240                 break;
 241         case POWER_SUPPLY_PROP_CURRENT_NOW:
 242         case POWER_SUPPLY_PROP_POWER_NOW:
 243                 if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
 244                         ret = -ENODEV;
 245                 else
 246                         val->intval = battery->rate_now * 1000;
 247                 break;
 248         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 249         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 250                 if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 251                         ret = -ENODEV;
 252                 else
 253                         val->intval = battery->design_capacity * 1000;
 254                 break;
 255         case POWER_SUPPLY_PROP_CHARGE_FULL:
 256         case POWER_SUPPLY_PROP_ENERGY_FULL:
 257                 if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
 258                         ret = -ENODEV;
 259                 else
 260                         val->intval = battery->full_charge_capacity * 1000;
 261                 break;
 262         case POWER_SUPPLY_PROP_CHARGE_NOW:
 263         case POWER_SUPPLY_PROP_ENERGY_NOW:
 264                 if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
 265                         ret = -ENODEV;
 266                 else
 267                         val->intval = battery->capacity_now * 1000;
 268                 break;
 269         case POWER_SUPPLY_PROP_CAPACITY:
 270                 if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
 271                         full_capacity = battery->full_charge_capacity;
 272                 else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 273                         full_capacity = battery->design_capacity;
 274
 275                 if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
 276                     full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 277                         ret = -ENODEV;
 278                 else
 279                         val->intval = battery->capacity_now * 100/
 280                                         full_capacity;
 281                 break;
 282         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 283                 if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
 284                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 285                 else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
 286                         (battery->capacity_now <= battery->alarm))
 287                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 288                 else if (acpi_battery_is_charged(battery))
 289                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 290                 else
 291                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 292                 break;
 293         case POWER_SUPPLY_PROP_MODEL_NAME:
 294                 val->strval = battery->model_number;
 295                 break;
 296         case POWER_SUPPLY_PROP_MANUFACTURER:
 297                 val->strval = battery->oem_info;
 298                 break;
 299         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 300                 val->strval = battery->serial_number;
 301                 break;
 302         default:
 303                 ret = -EINVAL;
 304         }
 305         return ret;
 306 }
 307
 308 static enum power_supply_property charge_battery_props[] = {
 309         POWER_SUPPLY_PROP_STATUS,
 310         POWER_SUPPLY_PROP_PRESENT,
 311         POWER_SUPPLY_PROP_TECHNOLOGY,
 312         POWER_SUPPLY_PROP_CYCLE_COUNT,
 313         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 314         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 315         POWER_SUPPLY_PROP_CURRENT_NOW,
 316         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 317         POWER_SUPPLY_PROP_CHARGE_FULL,
 318         POWER_SUPPLY_PROP_CHARGE_NOW,
 319         POWER_SUPPLY_PROP_CAPACITY,
 320         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 321         POWER_SUPPLY_PROP_MODEL_NAME,
 322         POWER_SUPPLY_PROP_MANUFACTURER,
 323         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 324 };
 325
 326 static enum power_supply_property charge_battery_full_cap_broken_props[] = {
 327         POWER_SUPPLY_PROP_STATUS,
 328         POWER_SUPPLY_PROP_PRESENT,
 329         POWER_SUPPLY_PROP_TECHNOLOGY,
 330         POWER_SUPPLY_PROP_CYCLE_COUNT,
 331         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 332         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 333         POWER_SUPPLY_PROP_CURRENT_NOW,
 334         POWER_SUPPLY_PROP_CHARGE_NOW,
 335         POWER_SUPPLY_PROP_MODEL_NAME,
 336         POWER_SUPPLY_PROP_MANUFACTURER,
 337         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 338 };
 339
 340 static enum power_supply_property energy_battery_props[] = {
 341         POWER_SUPPLY_PROP_STATUS,
 342         POWER_SUPPLY_PROP_PRESENT,
 343         POWER_SUPPLY_PROP_TECHNOLOGY,
 344         POWER_SUPPLY_PROP_CYCLE_COUNT,
 345         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 346         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 347         POWER_SUPPLY_PROP_POWER_NOW,
 348         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 349         POWER_SUPPLY_PROP_ENERGY_FULL,
 350         POWER_SUPPLY_PROP_ENERGY_NOW,
 351         POWER_SUPPLY_PROP_CAPACITY,
 352         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 353         POWER_SUPPLY_PROP_MODEL_NAME,
 354         POWER_SUPPLY_PROP_MANUFACTURER,
 355         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 356 };
 357
 358 static enum power_supply_property energy_battery_full_cap_broken_props[] = {
 359         POWER_SUPPLY_PROP_STATUS,
 360         POWER_SUPPLY_PROP_PRESENT,
 361         POWER_SUPPLY_PROP_TECHNOLOGY,
 362         POWER_SUPPLY_PROP_CYCLE_COUNT,
 363         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 364         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 365         POWER_SUPPLY_PROP_POWER_NOW,
 366         POWER_SUPPLY_PROP_ENERGY_NOW,
 367         POWER_SUPPLY_PROP_MODEL_NAME,
 368         POWER_SUPPLY_PROP_MANUFACTURER,
 369         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 370 };
 371
 372 /* Battery Management */
 373 struct acpi_offsets {
 374         size_t offset;          /* offset inside struct acpi_sbs_battery */
 375         u8 mode;                /* int or string? */
 376 };
 377
 378 static const struct acpi_offsets state_offsets[] = {
 379         {offsetof(struct acpi_battery, state), 0},
 380         {offsetof(struct acpi_battery, rate_now), 0},
 381         {offsetof(struct acpi_battery, capacity_now), 0},
 382         {offsetof(struct acpi_battery, voltage_now), 0},
 383 };
 384
 385 static const struct acpi_offsets info_offsets[] = {
 386         {offsetof(struct acpi_battery, power_unit), 0},
 387         {offsetof(struct acpi_battery, design_capacity), 0},
 388         {offsetof(struct acpi_battery, full_charge_capacity), 0},
 389         {offsetof(struct acpi_battery, technology), 0},
 390         {offsetof(struct acpi_battery, design_voltage), 0},
 391         {offsetof(struct acpi_battery, design_capacity_warning), 0},
 392         {offsetof(struct acpi_battery, design_capacity_low), 0},
 393         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 394         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 395         {offsetof(struct acpi_battery, model_number), 1},
 396         {offsetof(struct acpi_battery, serial_number), 1},
 397         {offsetof(struct acpi_battery, type), 1},
 398         {offsetof(struct acpi_battery, oem_info), 1},
 399 };
 400
 401 static const struct acpi_offsets extended_info_offsets[] = {
 402         {offsetof(struct acpi_battery, revision), 0},
 403         {offsetof(struct acpi_battery, power_unit), 0},
 404         {offsetof(struct acpi_battery, design_capacity), 0},
 405         {offsetof(struct acpi_battery, full_charge_capacity), 0},
 406         {offsetof(struct acpi_battery, technology), 0},
 407         {offsetof(struct acpi_battery, design_voltage), 0},
 408         {offsetof(struct acpi_battery, design_capacity_warning), 0},
 409         {offsetof(struct acpi_battery, design_capacity_low), 0},
 410         {offsetof(struct acpi_battery, cycle_count), 0},
 411         {offsetof(struct acpi_battery, measurement_accuracy), 0},
 412         {offsetof(struct acpi_battery, max_sampling_time), 0},
 413         {offsetof(struct acpi_battery, min_sampling_time), 0},
 414         {offsetof(struct acpi_battery, max_averaging_interval), 0},
 415         {offsetof(struct acpi_battery, min_averaging_interval), 0},
 416         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 417         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 418         {offsetof(struct acpi_battery, model_number), 1},
 419         {offsetof(struct acpi_battery, serial_number), 1},
 420         {offsetof(struct acpi_battery, type), 1},
 421         {offsetof(struct acpi_battery, oem_info), 1},
 422 };
 423
 424 static int extract_package(struct acpi_battery *battery,
 425                            union acpi_object *package,
 426                            const struct acpi_offsets *offsets, int num)
 427 {
 428         int i;
 429         union acpi_object *element;
 430
 431         if (package->type != ACPI_TYPE_PACKAGE)
 432                 return -EFAULT;
 433         for (i = 0; i < num; ++i) {
 434                 if (package->package.count <= i)
 435                         return -EFAULT;
 436                 element = &package->package.elements[i];
 437                 if (offsets[i].mode) {
 438                         u8 *ptr = (u8 *)battery + offsets[i].offset;
 439
 440                         if (element->type == ACPI_TYPE_STRING ||
 441                             element->type == ACPI_TYPE_BUFFER)
 442                                 strncpy(ptr, element->string.pointer, 32);
 443                         else if (element->type == ACPI_TYPE_INTEGER) {
 444                                 strncpy(ptr, (u8 *)&element->integer.value,
 445                                         sizeof(u64));
 446                                 ptr[sizeof(u64)] = 0;
 447                         } else
 448                                 *ptr = 0; /* don't have value */
 449                 } else {
 450                         int *x = (int *)((u8 *)battery + offsets[i].offset);
 451                         *x = (element->type == ACPI_TYPE_INTEGER) ?
 452                                 element->integer.value : -1;
 453                 }
 454         }
 455         return 0;
 456 }
 457
 458 static int acpi_battery_get_status(struct acpi_battery *battery)
 459 {
 460         if (acpi_bus_get_status(battery->device)) {
 461                 acpi_handle_info(battery->device->handle,
 462                                  "_STA evaluation failed\n");
 463                 return -ENODEV;
 464         }
 465         return 0;
 466 }
 467
 468
 469 static int extract_battery_info(const int use_bix,
 470                          struct acpi_battery *battery,
 471                          const struct acpi_buffer *buffer)
 472 {
 473         int result = -EFAULT;
 474
 475         if (use_bix && battery_bix_broken_package)
 476                 result = extract_package(battery, buffer->pointer,
 477                                 extended_info_offsets + 1,
 478                                 ARRAY_SIZE(extended_info_offsets) - 1);
 479         else if (use_bix)
 480                 result = extract_package(battery, buffer->pointer,
 481                                 extended_info_offsets,
 482                                 ARRAY_SIZE(extended_info_offsets));
 483         else
 484                 result = extract_package(battery, buffer->pointer,
 485                                 info_offsets, ARRAY_SIZE(info_offsets));
 486         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
 487                 battery->full_charge_capacity = battery->design_capacity;
 488         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
 489             battery->power_unit && battery->design_voltage) {
 490                 battery->design_capacity = battery->design_capacity *
 491                     10000 / battery->design_voltage;
 492                 battery->full_charge_capacity = battery->full_charge_capacity *
 493                     10000 / battery->design_voltage;
 494                 battery->design_capacity_warning =
 495                     battery->design_capacity_warning *
 496                     10000 / battery->design_voltage;
 497                 /* Curiously, design_capacity_low, unlike the rest of them,
 498                  *  is correct.
 499                  */
 500                 /* capacity_granularity_* equal 1 on the systems tested, so
 501                  * it's impossible to tell if they would need an adjustment
 502                  * or not if their values were higher.
 503                  */
 504         }
 505         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
 506             battery->capacity_now > battery->full_charge_capacity)
 507                 battery->capacity_now = battery->full_charge_capacity;
 508
 509         return result;
 510 }
 511
 512 static int acpi_battery_get_info(struct acpi_battery *battery)
 513 {
 514         const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
 515         int use_bix;
 516         int result = -ENODEV;
 517
 518         if (!acpi_battery_present(battery))
 519                 return 0;
 520
 521
 522         for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
 523                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 524                 acpi_status status = AE_ERROR;
 525
 526                 mutex_lock(&battery->lock);
 527                 status = acpi_evaluate_object(battery->device->handle,
 528                                               use_bix ? "_BIX":"_BIF",
 529                                               NULL, &buffer);
 530                 mutex_unlock(&battery->lock);
 531
 532                 if (ACPI_FAILURE(status)) {
 533                         acpi_handle_info(battery->device->handle,
 534                                          "%s evaluation failed: %s\n",
 535                                          use_bix ? "_BIX":"_BIF",
 536                                          acpi_format_exception(status));
 537                 } else {
 538                         result = extract_battery_info(use_bix,
 539                                                       battery,
 540                                                       &buffer);
 541
 542                         kfree(buffer.pointer);
 543                         break;
 544                 }
 545         }
 546
 547         if (!result && !use_bix && xinfo)
 548                 pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
 549
 550         return result;
 551 }
 552
 553 static int acpi_battery_get_state(struct acpi_battery *battery)
 554 {
 555         int result = 0;
 556         acpi_status status = 0;
 557         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 558
 559         if (!acpi_battery_present(battery))
 560                 return 0;
 561
 562         if (battery->update_time &&
 563             time_before(jiffies, battery->update_time +
 564                         msecs_to_jiffies(cache_time)))
 565                 return 0;
 566
 567         mutex_lock(&battery->lock);
 568         status = acpi_evaluate_object(battery->device->handle, "_BST",
 569                                       NULL, &buffer);
 570         mutex_unlock(&battery->lock);
 571
 572         if (ACPI_FAILURE(status)) {
 573                 acpi_handle_info(battery->device->handle,
 574                                  "_BST evaluation failed: %s",
 575                                  acpi_format_exception(status));
 576                 return -ENODEV;
 577         }
 578
 579         result = extract_package(battery, buffer.pointer,
 580                                  state_offsets, ARRAY_SIZE(state_offsets));
 581         battery->update_time = jiffies;
 582         kfree(buffer.pointer);
 583
 584         /* For buggy DSDTs that report negative 16-bit values for either
 585          * charging or discharging current and/or report 0 as 65536
 586          * due to bad math.
 587          */
 588         if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
 589                 battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
 590                 (s16)(battery->rate_now) < 0) {
 591                 battery->rate_now = abs((s16)battery->rate_now);
 592                 pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
 593         }
 594
 595         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
 596             && battery->capacity_now >= 0 && battery->capacity_now <= 100)
 597                 battery->capacity_now = (battery->capacity_now *
 598                                 battery->full_charge_capacity) / 100;
 599         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
 600             battery->power_unit && battery->design_voltage) {
 601                 battery->capacity_now = battery->capacity_now *
 602                     10000 / battery->design_voltage;
 603         }
 604         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
 605             battery->capacity_now > battery->full_charge_capacity)
 606                 battery->capacity_now = battery->full_charge_capacity;
 607
 608         return result;
 609 }
 610
 611 static int acpi_battery_set_alarm(struct acpi_battery *battery)
 612 {
 613         acpi_status status = 0;
 614
 615         if (!acpi_battery_present(battery) ||
 616             !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
 617                 return -ENODEV;
 618
 619         mutex_lock(&battery->lock);
 620         status = acpi_execute_simple_method(battery->device->handle, "_BTP",
 621                                             battery->alarm);
 622         mutex_unlock(&battery->lock);
 623
 624         if (ACPI_FAILURE(status))
 625                 return -ENODEV;
 626
 627         acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
 628                           battery->alarm);
 629
 630         return 0;
 631 }
 632
 633 static int acpi_battery_init_alarm(struct acpi_battery *battery)
 634 {
 635         /* See if alarms are supported, and if so, set default */
 636         if (!acpi_has_method(battery->device->handle, "_BTP")) {
 637                 clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
 638                 return 0;
 639         }
 640         set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
 641         if (!battery->alarm)
 642                 battery->alarm = battery->design_capacity_warning;
 643         return acpi_battery_set_alarm(battery);
 644 }
 645
 646 static ssize_t acpi_battery_alarm_show(struct device *dev,
 647                                         struct device_attribute *attr,
 648                                         char *buf)
 649 {
 650         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 651
 652         return sprintf(buf, "%d\n", battery->alarm * 1000);
 653 }
 654
 655 static ssize_t acpi_battery_alarm_store(struct device *dev,
 656                                         struct device_attribute *attr,
 657                                         const char *buf, size_t count)
 658 {
 659         unsigned long x;
 660         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 661
 662         if (sscanf(buf, "%lu\n", &x) == 1)
 663                 battery->alarm = x/1000;
 664         if (acpi_battery_present(battery))
 665                 acpi_battery_set_alarm(battery);
 666         return count;
 667 }
 668
 669 static const struct device_attribute alarm_attr = {
 670         .attr = {.name = "alarm", .mode = 0644},
 671         .show = acpi_battery_alarm_show,
 672         .store = acpi_battery_alarm_store,
 673 };
 674
 675 /*
 676  * The Battery Hooking API
 677  *
 678  * This API is used inside other drivers that need to expose
 679  * platform-specific behaviour within the generic driver in a
 680  * generic way.
 681  *
 682  */
 683
 684 static LIST_HEAD(acpi_battery_list);
 685 static LIST_HEAD(battery_hook_list);
 686 static DEFINE_MUTEX(hook_mutex);
 687
 688 static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
 689 {
 690         struct acpi_battery *battery;
 691         /*
 692          * In order to remove a hook, we first need to
 693          * de-register all the batteries that are registered.
 694          */
 695         if (lock)
 696                 mutex_lock(&hook_mutex);
 697         list_for_each_entry(battery, &acpi_battery_list, list) {
 698                 hook->remove_battery(battery->bat);
 699         }
 700         list_del(&hook->list);
 701         if (lock)
 702                 mutex_unlock(&hook_mutex);
 703         pr_info("extension unregistered: %s\n", hook->name);
 704 }
 705
 706 void battery_hook_unregister(struct acpi_battery_hook *hook)
 707 {
 708         __battery_hook_unregister(hook, 1);
 709 }
 710 EXPORT_SYMBOL_GPL(battery_hook_unregister);
 711
 712 void battery_hook_register(struct acpi_battery_hook *hook)
 713 {
 714         struct acpi_battery *battery;
 715
 716         mutex_lock(&hook_mutex);
 717         INIT_LIST_HEAD(&hook->list);
 718         list_add(&hook->list, &battery_hook_list);
 719         /*
 720          * Now that the driver is registered, we need
 721          * to notify the hook that a battery is available
 722          * for each battery, so that the driver may add
 723          * its attributes.
 724          */
 725         list_for_each_entry(battery, &acpi_battery_list, list) {
 726                 if (hook->add_battery(battery->bat)) {
 727                         /*
 728                          * If a add-battery returns non-zero,
 729                          * the registration of the extension has failed,
 730                          * and we will not add it to the list of loaded
 731                          * hooks.
 732                          */
 733                         pr_err("extension failed to load: %s", hook->name);
 734                         __battery_hook_unregister(hook, 0);
 735                         goto end;
 736                 }
 737         }
 738         pr_info("new extension: %s\n", hook->name);
 739 end:
 740         mutex_unlock(&hook_mutex);
 741 }
 742 EXPORT_SYMBOL_GPL(battery_hook_register);
 743
 744 /*
 745  * This function gets called right after the battery sysfs
 746  * attributes have been added, so that the drivers that
 747  * define custom sysfs attributes can add their own.
 748  */
 749 static void battery_hook_add_battery(struct acpi_battery *battery)
 750 {
 751         struct acpi_battery_hook *hook_node, *tmp;
 752
 753         mutex_lock(&hook_mutex);
 754         INIT_LIST_HEAD(&battery->list);
 755         list_add(&battery->list, &acpi_battery_list);
 756         /*
 757          * Since we added a new battery to the list, we need to
 758          * iterate over the hooks and call add_battery for each
 759          * hook that was registered. This usually happens
 760          * when a battery gets hotplugged or initialized
 761          * during the battery module initialization.
 762          */
 763         list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
 764                 if (hook_node->add_battery(battery->bat)) {
 765                         /*
 766                          * The notification of the extensions has failed, to
 767                          * prevent further errors we will unload the extension.
 768                          */
 769                         pr_err("error in extension, unloading: %s",
 770                                         hook_node->name);
 771                         __battery_hook_unregister(hook_node, 0);
 772                 }
 773         }
 774         mutex_unlock(&hook_mutex);
 775 }
 776
 777 static void battery_hook_remove_battery(struct acpi_battery *battery)
 778 {
 779         struct acpi_battery_hook *hook;
 780
 781         mutex_lock(&hook_mutex);
 782         /*
 783          * Before removing the hook, we need to remove all
 784          * custom attributes from the battery.
 785          */
 786         list_for_each_entry(hook, &battery_hook_list, list) {
 787                 hook->remove_battery(battery->bat);
 788         }
 789         /* Then, just remove the battery from the list */
 790         list_del(&battery->list);
 791         mutex_unlock(&hook_mutex);
 792 }
 793
 794 static void __exit battery_hook_exit(void)
 795 {
 796         struct acpi_battery_hook *hook;
 797         struct acpi_battery_hook *ptr;
 798         /*
 799          * At this point, the acpi_bus_unregister_driver()
 800          * has called remove for all batteries. We just
 801          * need to remove the hooks.
 802          */
 803         list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
 804                 __battery_hook_unregister(hook, 1);
 805         }
 806         mutex_destroy(&hook_mutex);
 807 }
 808
 809 static int sysfs_add_battery(struct acpi_battery *battery)
 810 {
 811         struct power_supply_config psy_cfg = { .drv_data = battery, };
 812         bool full_cap_broken = false;
 813
 814         if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
 815             !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 816                 full_cap_broken = true;
 817
 818         if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
 819                 if (full_cap_broken) {
 820                         battery->bat_desc.properties =
 821                             charge_battery_full_cap_broken_props;
 822                         battery->bat_desc.num_properties =
 823                             ARRAY_SIZE(charge_battery_full_cap_broken_props);
 824                 } else {
 825                         battery->bat_desc.properties = charge_battery_props;
 826                         battery->bat_desc.num_properties =
 827                             ARRAY_SIZE(charge_battery_props);
 828                 }
 829         } else {
 830                 if (full_cap_broken) {
 831                         battery->bat_desc.properties =
 832                             energy_battery_full_cap_broken_props;
 833                         battery->bat_desc.num_properties =
 834                             ARRAY_SIZE(energy_battery_full_cap_broken_props);
 835                 } else {
 836                         battery->bat_desc.properties = energy_battery_props;
 837                         battery->bat_desc.num_properties =
 838                             ARRAY_SIZE(energy_battery_props);
 839                 }
 840         }
 841
 842         battery->bat_desc.name = acpi_device_bid(battery->device);
 843         battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 844         battery->bat_desc.get_property = acpi_battery_get_property;
 845
 846         battery->bat = power_supply_register_no_ws(&battery->device->dev,
 847                                 &battery->bat_desc, &psy_cfg);
 848
 849         if (IS_ERR(battery->bat)) {
 850                 int result = PTR_ERR(battery->bat);
 851
 852                 battery->bat = NULL;
 853                 return result;
 854         }
 855         battery_hook_add_battery(battery);
 856         return device_create_file(&battery->bat->dev, &alarm_attr);
 857 }
 858
 859 static void sysfs_remove_battery(struct acpi_battery *battery)
 860 {
 861         mutex_lock(&battery->sysfs_lock);
 862         if (!battery->bat) {
 863                 mutex_unlock(&battery->sysfs_lock);
 864                 return;
 865         }
 866         battery_hook_remove_battery(battery);
 867         device_remove_file(&battery->bat->dev, &alarm_attr);
 868         power_supply_unregister(battery->bat);
 869         battery->bat = NULL;
 870         mutex_unlock(&battery->sysfs_lock);
 871 }
 872
 873 static void find_battery(const struct dmi_header *dm, void *private)
 874 {
 875         struct acpi_battery *battery = (struct acpi_battery *)private;
 876         /* Note: the hardcoded offsets below have been extracted from
 877          * the source code of dmidecode.
 878          */
 879         if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
 880                 const u8 *dmi_data = (const u8 *)(dm + 1);
 881                 int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
 882
 883                 if (dm->length >= 18)
 884                         dmi_capacity *= dmi_data[17];
 885                 if (battery->design_capacity * battery->design_voltage / 1000
 886                     != dmi_capacity &&
 887                     battery->design_capacity * 10 == dmi_capacity)
 888                         set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
 889                                 &battery->flags);
 890         }
 891 }
 892
 893 /*
 894  * According to the ACPI spec, some kinds of primary batteries can
 895  * report percentage battery remaining capacity directly to OS.
 896  * In this case, it reports the Last Full Charged Capacity == 100
 897  * and BatteryPresentRate == 0xFFFFFFFF.
 898  *
 899  * Now we found some battery reports percentage remaining capacity
 900  * even if it's rechargeable.
 901  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
 902  *
 903  * Handle this correctly so that they won't break userspace.
 904  */
 905 static void acpi_battery_quirks(struct acpi_battery *battery)
 906 {
 907         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
 908                 return;
 909
 910         if (battery->full_charge_capacity == 100 &&
 911                 battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
 912                 battery->capacity_now >= 0 && battery->capacity_now <= 100) {
 913                 set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
 914                 battery->full_charge_capacity = battery->design_capacity;
 915                 battery->capacity_now = (battery->capacity_now *
 916                                 battery->full_charge_capacity) / 100;
 917         }
 918
 919         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
 920                 return;
 921
 922         if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
 923                 const char *s;
 924
 925                 s = dmi_get_system_info(DMI_PRODUCT_VERSION);
 926                 if (s && !strncasecmp(s, "ThinkPad", 8)) {
 927                         dmi_walk(find_battery, battery);
 928                         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
 929                                      &battery->flags) &&
 930                             battery->design_voltage) {
 931                                 battery->design_capacity =
 932                                     battery->design_capacity *
 933                                     10000 / battery->design_voltage;
 934                                 battery->full_charge_capacity =
 935                                     battery->full_charge_capacity *
 936                                     10000 / battery->design_voltage;
 937                                 battery->design_capacity_warning =
 938                                     battery->design_capacity_warning *
 939                                     10000 / battery->design_voltage;
 940                                 battery->capacity_now = battery->capacity_now *
 941                                     10000 / battery->design_voltage;
 942                         }
 943                 }
 944         }
 945
 946         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
 947                 return;
 948
 949         if (acpi_battery_is_degraded(battery) &&
 950             battery->capacity_now > battery->full_charge_capacity) {
 951                 set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
 952                 battery->capacity_now = battery->full_charge_capacity;
 953         }
 954 }
 955
 956 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
 957 {
 958         int result = acpi_battery_get_status(battery);
 959
 960         if (result)
 961                 return result;
 962
 963         if (!acpi_battery_present(battery)) {
 964                 sysfs_remove_battery(battery);
 965                 battery->update_time = 0;
 966                 return 0;
 967         }
 968
 969         if (resume)
 970                 return 0;
 971
 972         if (!battery->update_time) {
 973                 result = acpi_battery_get_info(battery);
 974                 if (result)
 975                         return result;
 976                 acpi_battery_init_alarm(battery);
 977         }
 978
 979         result = acpi_battery_get_state(battery);
 980         if (result)
 981                 return result;
 982         acpi_battery_quirks(battery);
 983
 984         if (!battery->bat) {
 985                 result = sysfs_add_battery(battery);
 986                 if (result)
 987                         return result;
 988         }
 989
 990         /*
 991          * Wakeup the system if battery is critical low
 992          * or lower than the alarm level
 993          */
 994         if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
 995             (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
 996              (battery->capacity_now <= battery->alarm)))
 997                 acpi_pm_wakeup_event(&battery->device->dev);
 998
 999         return result;
1000 }
1001
1002 static void acpi_battery_refresh(struct acpi_battery *battery)
1003 {
1004         int power_unit;
1005
1006         if (!battery->bat)
1007                 return;
1008
1009         power_unit = battery->power_unit;
1010
1011         acpi_battery_get_info(battery);
1012
1013         if (power_unit == battery->power_unit)
1014                 return;
1015
1016         /* The battery has changed its reporting units. */
1017         sysfs_remove_battery(battery);
1018         sysfs_add_battery(battery);
1019 }
1020
1021 /* Driver Interface */
1022 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1023 {
1024         struct acpi_battery *battery = acpi_driver_data(device);
1025         struct power_supply *old;
1026
1027         if (!battery)
1028                 return;
1029         old = battery->bat;
1030         /*
1031          * On Acer Aspire V5-573G notifications are sometimes triggered too
1032          * early. For example, when AC is unplugged and notification is
1033          * triggered, battery state is still reported as "Full", and changes to
1034          * "Discharging" only after short delay, without any notification.
1035          */
1036         if (battery_notification_delay_ms > 0)
1037                 msleep(battery_notification_delay_ms);
1038         if (event == ACPI_BATTERY_NOTIFY_INFO)
1039                 acpi_battery_refresh(battery);
1040         acpi_battery_update(battery, false);
1041         acpi_bus_generate_netlink_event(device->pnp.device_class,
1042                                         dev_name(&device->dev), event,
1043                                         acpi_battery_present(battery));
1044         acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1045         /* acpi_battery_update could remove power_supply object */
1046         if (old && battery->bat)
1047                 power_supply_changed(battery->bat);
1048 }
1049
1050 static int battery_notify(struct notifier_block *nb,
1051                                unsigned long mode, void *_unused)
1052 {
1053         struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1054                                                     pm_nb);
1055         int result;
1056
1057         switch (mode) {
1058         case PM_POST_HIBERNATION:
1059         case PM_POST_SUSPEND:
1060                 if (!acpi_battery_present(battery))
1061                         return 0;
1062
1063                 if (battery->bat) {
1064                         acpi_battery_refresh(battery);
1065                 } else {
1066                         result = acpi_battery_get_info(battery);
1067                         if (result)
1068                                 return result;
1069
1070                         result = sysfs_add_battery(battery);
1071                         if (result)
1072                                 return result;
1073                 }
1074
1075                 acpi_battery_init_alarm(battery);
1076                 acpi_battery_get_state(battery);
1077                 break;
1078         }
1079
1080         return 0;
1081 }
1082
1083 static int __init
1084 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1085 {
1086         battery_bix_broken_package = 1;
1087         return 0;
1088 }
1089
1090 static int __init
1091 battery_notification_delay_quirk(const struct dmi_system_id *d)
1092 {
1093         battery_notification_delay_ms = 1000;
1094         return 0;
1095 }
1096
1097 static int __init
1098 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1099 {
1100         battery_ac_is_broken = 1;
1101         return 0;
1102 }
1103
1104 static int __init battery_quirk_not_charging(const struct dmi_system_id *d)
1105 {
1106         battery_quirk_notcharging = 1;
1107         return 0;
1108 }
1109
1110 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1111         {
1112                 /* NEC LZ750/LS */
1113                 .callback = battery_bix_broken_package_quirk,
1114                 .matches = {
1115                         DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1116                         DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1117                 },
1118         },
1119         {
1120                 /* Acer Aspire V5-573G */
1121                 .callback = battery_notification_delay_quirk,
1122                 .matches = {
1123                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1124                         DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1125                 },
1126         },
1127         {
1128                 /* Point of View mobii wintab p800w */
1129                 .callback = battery_ac_is_broken_quirk,
1130                 .matches = {
1131                         DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1132                         DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1133                         DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1134                         /* Above matches are too generic, add bios-date match */
1135                         DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1136                 },
1137         },
1138         {
1139                 /*
1140                  * On Lenovo ThinkPads the BIOS specification defines
1141                  * a state when the bits for charging and discharging
1142                  * are both set to 0. That state is "Not Charging".
1143                  */
1144                 .callback = battery_quirk_not_charging,
1145                 .ident = "Lenovo ThinkPad",
1146                 .matches = {
1147                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
1148                         DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad"),
1149                 },
1150         },
1151         {},
1152 };
1153
1154 /*
1155  * Some machines'(E,G Lenovo Z480) ECs are not stable
1156  * during boot up and this causes battery driver fails to be
1157  * probed due to failure of getting battery information
1158  * from EC sometimes. After several retries, the operation
1159  * may work. So add retry code here and 20ms sleep between
1160  * every retries.
1161  */
1162 static int acpi_battery_update_retry(struct acpi_battery *battery)
1163 {
1164         int retry, ret;
1165
1166         for (retry = 5; retry; retry--) {
1167                 ret = acpi_battery_update(battery, false);
1168                 if (!ret)
1169                         break;
1170
1171                 msleep(20);
1172         }
1173         return ret;
1174 }
1175
1176 static int acpi_battery_add(struct acpi_device *device)
1177 {
1178         int result = 0;
1179         struct acpi_battery *battery = NULL;
1180
1181         if (!device)
1182                 return -EINVAL;
1183
1184         if (device->dep_unmet)
1185                 return -EPROBE_DEFER;
1186
1187         battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1188         if (!battery)
1189                 return -ENOMEM;
1190         battery->device = device;
1191         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1192         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1193         device->driver_data = battery;
1194         mutex_init(&battery->lock);
1195         mutex_init(&battery->sysfs_lock);
1196         if (acpi_has_method(battery->device->handle, "_BIX"))
1197                 set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1198
1199         result = acpi_battery_update_retry(battery);
1200         if (result)
1201                 goto fail;
1202
1203         pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1204                 device->status.battery_present ? "present" : "absent");
1205
1206         battery->pm_nb.notifier_call = battery_notify;
1207         register_pm_notifier(&battery->pm_nb);
1208
1209         device_init_wakeup(&device->dev, 1);
1210
1211         return result;
1212
1213 fail:
1214         sysfs_remove_battery(battery);
1215         mutex_destroy(&battery->lock);
1216         mutex_destroy(&battery->sysfs_lock);
1217         kfree(battery);
1218         return result;
1219 }
1220
1221 static int acpi_battery_remove(struct acpi_device *device)
1222 {
1223         struct acpi_battery *battery = NULL;
1224
1225         if (!device || !acpi_driver_data(device))
1226                 return -EINVAL;
1227         device_init_wakeup(&device->dev, 0);
1228         battery = acpi_driver_data(device);
1229         unregister_pm_notifier(&battery->pm_nb);
1230         sysfs_remove_battery(battery);
1231         mutex_destroy(&battery->lock);
1232         mutex_destroy(&battery->sysfs_lock);
1233         kfree(battery);
1234         return 0;
1235 }
1236
1237 #ifdef CONFIG_PM_SLEEP
1238 /* this is needed to learn about changes made in suspended state */
1239 static int acpi_battery_resume(struct device *dev)
1240 {
1241         struct acpi_battery *battery;
1242
1243         if (!dev)
1244                 return -EINVAL;
1245
1246         battery = acpi_driver_data(to_acpi_device(dev));
1247         if (!battery)
1248                 return -EINVAL;
1249
1250         battery->update_time = 0;
1251         acpi_battery_update(battery, true);
1252         return 0;
1253 }
1254 #else
1255 #define acpi_battery_resume NULL
1256 #endif
1257
1258 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1259
1260 static struct acpi_driver acpi_battery_driver = {
1261         .name = "battery",
1262         .class = ACPI_BATTERY_CLASS,
1263         .ids = battery_device_ids,
1264         .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1265         .ops = {
1266                 .add = acpi_battery_add,
1267                 .remove = acpi_battery_remove,
1268                 .notify = acpi_battery_notify,
1269                 },
1270         .drv.pm = &acpi_battery_pm,
1271 };
1272
1273 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1274 {
1275         int result;
1276
1277         if (acpi_quirk_skip_acpi_ac_and_battery())
1278                 return;
1279
1280         dmi_check_system(bat_dmi_table);
1281
1282         result = acpi_bus_register_driver(&acpi_battery_driver);
1283         battery_driver_registered = (result == 0);
1284 }
1285
1286 static int __init acpi_battery_init(void)
1287 {
1288         if (acpi_disabled)
1289                 return -ENODEV;
1290
1291         async_cookie = async_schedule(acpi_battery_init_async, NULL);
1292         return 0;
1293 }
1294
1295 static void __exit acpi_battery_exit(void)
1296 {
1297         async_synchronize_cookie(async_cookie + 1);
1298         if (battery_driver_registered) {
1299                 acpi_bus_unregister_driver(&acpi_battery_driver);
1300                 battery_hook_exit();
1301         }
1302 }
1303
1304 module_init(acpi_battery_init);
1305 module_exit(acpi_battery_exit);