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 #define MAX_STRING_LENGTH       64
  46
  47 MODULE_AUTHOR("Paul Diefenbaugh");
  48 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
  49 MODULE_DESCRIPTION("ACPI Battery Driver");
  50 MODULE_LICENSE("GPL");
  51
  52 static async_cookie_t async_cookie;
  53 static bool battery_driver_registered;
  54 static int battery_bix_broken_package;
  55 static int battery_notification_delay_ms;
  56 static int battery_ac_is_broken;
  57 static unsigned int cache_time = 1000;
  58 module_param(cache_time, uint, 0644);
  59 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  60
  61 static const struct acpi_device_id battery_device_ids[] = {
  62         {"PNP0C0A", 0},
  63
  64         /* Microsoft Surface Go 3 */
  65         {"MSHW0146", 0},
  66
  67         {"", 0},
  68 };
  69
  70 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
  71
  72 enum {
  73         ACPI_BATTERY_ALARM_PRESENT,
  74         ACPI_BATTERY_XINFO_PRESENT,
  75         ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
  76         /* On Lenovo Thinkpad models from 2010 and 2011, the power unit
  77          * switches between mWh and mAh depending on whether the system
  78          * is running on battery or not.  When mAh is the unit, most
  79          * reported values are incorrect and need to be adjusted by
  80          * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
  81          * Pre-2010 and 2012 models appear to always report in mWh and
  82          * are thus unaffected (tested with t42, t61, t500, x200, x300,
  83          * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
  84          *  the 2011 models that fixes the issue (tested on x220 with a
  85          * post-1.29 BIOS), but as of Nov. 2012, no such update is
  86          * available for the 2010 models.
  87          */
  88         ACPI_BATTERY_QUIRK_THINKPAD_MAH,
  89         /* for batteries reporting current capacity with design capacity
  90          * on a full charge, but showing degradation in full charge cap.
  91          */
  92         ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
  93 };
  94
  95 struct acpi_battery {
  96         struct mutex lock;
  97         struct mutex sysfs_lock;
  98         struct power_supply *bat;
  99         struct power_supply_desc bat_desc;
 100         struct acpi_device *device;
 101         struct notifier_block pm_nb;
 102         struct list_head list;
 103         unsigned long update_time;
 104         int revision;
 105         int rate_now;
 106         int capacity_now;
 107         int voltage_now;
 108         int design_capacity;
 109         int full_charge_capacity;
 110         int technology;
 111         int design_voltage;
 112         int design_capacity_warning;
 113         int design_capacity_low;
 114         int cycle_count;
 115         int measurement_accuracy;
 116         int max_sampling_time;
 117         int min_sampling_time;
 118         int max_averaging_interval;
 119         int min_averaging_interval;
 120         int capacity_granularity_1;
 121         int capacity_granularity_2;
 122         int alarm;
 123         char model_number[MAX_STRING_LENGTH];
 124         char serial_number[MAX_STRING_LENGTH];
 125         char type[MAX_STRING_LENGTH];
 126         char oem_info[MAX_STRING_LENGTH];
 127         int state;
 128         int power_unit;
 129         unsigned long flags;
 130 };
 131
 132 #define to_acpi_battery(x) power_supply_get_drvdata(x)
 133
 134 static inline int acpi_battery_present(struct acpi_battery *battery)
 135 {
 136         return battery->device->status.battery_present;
 137 }
 138
 139 static int acpi_battery_technology(struct acpi_battery *battery)
 140 {
 141         if (!strcasecmp("NiCd", battery->type))
 142                 return POWER_SUPPLY_TECHNOLOGY_NiCd;
 143         if (!strcasecmp("NiMH", battery->type))
 144                 return POWER_SUPPLY_TECHNOLOGY_NiMH;
 145         if (!strcasecmp("LION", battery->type))
 146                 return POWER_SUPPLY_TECHNOLOGY_LION;
 147         if (!strncasecmp("LI-ION", battery->type, 6))
 148                 return POWER_SUPPLY_TECHNOLOGY_LION;
 149         if (!strcasecmp("LiP", battery->type))
 150                 return POWER_SUPPLY_TECHNOLOGY_LIPO;
 151         return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 152 }
 153
 154 static int acpi_battery_get_state(struct acpi_battery *battery);
 155
 156 static int acpi_battery_is_charged(struct acpi_battery *battery)
 157 {
 158         /* charging, discharging or critical low */
 159         if (battery->state != 0)
 160                 return 0;
 161
 162         /* battery not reporting charge */
 163         if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
 164             battery->capacity_now == 0)
 165                 return 0;
 166
 167         /* good batteries update full_charge as the batteries degrade */
 168         if (battery->full_charge_capacity == battery->capacity_now)
 169                 return 1;
 170
 171         /* fallback to using design values for broken batteries */
 172         if (battery->design_capacity <= battery->capacity_now)
 173                 return 1;
 174
 175         /* we don't do any sort of metric based on percentages */
 176         return 0;
 177 }
 178
 179 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
 180 {
 181         return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
 182                 ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
 183                 battery->full_charge_capacity < battery->design_capacity;
 184 }
 185
 186 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
 187 {
 188         /*
 189          * Some devices wrongly report discharging if the battery's charge level
 190          * was above the device's start charging threshold atm the AC adapter
 191          * was plugged in and the device thus did not start a new charge cycle.
 192          */
 193         if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
 194             battery->rate_now == 0)
 195                 return POWER_SUPPLY_STATUS_NOT_CHARGING;
 196
 197         return POWER_SUPPLY_STATUS_DISCHARGING;
 198 }
 199
 200 static int acpi_battery_get_property(struct power_supply *psy,
 201                                      enum power_supply_property psp,
 202                                      union power_supply_propval *val)
 203 {
 204         int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
 205         struct acpi_battery *battery = to_acpi_battery(psy);
 206
 207         if (acpi_battery_present(battery)) {
 208                 /* run battery update only if it is present */
 209                 acpi_battery_get_state(battery);
 210         } else if (psp != POWER_SUPPLY_PROP_PRESENT)
 211                 return -ENODEV;
 212         switch (psp) {
 213         case POWER_SUPPLY_PROP_STATUS:
 214                 if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
 215                         val->intval = acpi_battery_handle_discharging(battery);
 216                 else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
 217                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 218                 else if (acpi_battery_is_charged(battery))
 219                         val->intval = POWER_SUPPLY_STATUS_FULL;
 220                 else
 221                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 222                 break;
 223         case POWER_SUPPLY_PROP_PRESENT:
 224                 val->intval = acpi_battery_present(battery);
 225                 break;
 226         case POWER_SUPPLY_PROP_TECHNOLOGY:
 227                 val->intval = acpi_battery_technology(battery);
 228                 break;
 229         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 230                 val->intval = battery->cycle_count;
 231                 break;
 232         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 233                 if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 234                         ret = -ENODEV;
 235                 else
 236                         val->intval = battery->design_voltage * 1000;
 237                 break;
 238         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 239                 if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
 240                         ret = -ENODEV;
 241                 else
 242                         val->intval = battery->voltage_now * 1000;
 243                 break;
 244         case POWER_SUPPLY_PROP_CURRENT_NOW:
 245         case POWER_SUPPLY_PROP_POWER_NOW:
 246                 if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
 247                         ret = -ENODEV;
 248                 else
 249                         val->intval = battery->rate_now * 1000;
 250                 break;
 251         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 252         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 253                 if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 254                         ret = -ENODEV;
 255                 else
 256                         val->intval = battery->design_capacity * 1000;
 257                 break;
 258         case POWER_SUPPLY_PROP_CHARGE_FULL:
 259         case POWER_SUPPLY_PROP_ENERGY_FULL:
 260                 if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
 261                         ret = -ENODEV;
 262                 else
 263                         val->intval = battery->full_charge_capacity * 1000;
 264                 break;
 265         case POWER_SUPPLY_PROP_CHARGE_NOW:
 266         case POWER_SUPPLY_PROP_ENERGY_NOW:
 267                 if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
 268                         ret = -ENODEV;
 269                 else
 270                         val->intval = battery->capacity_now * 1000;
 271                 break;
 272         case POWER_SUPPLY_PROP_CAPACITY:
 273                 if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
 274                         full_capacity = battery->full_charge_capacity;
 275                 else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 276                         full_capacity = battery->design_capacity;
 277
 278                 if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
 279                     full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 280                         ret = -ENODEV;
 281                 else
 282                         val->intval = battery->capacity_now * 100/
 283                                         full_capacity;
 284                 break;
 285         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 286                 if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
 287                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
 288                 else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
 289                         (battery->capacity_now <= battery->alarm))
 290                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 291                 else if (acpi_battery_is_charged(battery))
 292                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 293                 else
 294                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 295                 break;
 296         case POWER_SUPPLY_PROP_MODEL_NAME:
 297                 val->strval = battery->model_number;
 298                 break;
 299         case POWER_SUPPLY_PROP_MANUFACTURER:
 300                 val->strval = battery->oem_info;
 301                 break;
 302         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 303                 val->strval = battery->serial_number;
 304                 break;
 305         default:
 306                 ret = -EINVAL;
 307         }
 308         return ret;
 309 }
 310
 311 static enum power_supply_property charge_battery_props[] = {
 312         POWER_SUPPLY_PROP_STATUS,
 313         POWER_SUPPLY_PROP_PRESENT,
 314         POWER_SUPPLY_PROP_TECHNOLOGY,
 315         POWER_SUPPLY_PROP_CYCLE_COUNT,
 316         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 317         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 318         POWER_SUPPLY_PROP_CURRENT_NOW,
 319         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 320         POWER_SUPPLY_PROP_CHARGE_FULL,
 321         POWER_SUPPLY_PROP_CHARGE_NOW,
 322         POWER_SUPPLY_PROP_CAPACITY,
 323         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 324         POWER_SUPPLY_PROP_MODEL_NAME,
 325         POWER_SUPPLY_PROP_MANUFACTURER,
 326         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 327 };
 328
 329 static enum power_supply_property charge_battery_full_cap_broken_props[] = {
 330         POWER_SUPPLY_PROP_STATUS,
 331         POWER_SUPPLY_PROP_PRESENT,
 332         POWER_SUPPLY_PROP_TECHNOLOGY,
 333         POWER_SUPPLY_PROP_CYCLE_COUNT,
 334         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 335         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 336         POWER_SUPPLY_PROP_CURRENT_NOW,
 337         POWER_SUPPLY_PROP_CHARGE_NOW,
 338         POWER_SUPPLY_PROP_MODEL_NAME,
 339         POWER_SUPPLY_PROP_MANUFACTURER,
 340         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 341 };
 342
 343 static enum power_supply_property energy_battery_props[] = {
 344         POWER_SUPPLY_PROP_STATUS,
 345         POWER_SUPPLY_PROP_PRESENT,
 346         POWER_SUPPLY_PROP_TECHNOLOGY,
 347         POWER_SUPPLY_PROP_CYCLE_COUNT,
 348         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 349         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 350         POWER_SUPPLY_PROP_POWER_NOW,
 351         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 352         POWER_SUPPLY_PROP_ENERGY_FULL,
 353         POWER_SUPPLY_PROP_ENERGY_NOW,
 354         POWER_SUPPLY_PROP_CAPACITY,
 355         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 356         POWER_SUPPLY_PROP_MODEL_NAME,
 357         POWER_SUPPLY_PROP_MANUFACTURER,
 358         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 359 };
 360
 361 static enum power_supply_property energy_battery_full_cap_broken_props[] = {
 362         POWER_SUPPLY_PROP_STATUS,
 363         POWER_SUPPLY_PROP_PRESENT,
 364         POWER_SUPPLY_PROP_TECHNOLOGY,
 365         POWER_SUPPLY_PROP_CYCLE_COUNT,
 366         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 367         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 368         POWER_SUPPLY_PROP_POWER_NOW,
 369         POWER_SUPPLY_PROP_ENERGY_NOW,
 370         POWER_SUPPLY_PROP_MODEL_NAME,
 371         POWER_SUPPLY_PROP_MANUFACTURER,
 372         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 373 };
 374
 375 /* Battery Management */
 376 struct acpi_offsets {
 377         size_t offset;          /* offset inside struct acpi_sbs_battery */
 378         u8 mode;                /* int or string? */
 379 };
 380
 381 static const struct acpi_offsets state_offsets[] = {
 382         {offsetof(struct acpi_battery, state), 0},
 383         {offsetof(struct acpi_battery, rate_now), 0},
 384         {offsetof(struct acpi_battery, capacity_now), 0},
 385         {offsetof(struct acpi_battery, voltage_now), 0},
 386 };
 387
 388 static const struct acpi_offsets info_offsets[] = {
 389         {offsetof(struct acpi_battery, power_unit), 0},
 390         {offsetof(struct acpi_battery, design_capacity), 0},
 391         {offsetof(struct acpi_battery, full_charge_capacity), 0},
 392         {offsetof(struct acpi_battery, technology), 0},
 393         {offsetof(struct acpi_battery, design_voltage), 0},
 394         {offsetof(struct acpi_battery, design_capacity_warning), 0},
 395         {offsetof(struct acpi_battery, design_capacity_low), 0},
 396         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 397         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 398         {offsetof(struct acpi_battery, model_number), 1},
 399         {offsetof(struct acpi_battery, serial_number), 1},
 400         {offsetof(struct acpi_battery, type), 1},
 401         {offsetof(struct acpi_battery, oem_info), 1},
 402 };
 403
 404 static const struct acpi_offsets extended_info_offsets[] = {
 405         {offsetof(struct acpi_battery, revision), 0},
 406         {offsetof(struct acpi_battery, power_unit), 0},
 407         {offsetof(struct acpi_battery, design_capacity), 0},
 408         {offsetof(struct acpi_battery, full_charge_capacity), 0},
 409         {offsetof(struct acpi_battery, technology), 0},
 410         {offsetof(struct acpi_battery, design_voltage), 0},
 411         {offsetof(struct acpi_battery, design_capacity_warning), 0},
 412         {offsetof(struct acpi_battery, design_capacity_low), 0},
 413         {offsetof(struct acpi_battery, cycle_count), 0},
 414         {offsetof(struct acpi_battery, measurement_accuracy), 0},
 415         {offsetof(struct acpi_battery, max_sampling_time), 0},
 416         {offsetof(struct acpi_battery, min_sampling_time), 0},
 417         {offsetof(struct acpi_battery, max_averaging_interval), 0},
 418         {offsetof(struct acpi_battery, min_averaging_interval), 0},
 419         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 420         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 421         {offsetof(struct acpi_battery, model_number), 1},
 422         {offsetof(struct acpi_battery, serial_number), 1},
 423         {offsetof(struct acpi_battery, type), 1},
 424         {offsetof(struct acpi_battery, oem_info), 1},
 425 };
 426
 427 static int extract_package(struct acpi_battery *battery,
 428                            union acpi_object *package,
 429                            const struct acpi_offsets *offsets, int num)
 430 {
 431         int i;
 432         union acpi_object *element;
 433
 434         if (package->type != ACPI_TYPE_PACKAGE)
 435                 return -EFAULT;
 436         for (i = 0; i < num; ++i) {
 437                 if (package->package.count <= i)
 438                         return -EFAULT;
 439                 element = &package->package.elements[i];
 440                 if (offsets[i].mode) {
 441                         u8 *ptr = (u8 *)battery + offsets[i].offset;
 442                         u32 len = MAX_STRING_LENGTH;
 443
 444                         switch (element->type) {
 445                         case ACPI_TYPE_BUFFER:
 446                                 if (len > element->buffer.length + 1)
 447                                         len = element->buffer.length + 1;
 448
 449                                 fallthrough;
 450                         case ACPI_TYPE_STRING:
 451                                 strscpy(ptr, element->string.pointer, len);
 452
 453                                 break;
 454                         case ACPI_TYPE_INTEGER:
 455                                 strscpy(ptr, (u8 *)&element->integer.value, sizeof(u64) + 1);
 456
 457                                 break;
 458                         default:
 459                                 *ptr = 0; /* don't have value */
 460                         }
 461                 } else {
 462                         int *x = (int *)((u8 *)battery + offsets[i].offset);
 463                         *x = (element->type == ACPI_TYPE_INTEGER) ?
 464                                 element->integer.value : -1;
 465                 }
 466         }
 467         return 0;
 468 }
 469
 470 static int acpi_battery_get_status(struct acpi_battery *battery)
 471 {
 472         if (acpi_bus_get_status(battery->device)) {
 473                 acpi_handle_info(battery->device->handle,
 474                                  "_STA evaluation failed\n");
 475                 return -ENODEV;
 476         }
 477         return 0;
 478 }
 479
 480
 481 static int extract_battery_info(const int use_bix,
 482                          struct acpi_battery *battery,
 483                          const struct acpi_buffer *buffer)
 484 {
 485         int result = -EFAULT;
 486
 487         if (use_bix && battery_bix_broken_package)
 488                 result = extract_package(battery, buffer->pointer,
 489                                 extended_info_offsets + 1,
 490                                 ARRAY_SIZE(extended_info_offsets) - 1);
 491         else if (use_bix)
 492                 result = extract_package(battery, buffer->pointer,
 493                                 extended_info_offsets,
 494                                 ARRAY_SIZE(extended_info_offsets));
 495         else
 496                 result = extract_package(battery, buffer->pointer,
 497                                 info_offsets, ARRAY_SIZE(info_offsets));
 498         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
 499                 battery->full_charge_capacity = battery->design_capacity;
 500         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
 501             battery->power_unit && battery->design_voltage) {
 502                 battery->design_capacity = battery->design_capacity *
 503                     10000 / battery->design_voltage;
 504                 battery->full_charge_capacity = battery->full_charge_capacity *
 505                     10000 / battery->design_voltage;
 506                 battery->design_capacity_warning =
 507                     battery->design_capacity_warning *
 508                     10000 / battery->design_voltage;
 509                 /* Curiously, design_capacity_low, unlike the rest of them,
 510                  *  is correct.
 511                  */
 512                 /* capacity_granularity_* equal 1 on the systems tested, so
 513                  * it's impossible to tell if they would need an adjustment
 514                  * or not if their values were higher.
 515                  */
 516         }
 517         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
 518             battery->capacity_now > battery->full_charge_capacity)
 519                 battery->capacity_now = battery->full_charge_capacity;
 520
 521         return result;
 522 }
 523
 524 static int acpi_battery_get_info(struct acpi_battery *battery)
 525 {
 526         const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
 527         int use_bix;
 528         int result = -ENODEV;
 529
 530         if (!acpi_battery_present(battery))
 531                 return 0;
 532
 533
 534         for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
 535                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 536                 acpi_status status = AE_ERROR;
 537
 538                 mutex_lock(&battery->lock);
 539                 status = acpi_evaluate_object(battery->device->handle,
 540                                               use_bix ? "_BIX":"_BIF",
 541                                               NULL, &buffer);
 542                 mutex_unlock(&battery->lock);
 543
 544                 if (ACPI_FAILURE(status)) {
 545                         acpi_handle_info(battery->device->handle,
 546                                          "%s evaluation failed: %s\n",
 547                                          use_bix ? "_BIX":"_BIF",
 548                                          acpi_format_exception(status));
 549                 } else {
 550                         result = extract_battery_info(use_bix,
 551                                                       battery,
 552                                                       &buffer);
 553
 554                         kfree(buffer.pointer);
 555                         break;
 556                 }
 557         }
 558
 559         if (!result && !use_bix && xinfo)
 560                 pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
 561
 562         return result;
 563 }
 564
 565 static int acpi_battery_get_state(struct acpi_battery *battery)
 566 {
 567         int result = 0;
 568         acpi_status status = 0;
 569         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 570
 571         if (!acpi_battery_present(battery))
 572                 return 0;
 573
 574         if (battery->update_time &&
 575             time_before(jiffies, battery->update_time +
 576                         msecs_to_jiffies(cache_time)))
 577                 return 0;
 578
 579         mutex_lock(&battery->lock);
 580         status = acpi_evaluate_object(battery->device->handle, "_BST",
 581                                       NULL, &buffer);
 582         mutex_unlock(&battery->lock);
 583
 584         if (ACPI_FAILURE(status)) {
 585                 acpi_handle_info(battery->device->handle,
 586                                  "_BST evaluation failed: %s",
 587                                  acpi_format_exception(status));
 588                 return -ENODEV;
 589         }
 590
 591         result = extract_package(battery, buffer.pointer,
 592                                  state_offsets, ARRAY_SIZE(state_offsets));
 593         battery->update_time = jiffies;
 594         kfree(buffer.pointer);
 595
 596         /* For buggy DSDTs that report negative 16-bit values for either
 597          * charging or discharging current and/or report 0 as 65536
 598          * due to bad math.
 599          */
 600         if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
 601                 battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
 602                 (s16)(battery->rate_now) < 0) {
 603                 battery->rate_now = abs((s16)battery->rate_now);
 604                 pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
 605         }
 606
 607         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
 608             && battery->capacity_now >= 0 && battery->capacity_now <= 100)
 609                 battery->capacity_now = (battery->capacity_now *
 610                                 battery->full_charge_capacity) / 100;
 611         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
 612             battery->power_unit && battery->design_voltage) {
 613                 battery->capacity_now = battery->capacity_now *
 614                     10000 / battery->design_voltage;
 615         }
 616         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
 617             battery->capacity_now > battery->full_charge_capacity)
 618                 battery->capacity_now = battery->full_charge_capacity;
 619
 620         return result;
 621 }
 622
 623 static int acpi_battery_set_alarm(struct acpi_battery *battery)
 624 {
 625         acpi_status status = 0;
 626
 627         if (!acpi_battery_present(battery) ||
 628             !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
 629                 return -ENODEV;
 630
 631         mutex_lock(&battery->lock);
 632         status = acpi_execute_simple_method(battery->device->handle, "_BTP",
 633                                             battery->alarm);
 634         mutex_unlock(&battery->lock);
 635
 636         if (ACPI_FAILURE(status))
 637                 return -ENODEV;
 638
 639         acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
 640                           battery->alarm);
 641
 642         return 0;
 643 }
 644
 645 static int acpi_battery_init_alarm(struct acpi_battery *battery)
 646 {
 647         /* See if alarms are supported, and if so, set default */
 648         if (!acpi_has_method(battery->device->handle, "_BTP")) {
 649                 clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
 650                 return 0;
 651         }
 652         set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
 653         if (!battery->alarm)
 654                 battery->alarm = battery->design_capacity_warning;
 655         return acpi_battery_set_alarm(battery);
 656 }
 657
 658 static ssize_t acpi_battery_alarm_show(struct device *dev,
 659                                         struct device_attribute *attr,
 660                                         char *buf)
 661 {
 662         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 663
 664         return sprintf(buf, "%d\n", battery->alarm * 1000);
 665 }
 666
 667 static ssize_t acpi_battery_alarm_store(struct device *dev,
 668                                         struct device_attribute *attr,
 669                                         const char *buf, size_t count)
 670 {
 671         unsigned long x;
 672         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 673
 674         if (sscanf(buf, "%lu\n", &x) == 1)
 675                 battery->alarm = x/1000;
 676         if (acpi_battery_present(battery))
 677                 acpi_battery_set_alarm(battery);
 678         return count;
 679 }
 680
 681 static const struct device_attribute alarm_attr = {
 682         .attr = {.name = "alarm", .mode = 0644},
 683         .show = acpi_battery_alarm_show,
 684         .store = acpi_battery_alarm_store,
 685 };
 686
 687 /*
 688  * The Battery Hooking API
 689  *
 690  * This API is used inside other drivers that need to expose
 691  * platform-specific behaviour within the generic driver in a
 692  * generic way.
 693  *
 694  */
 695
 696 static LIST_HEAD(acpi_battery_list);
 697 static LIST_HEAD(battery_hook_list);
 698 static DEFINE_MUTEX(hook_mutex);
 699
 700 static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
 701 {
 702         struct acpi_battery *battery;
 703         /*
 704          * In order to remove a hook, we first need to
 705          * de-register all the batteries that are registered.
 706          */
 707         if (lock)
 708                 mutex_lock(&hook_mutex);
 709         list_for_each_entry(battery, &acpi_battery_list, list) {
 710                 if (!hook->remove_battery(battery->bat, hook))
 711                         power_supply_changed(battery->bat);
 712         }
 713         list_del(&hook->list);
 714         if (lock)
 715                 mutex_unlock(&hook_mutex);
 716         pr_info("extension unregistered: %s\n", hook->name);
 717 }
 718
 719 void battery_hook_unregister(struct acpi_battery_hook *hook)
 720 {
 721         __battery_hook_unregister(hook, 1);
 722 }
 723 EXPORT_SYMBOL_GPL(battery_hook_unregister);
 724
 725 void battery_hook_register(struct acpi_battery_hook *hook)
 726 {
 727         struct acpi_battery *battery;
 728
 729         mutex_lock(&hook_mutex);
 730         INIT_LIST_HEAD(&hook->list);
 731         list_add(&hook->list, &battery_hook_list);
 732         /*
 733          * Now that the driver is registered, we need
 734          * to notify the hook that a battery is available
 735          * for each battery, so that the driver may add
 736          * its attributes.
 737          */
 738         list_for_each_entry(battery, &acpi_battery_list, list) {
 739                 if (hook->add_battery(battery->bat, hook)) {
 740                         /*
 741                          * If a add-battery returns non-zero,
 742                          * the registration of the extension has failed,
 743                          * and we will not add it to the list of loaded
 744                          * hooks.
 745                          */
 746                         pr_err("extension failed to load: %s", hook->name);
 747                         __battery_hook_unregister(hook, 0);
 748                         goto end;
 749                 }
 750
 751                 power_supply_changed(battery->bat);
 752         }
 753         pr_info("new extension: %s\n", hook->name);
 754 end:
 755         mutex_unlock(&hook_mutex);
 756 }
 757 EXPORT_SYMBOL_GPL(battery_hook_register);
 758
 759 /*
 760  * This function gets called right after the battery sysfs
 761  * attributes have been added, so that the drivers that
 762  * define custom sysfs attributes can add their own.
 763  */
 764 static void battery_hook_add_battery(struct acpi_battery *battery)
 765 {
 766         struct acpi_battery_hook *hook_node, *tmp;
 767
 768         mutex_lock(&hook_mutex);
 769         INIT_LIST_HEAD(&battery->list);
 770         list_add(&battery->list, &acpi_battery_list);
 771         /*
 772          * Since we added a new battery to the list, we need to
 773          * iterate over the hooks and call add_battery for each
 774          * hook that was registered. This usually happens
 775          * when a battery gets hotplugged or initialized
 776          * during the battery module initialization.
 777          */
 778         list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
 779                 if (hook_node->add_battery(battery->bat, hook_node)) {
 780                         /*
 781                          * The notification of the extensions has failed, to
 782                          * prevent further errors we will unload the extension.
 783                          */
 784                         pr_err("error in extension, unloading: %s",
 785                                         hook_node->name);
 786                         __battery_hook_unregister(hook_node, 0);
 787                 }
 788         }
 789         mutex_unlock(&hook_mutex);
 790 }
 791
 792 static void battery_hook_remove_battery(struct acpi_battery *battery)
 793 {
 794         struct acpi_battery_hook *hook;
 795
 796         mutex_lock(&hook_mutex);
 797         /*
 798          * Before removing the hook, we need to remove all
 799          * custom attributes from the battery.
 800          */
 801         list_for_each_entry(hook, &battery_hook_list, list) {
 802                 hook->remove_battery(battery->bat, hook);
 803         }
 804         /* Then, just remove the battery from the list */
 805         list_del(&battery->list);
 806         mutex_unlock(&hook_mutex);
 807 }
 808
 809 static void __exit battery_hook_exit(void)
 810 {
 811         struct acpi_battery_hook *hook;
 812         struct acpi_battery_hook *ptr;
 813         /*
 814          * At this point, the acpi_bus_unregister_driver()
 815          * has called remove for all batteries. We just
 816          * need to remove the hooks.
 817          */
 818         list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
 819                 __battery_hook_unregister(hook, 1);
 820         }
 821         mutex_destroy(&hook_mutex);
 822 }
 823
 824 static int sysfs_add_battery(struct acpi_battery *battery)
 825 {
 826         struct power_supply_config psy_cfg = { .drv_data = battery, };
 827         bool full_cap_broken = false;
 828
 829         if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
 830             !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
 831                 full_cap_broken = true;
 832
 833         if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
 834                 if (full_cap_broken) {
 835                         battery->bat_desc.properties =
 836                             charge_battery_full_cap_broken_props;
 837                         battery->bat_desc.num_properties =
 838                             ARRAY_SIZE(charge_battery_full_cap_broken_props);
 839                 } else {
 840                         battery->bat_desc.properties = charge_battery_props;
 841                         battery->bat_desc.num_properties =
 842                             ARRAY_SIZE(charge_battery_props);
 843                 }
 844         } else {
 845                 if (full_cap_broken) {
 846                         battery->bat_desc.properties =
 847                             energy_battery_full_cap_broken_props;
 848                         battery->bat_desc.num_properties =
 849                             ARRAY_SIZE(energy_battery_full_cap_broken_props);
 850                 } else {
 851                         battery->bat_desc.properties = energy_battery_props;
 852                         battery->bat_desc.num_properties =
 853                             ARRAY_SIZE(energy_battery_props);
 854                 }
 855         }
 856
 857         battery->bat_desc.name = acpi_device_bid(battery->device);
 858         battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 859         battery->bat_desc.get_property = acpi_battery_get_property;
 860
 861         battery->bat = power_supply_register_no_ws(&battery->device->dev,
 862                                 &battery->bat_desc, &psy_cfg);
 863
 864         if (IS_ERR(battery->bat)) {
 865                 int result = PTR_ERR(battery->bat);
 866
 867                 battery->bat = NULL;
 868                 return result;
 869         }
 870         battery_hook_add_battery(battery);
 871         return device_create_file(&battery->bat->dev, &alarm_attr);
 872 }
 873
 874 static void sysfs_remove_battery(struct acpi_battery *battery)
 875 {
 876         mutex_lock(&battery->sysfs_lock);
 877         if (!battery->bat) {
 878                 mutex_unlock(&battery->sysfs_lock);
 879                 return;
 880         }
 881         battery_hook_remove_battery(battery);
 882         device_remove_file(&battery->bat->dev, &alarm_attr);
 883         power_supply_unregister(battery->bat);
 884         battery->bat = NULL;
 885         mutex_unlock(&battery->sysfs_lock);
 886 }
 887
 888 static void find_battery(const struct dmi_header *dm, void *private)
 889 {
 890         struct acpi_battery *battery = (struct acpi_battery *)private;
 891         /* Note: the hardcoded offsets below have been extracted from
 892          * the source code of dmidecode.
 893          */
 894         if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
 895                 const u8 *dmi_data = (const u8 *)(dm + 1);
 896                 int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
 897
 898                 if (dm->length >= 18)
 899                         dmi_capacity *= dmi_data[17];
 900                 if (battery->design_capacity * battery->design_voltage / 1000
 901                     != dmi_capacity &&
 902                     battery->design_capacity * 10 == dmi_capacity)
 903                         set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
 904                                 &battery->flags);
 905         }
 906 }
 907
 908 /*
 909  * According to the ACPI spec, some kinds of primary batteries can
 910  * report percentage battery remaining capacity directly to OS.
 911  * In this case, it reports the Last Full Charged Capacity == 100
 912  * and BatteryPresentRate == 0xFFFFFFFF.
 913  *
 914  * Now we found some battery reports percentage remaining capacity
 915  * even if it's rechargeable.
 916  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
 917  *
 918  * Handle this correctly so that they won't break userspace.
 919  */
 920 static void acpi_battery_quirks(struct acpi_battery *battery)
 921 {
 922         if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
 923                 return;
 924
 925         if (battery->full_charge_capacity == 100 &&
 926                 battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
 927                 battery->capacity_now >= 0 && battery->capacity_now <= 100) {
 928                 set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
 929                 battery->full_charge_capacity = battery->design_capacity;
 930                 battery->capacity_now = (battery->capacity_now *
 931                                 battery->full_charge_capacity) / 100;
 932         }
 933
 934         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
 935                 return;
 936
 937         if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
 938                 const char *s;
 939
 940                 s = dmi_get_system_info(DMI_PRODUCT_VERSION);
 941                 if (s && !strncasecmp(s, "ThinkPad", 8)) {
 942                         dmi_walk(find_battery, battery);
 943                         if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
 944                                      &battery->flags) &&
 945                             battery->design_voltage) {
 946                                 battery->design_capacity =
 947                                     battery->design_capacity *
 948                                     10000 / battery->design_voltage;
 949                                 battery->full_charge_capacity =
 950                                     battery->full_charge_capacity *
 951                                     10000 / battery->design_voltage;
 952                                 battery->design_capacity_warning =
 953                                     battery->design_capacity_warning *
 954                                     10000 / battery->design_voltage;
 955                                 battery->capacity_now = battery->capacity_now *
 956                                     10000 / battery->design_voltage;
 957                         }
 958                 }
 959         }
 960
 961         if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
 962                 return;
 963
 964         if (acpi_battery_is_degraded(battery) &&
 965             battery->capacity_now > battery->full_charge_capacity) {
 966                 set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
 967                 battery->capacity_now = battery->full_charge_capacity;
 968         }
 969 }
 970
 971 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
 972 {
 973         int result = acpi_battery_get_status(battery);
 974
 975         if (result)
 976                 return result;
 977
 978         if (!acpi_battery_present(battery)) {
 979                 sysfs_remove_battery(battery);
 980                 battery->update_time = 0;
 981                 return 0;
 982         }
 983
 984         if (resume)
 985                 return 0;
 986
 987         if (!battery->update_time) {
 988                 result = acpi_battery_get_info(battery);
 989                 if (result)
 990                         return result;
 991                 acpi_battery_init_alarm(battery);
 992         }
 993
 994         result = acpi_battery_get_state(battery);
 995         if (result)
 996                 return result;
 997         acpi_battery_quirks(battery);
 998
 999         if (!battery->bat) {
1000                 result = sysfs_add_battery(battery);
1001                 if (result)
1002                         return result;
1003         }
1004
1005         /*
1006          * Wakeup the system if battery is critical low
1007          * or lower than the alarm level
1008          */
1009         if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1010             (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1011              (battery->capacity_now <= battery->alarm)))
1012                 acpi_pm_wakeup_event(&battery->device->dev);
1013
1014         return result;
1015 }
1016
1017 static void acpi_battery_refresh(struct acpi_battery *battery)
1018 {
1019         int power_unit;
1020
1021         if (!battery->bat)
1022                 return;
1023
1024         power_unit = battery->power_unit;
1025
1026         acpi_battery_get_info(battery);
1027
1028         if (power_unit == battery->power_unit)
1029                 return;
1030
1031         /* The battery has changed its reporting units. */
1032         sysfs_remove_battery(battery);
1033         sysfs_add_battery(battery);
1034 }
1035
1036 /* Driver Interface */
1037 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1038 {
1039         struct acpi_battery *battery = acpi_driver_data(device);
1040         struct power_supply *old;
1041
1042         if (!battery)
1043                 return;
1044         old = battery->bat;
1045         /*
1046          * On Acer Aspire V5-573G notifications are sometimes triggered too
1047          * early. For example, when AC is unplugged and notification is
1048          * triggered, battery state is still reported as "Full", and changes to
1049          * "Discharging" only after short delay, without any notification.
1050          */
1051         if (battery_notification_delay_ms > 0)
1052                 msleep(battery_notification_delay_ms);
1053         if (event == ACPI_BATTERY_NOTIFY_INFO)
1054                 acpi_battery_refresh(battery);
1055         acpi_battery_update(battery, false);
1056         acpi_bus_generate_netlink_event(device->pnp.device_class,
1057                                         dev_name(&device->dev), event,
1058                                         acpi_battery_present(battery));
1059         acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1060         /* acpi_battery_update could remove power_supply object */
1061         if (old && battery->bat)
1062                 power_supply_changed(battery->bat);
1063 }
1064
1065 static int battery_notify(struct notifier_block *nb,
1066                                unsigned long mode, void *_unused)
1067 {
1068         struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1069                                                     pm_nb);
1070         int result;
1071
1072         switch (mode) {
1073         case PM_POST_HIBERNATION:
1074         case PM_POST_SUSPEND:
1075                 if (!acpi_battery_present(battery))
1076                         return 0;
1077
1078                 if (battery->bat) {
1079                         acpi_battery_refresh(battery);
1080                 } else {
1081                         result = acpi_battery_get_info(battery);
1082                         if (result)
1083                                 return result;
1084
1085                         result = sysfs_add_battery(battery);
1086                         if (result)
1087                                 return result;
1088                 }
1089
1090                 acpi_battery_init_alarm(battery);
1091                 acpi_battery_get_state(battery);
1092                 break;
1093         }
1094
1095         return 0;
1096 }
1097
1098 static int __init
1099 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1100 {
1101         battery_bix_broken_package = 1;
1102         return 0;
1103 }
1104
1105 static int __init
1106 battery_notification_delay_quirk(const struct dmi_system_id *d)
1107 {
1108         battery_notification_delay_ms = 1000;
1109         return 0;
1110 }
1111
1112 static int __init
1113 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1114 {
1115         battery_ac_is_broken = 1;
1116         return 0;
1117 }
1118
1119 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1120         {
1121                 /* NEC LZ750/LS */
1122                 .callback = battery_bix_broken_package_quirk,
1123                 .matches = {
1124                         DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1125                         DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1126                 },
1127         },
1128         {
1129                 /* Acer Aspire V5-573G */
1130                 .callback = battery_notification_delay_quirk,
1131                 .matches = {
1132                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1133                         DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1134                 },
1135         },
1136         {
1137                 /* Point of View mobii wintab p800w */
1138                 .callback = battery_ac_is_broken_quirk,
1139                 .matches = {
1140                         DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1141                         DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1142                         DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1143                         /* Above matches are too generic, add bios-date match */
1144                         DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1145                 },
1146         },
1147         {
1148                 /* Microsoft Surface Go 3 */
1149                 .callback = battery_notification_delay_quirk,
1150                 .matches = {
1151                         DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1152                         DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1153                 },
1154         },
1155         {},
1156 };
1157
1158 /*
1159  * Some machines'(E,G Lenovo Z480) ECs are not stable
1160  * during boot up and this causes battery driver fails to be
1161  * probed due to failure of getting battery information
1162  * from EC sometimes. After several retries, the operation
1163  * may work. So add retry code here and 20ms sleep between
1164  * every retries.
1165  */
1166 static int acpi_battery_update_retry(struct acpi_battery *battery)
1167 {
1168         int retry, ret;
1169
1170         for (retry = 5; retry; retry--) {
1171                 ret = acpi_battery_update(battery, false);
1172                 if (!ret)
1173                         break;
1174
1175                 msleep(20);
1176         }
1177         return ret;
1178 }
1179
1180 static int acpi_battery_add(struct acpi_device *device)
1181 {
1182         int result = 0;
1183         struct acpi_battery *battery = NULL;
1184
1185         if (!device)
1186                 return -EINVAL;
1187
1188         if (device->dep_unmet)
1189                 return -EPROBE_DEFER;
1190
1191         battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1192         if (!battery)
1193                 return -ENOMEM;
1194         battery->device = device;
1195         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1196         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1197         device->driver_data = battery;
1198         mutex_init(&battery->lock);
1199         mutex_init(&battery->sysfs_lock);
1200         if (acpi_has_method(battery->device->handle, "_BIX"))
1201                 set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1202
1203         result = acpi_battery_update_retry(battery);
1204         if (result)
1205                 goto fail;
1206
1207         pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1208                 device->status.battery_present ? "present" : "absent");
1209
1210         battery->pm_nb.notifier_call = battery_notify;
1211         register_pm_notifier(&battery->pm_nb);
1212
1213         device_init_wakeup(&device->dev, 1);
1214
1215         return result;
1216
1217 fail:
1218         sysfs_remove_battery(battery);
1219         mutex_destroy(&battery->lock);
1220         mutex_destroy(&battery->sysfs_lock);
1221         kfree(battery);
1222         return result;
1223 }
1224
1225 static void acpi_battery_remove(struct acpi_device *device)
1226 {
1227         struct acpi_battery *battery = NULL;
1228
1229         if (!device || !acpi_driver_data(device))
1230                 return;
1231         device_init_wakeup(&device->dev, 0);
1232         battery = acpi_driver_data(device);
1233         unregister_pm_notifier(&battery->pm_nb);
1234         sysfs_remove_battery(battery);
1235         mutex_destroy(&battery->lock);
1236         mutex_destroy(&battery->sysfs_lock);
1237         kfree(battery);
1238 }
1239
1240 #ifdef CONFIG_PM_SLEEP
1241 /* this is needed to learn about changes made in suspended state */
1242 static int acpi_battery_resume(struct device *dev)
1243 {
1244         struct acpi_battery *battery;
1245
1246         if (!dev)
1247                 return -EINVAL;
1248
1249         battery = acpi_driver_data(to_acpi_device(dev));
1250         if (!battery)
1251                 return -EINVAL;
1252
1253         battery->update_time = 0;
1254         acpi_battery_update(battery, true);
1255         return 0;
1256 }
1257 #else
1258 #define acpi_battery_resume NULL
1259 #endif
1260
1261 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1262
1263 static struct acpi_driver acpi_battery_driver = {
1264         .name = "battery",
1265         .class = ACPI_BATTERY_CLASS,
1266         .ids = battery_device_ids,
1267         .flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1268         .ops = {
1269                 .add = acpi_battery_add,
1270                 .remove = acpi_battery_remove,
1271                 .notify = acpi_battery_notify,
1272                 },
1273         .drv.pm = &acpi_battery_pm,
1274 };
1275
1276 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1277 {
1278         int result;
1279
1280         if (acpi_quirk_skip_acpi_ac_and_battery())
1281                 return;
1282
1283         dmi_check_system(bat_dmi_table);
1284
1285         result = acpi_bus_register_driver(&acpi_battery_driver);
1286         battery_driver_registered = (result == 0);
1287 }
1288
1289 static int __init acpi_battery_init(void)
1290 {
1291         if (acpi_disabled)
1292                 return -ENODEV;
1293
1294         async_cookie = async_schedule(acpi_battery_init_async, NULL);
1295         return 0;
1296 }
1297
1298 static void __exit acpi_battery_exit(void)
1299 {
1300         async_synchronize_cookie(async_cookie + 1);
1301         if (battery_driver_registered) {
1302                 acpi_bus_unregister_driver(&acpi_battery_driver);
1303                 battery_hook_exit();
1304         }
1305 }
1306
1307 module_init(acpi_battery_init);
1308 module_exit(acpi_battery_exit);