linux/drivers/acpi/battery.c
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   1/*
   2 *  battery.c - ACPI Battery Driver (Revision: 2.0)
   3 *
   4 *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
   5 *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
   6 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   7 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   8 *
   9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  10 *
  11 *  This program is free software; you can redistribute it and/or modify
  12 *  it under the terms of the GNU General Public License as published by
  13 *  the Free Software Foundation; either version 2 of the License, or (at
  14 *  your option) any later version.
  15 *
  16 *  This program is distributed in the hope that it will be useful, but
  17 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  18 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 *  General Public License for more details.
  20 *
  21 *  You should have received a copy of the GNU General Public License along
  22 *  with this program; if not, write to the Free Software Foundation, Inc.,
  23 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  24 *
  25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26 */
  27
  28#include <linux/kernel.h>
  29#include <linux/module.h>
  30#include <linux/init.h>
  31#include <linux/types.h>
  32#include <linux/jiffies.h>
  33
  34#ifdef CONFIG_ACPI_PROCFS_POWER
  35#include <linux/proc_fs.h>
  36#include <linux/seq_file.h>
  37#include <asm/uaccess.h>
  38#endif
  39
  40#include <acpi/acpi_bus.h>
  41#include <acpi/acpi_drivers.h>
  42
  43#ifdef CONFIG_ACPI_SYSFS_POWER
  44#include <linux/power_supply.h>
  45#endif
  46
  47#define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
  48
  49#define ACPI_BATTERY_COMPONENT          0x00040000
  50#define ACPI_BATTERY_CLASS              "battery"
  51#define ACPI_BATTERY_DEVICE_NAME        "Battery"
  52#define ACPI_BATTERY_NOTIFY_STATUS      0x80
  53#define ACPI_BATTERY_NOTIFY_INFO        0x81
  54
  55#define _COMPONENT              ACPI_BATTERY_COMPONENT
  56
  57ACPI_MODULE_NAME("battery");
  58
  59MODULE_AUTHOR("Paul Diefenbaugh");
  60MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
  61MODULE_DESCRIPTION("ACPI Battery Driver");
  62MODULE_LICENSE("GPL");
  63
  64static unsigned int cache_time = 1000;
  65module_param(cache_time, uint, 0644);
  66MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  67
  68#ifdef CONFIG_ACPI_PROCFS_POWER
  69extern struct proc_dir_entry *acpi_lock_battery_dir(void);
  70extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
  71
  72enum acpi_battery_files {
  73        info_tag = 0,
  74        state_tag,
  75        alarm_tag,
  76        ACPI_BATTERY_NUMFILES,
  77};
  78
  79#endif
  80
  81static const struct acpi_device_id battery_device_ids[] = {
  82        {"PNP0C0A", 0},
  83        {"", 0},
  84};
  85
  86MODULE_DEVICE_TABLE(acpi, battery_device_ids);
  87
  88
  89struct acpi_battery {
  90        struct mutex lock;
  91#ifdef CONFIG_ACPI_SYSFS_POWER
  92        struct power_supply bat;
  93#endif
  94        struct acpi_device *device;
  95        unsigned long update_time;
  96        int current_now;
  97        int capacity_now;
  98        int voltage_now;
  99        int design_capacity;
 100        int full_charge_capacity;
 101        int technology;
 102        int design_voltage;
 103        int design_capacity_warning;
 104        int design_capacity_low;
 105        int capacity_granularity_1;
 106        int capacity_granularity_2;
 107        int alarm;
 108        char model_number[32];
 109        char serial_number[32];
 110        char type[32];
 111        char oem_info[32];
 112        int state;
 113        int power_unit;
 114        u8 alarm_present;
 115};
 116
 117#define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
 118
 119inline int acpi_battery_present(struct acpi_battery *battery)
 120{
 121        return battery->device->status.battery_present;
 122}
 123
 124#ifdef CONFIG_ACPI_SYSFS_POWER
 125static int acpi_battery_technology(struct acpi_battery *battery)
 126{
 127        if (!strcasecmp("NiCd", battery->type))
 128                return POWER_SUPPLY_TECHNOLOGY_NiCd;
 129        if (!strcasecmp("NiMH", battery->type))
 130                return POWER_SUPPLY_TECHNOLOGY_NiMH;
 131        if (!strcasecmp("LION", battery->type))
 132                return POWER_SUPPLY_TECHNOLOGY_LION;
 133        if (!strncasecmp("LI-ION", battery->type, 6))
 134                return POWER_SUPPLY_TECHNOLOGY_LION;
 135        if (!strcasecmp("LiP", battery->type))
 136                return POWER_SUPPLY_TECHNOLOGY_LIPO;
 137        return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 138}
 139
 140static int acpi_battery_get_state(struct acpi_battery *battery);
 141
 142static int acpi_battery_get_property(struct power_supply *psy,
 143                                     enum power_supply_property psp,
 144                                     union power_supply_propval *val)
 145{
 146        struct acpi_battery *battery = to_acpi_battery(psy);
 147
 148        if (acpi_battery_present(battery)) {
 149                /* run battery update only if it is present */
 150                acpi_battery_get_state(battery);
 151        } else if (psp != POWER_SUPPLY_PROP_PRESENT)
 152                return -ENODEV;
 153        switch (psp) {
 154        case POWER_SUPPLY_PROP_STATUS:
 155                if (battery->state & 0x01)
 156                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 157                else if (battery->state & 0x02)
 158                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
 159                else if (battery->state == 0)
 160                        val->intval = POWER_SUPPLY_STATUS_FULL;
 161                else
 162                        val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 163                break;
 164        case POWER_SUPPLY_PROP_PRESENT:
 165                val->intval = acpi_battery_present(battery);
 166                break;
 167        case POWER_SUPPLY_PROP_TECHNOLOGY:
 168                val->intval = acpi_battery_technology(battery);
 169                break;
 170        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 171                val->intval = battery->design_voltage * 1000;
 172                break;
 173        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 174                val->intval = battery->voltage_now * 1000;
 175                break;
 176        case POWER_SUPPLY_PROP_CURRENT_NOW:
 177                val->intval = battery->current_now * 1000;
 178                break;
 179        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 180        case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 181                val->intval = battery->design_capacity * 1000;
 182                break;
 183        case POWER_SUPPLY_PROP_CHARGE_FULL:
 184        case POWER_SUPPLY_PROP_ENERGY_FULL:
 185                val->intval = battery->full_charge_capacity * 1000;
 186                break;
 187        case POWER_SUPPLY_PROP_CHARGE_NOW:
 188        case POWER_SUPPLY_PROP_ENERGY_NOW:
 189                val->intval = battery->capacity_now * 1000;
 190                break;
 191        case POWER_SUPPLY_PROP_MODEL_NAME:
 192                val->strval = battery->model_number;
 193                break;
 194        case POWER_SUPPLY_PROP_MANUFACTURER:
 195                val->strval = battery->oem_info;
 196                break;
 197        default:
 198                return -EINVAL;
 199        }
 200        return 0;
 201}
 202
 203static enum power_supply_property charge_battery_props[] = {
 204        POWER_SUPPLY_PROP_STATUS,
 205        POWER_SUPPLY_PROP_PRESENT,
 206        POWER_SUPPLY_PROP_TECHNOLOGY,
 207        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 208        POWER_SUPPLY_PROP_VOLTAGE_NOW,
 209        POWER_SUPPLY_PROP_CURRENT_NOW,
 210        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 211        POWER_SUPPLY_PROP_CHARGE_FULL,
 212        POWER_SUPPLY_PROP_CHARGE_NOW,
 213        POWER_SUPPLY_PROP_MODEL_NAME,
 214        POWER_SUPPLY_PROP_MANUFACTURER,
 215};
 216
 217static enum power_supply_property energy_battery_props[] = {
 218        POWER_SUPPLY_PROP_STATUS,
 219        POWER_SUPPLY_PROP_PRESENT,
 220        POWER_SUPPLY_PROP_TECHNOLOGY,
 221        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 222        POWER_SUPPLY_PROP_VOLTAGE_NOW,
 223        POWER_SUPPLY_PROP_CURRENT_NOW,
 224        POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 225        POWER_SUPPLY_PROP_ENERGY_FULL,
 226        POWER_SUPPLY_PROP_ENERGY_NOW,
 227        POWER_SUPPLY_PROP_MODEL_NAME,
 228        POWER_SUPPLY_PROP_MANUFACTURER,
 229};
 230#endif
 231
 232#ifdef CONFIG_ACPI_PROCFS_POWER
 233inline char *acpi_battery_units(struct acpi_battery *battery)
 234{
 235        return (battery->power_unit)?"mA":"mW";
 236}
 237#endif
 238
 239/* --------------------------------------------------------------------------
 240                               Battery Management
 241   -------------------------------------------------------------------------- */
 242struct acpi_offsets {
 243        size_t offset;          /* offset inside struct acpi_sbs_battery */
 244        u8 mode;                /* int or string? */
 245};
 246
 247static struct acpi_offsets state_offsets[] = {
 248        {offsetof(struct acpi_battery, state), 0},
 249        {offsetof(struct acpi_battery, current_now), 0},
 250        {offsetof(struct acpi_battery, capacity_now), 0},
 251        {offsetof(struct acpi_battery, voltage_now), 0},
 252};
 253
 254static struct acpi_offsets info_offsets[] = {
 255        {offsetof(struct acpi_battery, power_unit), 0},
 256        {offsetof(struct acpi_battery, design_capacity), 0},
 257        {offsetof(struct acpi_battery, full_charge_capacity), 0},
 258        {offsetof(struct acpi_battery, technology), 0},
 259        {offsetof(struct acpi_battery, design_voltage), 0},
 260        {offsetof(struct acpi_battery, design_capacity_warning), 0},
 261        {offsetof(struct acpi_battery, design_capacity_low), 0},
 262        {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 263        {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 264        {offsetof(struct acpi_battery, model_number), 1},
 265        {offsetof(struct acpi_battery, serial_number), 1},
 266        {offsetof(struct acpi_battery, type), 1},
 267        {offsetof(struct acpi_battery, oem_info), 1},
 268};
 269
 270static int extract_package(struct acpi_battery *battery,
 271                           union acpi_object *package,
 272                           struct acpi_offsets *offsets, int num)
 273{
 274        int i;
 275        union acpi_object *element;
 276        if (package->type != ACPI_TYPE_PACKAGE)
 277                return -EFAULT;
 278        for (i = 0; i < num; ++i) {
 279                if (package->package.count <= i)
 280                        return -EFAULT;
 281                element = &package->package.elements[i];
 282                if (offsets[i].mode) {
 283                        u8 *ptr = (u8 *)battery + offsets[i].offset;
 284                        if (element->type == ACPI_TYPE_STRING ||
 285                            element->type == ACPI_TYPE_BUFFER)
 286                                strncpy(ptr, element->string.pointer, 32);
 287                        else if (element->type == ACPI_TYPE_INTEGER) {
 288                                strncpy(ptr, (u8 *)&element->integer.value,
 289                                        sizeof(acpi_integer));
 290                                ptr[sizeof(acpi_integer)] = 0;
 291                        } else return -EFAULT;
 292                } else {
 293                        if (element->type == ACPI_TYPE_INTEGER) {
 294                                int *x = (int *)((u8 *)battery +
 295                                                offsets[i].offset);
 296                                *x = element->integer.value;
 297                        } else return -EFAULT;
 298                }
 299        }
 300        return 0;
 301}
 302
 303static int acpi_battery_get_status(struct acpi_battery *battery)
 304{
 305        if (acpi_bus_get_status(battery->device)) {
 306                ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
 307                return -ENODEV;
 308        }
 309        return 0;
 310}
 311
 312static int acpi_battery_get_info(struct acpi_battery *battery)
 313{
 314        int result = -EFAULT;
 315        acpi_status status = 0;
 316        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 317
 318        if (!acpi_battery_present(battery))
 319                return 0;
 320        mutex_lock(&battery->lock);
 321        status = acpi_evaluate_object(battery->device->handle, "_BIF",
 322                                      NULL, &buffer);
 323        mutex_unlock(&battery->lock);
 324
 325        if (ACPI_FAILURE(status)) {
 326                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
 327                return -ENODEV;
 328        }
 329
 330        result = extract_package(battery, buffer.pointer,
 331                                 info_offsets, ARRAY_SIZE(info_offsets));
 332        kfree(buffer.pointer);
 333        return result;
 334}
 335
 336static int acpi_battery_get_state(struct acpi_battery *battery)
 337{
 338        int result = 0;
 339        acpi_status status = 0;
 340        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 341
 342        if (!acpi_battery_present(battery))
 343                return 0;
 344
 345        if (battery->update_time &&
 346            time_before(jiffies, battery->update_time +
 347                        msecs_to_jiffies(cache_time)))
 348                return 0;
 349
 350        mutex_lock(&battery->lock);
 351        status = acpi_evaluate_object(battery->device->handle, "_BST",
 352                                      NULL, &buffer);
 353        mutex_unlock(&battery->lock);
 354
 355        if (ACPI_FAILURE(status)) {
 356                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
 357                return -ENODEV;
 358        }
 359
 360        result = extract_package(battery, buffer.pointer,
 361                                 state_offsets, ARRAY_SIZE(state_offsets));
 362        battery->update_time = jiffies;
 363        kfree(buffer.pointer);
 364        return result;
 365}
 366
 367static int acpi_battery_set_alarm(struct acpi_battery *battery)
 368{
 369        acpi_status status = 0;
 370        union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
 371        struct acpi_object_list arg_list = { 1, &arg0 };
 372
 373        if (!acpi_battery_present(battery)|| !battery->alarm_present)
 374                return -ENODEV;
 375
 376        arg0.integer.value = battery->alarm;
 377
 378        mutex_lock(&battery->lock);
 379        status = acpi_evaluate_object(battery->device->handle, "_BTP",
 380                                 &arg_list, NULL);
 381        mutex_unlock(&battery->lock);
 382
 383        if (ACPI_FAILURE(status))
 384                return -ENODEV;
 385
 386        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
 387        return 0;
 388}
 389
 390static int acpi_battery_init_alarm(struct acpi_battery *battery)
 391{
 392        acpi_status status = AE_OK;
 393        acpi_handle handle = NULL;
 394
 395        /* See if alarms are supported, and if so, set default */
 396        status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
 397        if (ACPI_FAILURE(status)) {
 398                battery->alarm_present = 0;
 399                return 0;
 400        }
 401        battery->alarm_present = 1;
 402        if (!battery->alarm)
 403                battery->alarm = battery->design_capacity_warning;
 404        return acpi_battery_set_alarm(battery);
 405}
 406
 407#ifdef CONFIG_ACPI_SYSFS_POWER
 408static ssize_t acpi_battery_alarm_show(struct device *dev,
 409                                        struct device_attribute *attr,
 410                                        char *buf)
 411{
 412        struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 413        return sprintf(buf, "%d\n", battery->alarm * 1000);
 414}
 415
 416static ssize_t acpi_battery_alarm_store(struct device *dev,
 417                                        struct device_attribute *attr,
 418                                        const char *buf, size_t count)
 419{
 420        unsigned long x;
 421        struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 422        if (sscanf(buf, "%ld\n", &x) == 1)
 423                battery->alarm = x/1000;
 424        if (acpi_battery_present(battery))
 425                acpi_battery_set_alarm(battery);
 426        return count;
 427}
 428
 429static struct device_attribute alarm_attr = {
 430        .attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE},
 431        .show = acpi_battery_alarm_show,
 432        .store = acpi_battery_alarm_store,
 433};
 434
 435static int sysfs_add_battery(struct acpi_battery *battery)
 436{
 437        int result;
 438
 439        if (battery->power_unit) {
 440                battery->bat.properties = charge_battery_props;
 441                battery->bat.num_properties =
 442                        ARRAY_SIZE(charge_battery_props);
 443        } else {
 444                battery->bat.properties = energy_battery_props;
 445                battery->bat.num_properties =
 446                        ARRAY_SIZE(energy_battery_props);
 447        }
 448
 449        battery->bat.name = acpi_device_bid(battery->device);
 450        battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 451        battery->bat.get_property = acpi_battery_get_property;
 452
 453        result = power_supply_register(&battery->device->dev, &battery->bat);
 454        if (result)
 455                return result;
 456        return device_create_file(battery->bat.dev, &alarm_attr);
 457}
 458
 459static void sysfs_remove_battery(struct acpi_battery *battery)
 460{
 461        if (!battery->bat.dev)
 462                return;
 463        device_remove_file(battery->bat.dev, &alarm_attr);
 464        power_supply_unregister(&battery->bat);
 465        battery->bat.dev = NULL;
 466}
 467#endif
 468
 469static int acpi_battery_update(struct acpi_battery *battery)
 470{
 471        int result;
 472        result = acpi_battery_get_status(battery);
 473        if (result)
 474                return result;
 475#ifdef CONFIG_ACPI_SYSFS_POWER
 476        if (!acpi_battery_present(battery)) {
 477                sysfs_remove_battery(battery);
 478                battery->update_time = 0;
 479                return 0;
 480        }
 481#endif
 482        if (!battery->update_time) {
 483                result = acpi_battery_get_info(battery);
 484                if (result)
 485                        return result;
 486                acpi_battery_init_alarm(battery);
 487        }
 488#ifdef CONFIG_ACPI_SYSFS_POWER
 489        if (!battery->bat.dev)
 490                sysfs_add_battery(battery);
 491#endif
 492        return acpi_battery_get_state(battery);
 493}
 494
 495/* --------------------------------------------------------------------------
 496                              FS Interface (/proc)
 497   -------------------------------------------------------------------------- */
 498
 499#ifdef CONFIG_ACPI_PROCFS_POWER
 500static struct proc_dir_entry *acpi_battery_dir;
 501
 502static int acpi_battery_print_info(struct seq_file *seq, int result)
 503{
 504        struct acpi_battery *battery = seq->private;
 505
 506        if (result)
 507                goto end;
 508
 509        seq_printf(seq, "present:                 %s\n",
 510                   acpi_battery_present(battery)?"yes":"no");
 511        if (!acpi_battery_present(battery))
 512                goto end;
 513        if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 514                seq_printf(seq, "design capacity:         unknown\n");
 515        else
 516                seq_printf(seq, "design capacity:         %d %sh\n",
 517                           battery->design_capacity,
 518                           acpi_battery_units(battery));
 519
 520        if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 521                seq_printf(seq, "last full capacity:      unknown\n");
 522        else
 523                seq_printf(seq, "last full capacity:      %d %sh\n",
 524                           battery->full_charge_capacity,
 525                           acpi_battery_units(battery));
 526
 527        seq_printf(seq, "battery technology:      %srechargeable\n",
 528                   (!battery->technology)?"non-":"");
 529
 530        if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 531                seq_printf(seq, "design voltage:          unknown\n");
 532        else
 533                seq_printf(seq, "design voltage:          %d mV\n",
 534                           battery->design_voltage);
 535        seq_printf(seq, "design capacity warning: %d %sh\n",
 536                   battery->design_capacity_warning,
 537                   acpi_battery_units(battery));
 538        seq_printf(seq, "design capacity low:     %d %sh\n",
 539                   battery->design_capacity_low,
 540                   acpi_battery_units(battery));
 541        seq_printf(seq, "capacity granularity 1:  %d %sh\n",
 542                   battery->capacity_granularity_1,
 543                   acpi_battery_units(battery));
 544        seq_printf(seq, "capacity granularity 2:  %d %sh\n",
 545                   battery->capacity_granularity_2,
 546                   acpi_battery_units(battery));
 547        seq_printf(seq, "model number:            %s\n", battery->model_number);
 548        seq_printf(seq, "serial number:           %s\n", battery->serial_number);
 549        seq_printf(seq, "battery type:            %s\n", battery->type);
 550        seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
 551      end:
 552        if (result)
 553                seq_printf(seq, "ERROR: Unable to read battery info\n");
 554        return result;
 555}
 556
 557static int acpi_battery_print_state(struct seq_file *seq, int result)
 558{
 559        struct acpi_battery *battery = seq->private;
 560
 561        if (result)
 562                goto end;
 563
 564        seq_printf(seq, "present:                 %s\n",
 565                   acpi_battery_present(battery)?"yes":"no");
 566        if (!acpi_battery_present(battery))
 567                goto end;
 568
 569        seq_printf(seq, "capacity state:          %s\n",
 570                        (battery->state & 0x04)?"critical":"ok");
 571        if ((battery->state & 0x01) && (battery->state & 0x02))
 572                seq_printf(seq,
 573                           "charging state:          charging/discharging\n");
 574        else if (battery->state & 0x01)
 575                seq_printf(seq, "charging state:          discharging\n");
 576        else if (battery->state & 0x02)
 577                seq_printf(seq, "charging state:          charging\n");
 578        else
 579                seq_printf(seq, "charging state:          charged\n");
 580
 581        if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
 582                seq_printf(seq, "present rate:            unknown\n");
 583        else
 584                seq_printf(seq, "present rate:            %d %s\n",
 585                           battery->current_now, acpi_battery_units(battery));
 586
 587        if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
 588                seq_printf(seq, "remaining capacity:      unknown\n");
 589        else
 590                seq_printf(seq, "remaining capacity:      %d %sh\n",
 591                           battery->capacity_now, acpi_battery_units(battery));
 592        if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
 593                seq_printf(seq, "present voltage:         unknown\n");
 594        else
 595                seq_printf(seq, "present voltage:         %d mV\n",
 596                           battery->voltage_now);
 597      end:
 598        if (result)
 599                seq_printf(seq, "ERROR: Unable to read battery state\n");
 600
 601        return result;
 602}
 603
 604static int acpi_battery_print_alarm(struct seq_file *seq, int result)
 605{
 606        struct acpi_battery *battery = seq->private;
 607
 608        if (result)
 609                goto end;
 610
 611        if (!acpi_battery_present(battery)) {
 612                seq_printf(seq, "present:                 no\n");
 613                goto end;
 614        }
 615        seq_printf(seq, "alarm:                   ");
 616        if (!battery->alarm)
 617                seq_printf(seq, "unsupported\n");
 618        else
 619                seq_printf(seq, "%u %sh\n", battery->alarm,
 620                                acpi_battery_units(battery));
 621      end:
 622        if (result)
 623                seq_printf(seq, "ERROR: Unable to read battery alarm\n");
 624        return result;
 625}
 626
 627static ssize_t acpi_battery_write_alarm(struct file *file,
 628                                        const char __user * buffer,
 629                                        size_t count, loff_t * ppos)
 630{
 631        int result = 0;
 632        char alarm_string[12] = { '\0' };
 633        struct seq_file *m = file->private_data;
 634        struct acpi_battery *battery = m->private;
 635
 636        if (!battery || (count > sizeof(alarm_string) - 1))
 637                return -EINVAL;
 638        if (!acpi_battery_present(battery)) {
 639                result = -ENODEV;
 640                goto end;
 641        }
 642        if (copy_from_user(alarm_string, buffer, count)) {
 643                result = -EFAULT;
 644                goto end;
 645        }
 646        alarm_string[count] = '\0';
 647        battery->alarm = simple_strtol(alarm_string, NULL, 0);
 648        result = acpi_battery_set_alarm(battery);
 649      end:
 650        if (!result)
 651                return count;
 652        return result;
 653}
 654
 655typedef int(*print_func)(struct seq_file *seq, int result);
 656
 657static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
 658        acpi_battery_print_info,
 659        acpi_battery_print_state,
 660        acpi_battery_print_alarm,
 661};
 662
 663static int acpi_battery_read(int fid, struct seq_file *seq)
 664{
 665        struct acpi_battery *battery = seq->private;
 666        int result = acpi_battery_update(battery);
 667        return acpi_print_funcs[fid](seq, result);
 668}
 669
 670#define DECLARE_FILE_FUNCTIONS(_name) \
 671static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
 672{ \
 673        return acpi_battery_read(_name##_tag, seq); \
 674} \
 675static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
 676{ \
 677        return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
 678}
 679
 680DECLARE_FILE_FUNCTIONS(info);
 681DECLARE_FILE_FUNCTIONS(state);
 682DECLARE_FILE_FUNCTIONS(alarm);
 683
 684#undef DECLARE_FILE_FUNCTIONS
 685
 686#define FILE_DESCRIPTION_RO(_name) \
 687        { \
 688        .name = __stringify(_name), \
 689        .mode = S_IRUGO, \
 690        .ops = { \
 691                .open = acpi_battery_##_name##_open_fs, \
 692                .read = seq_read, \
 693                .llseek = seq_lseek, \
 694                .release = single_release, \
 695                .owner = THIS_MODULE, \
 696                }, \
 697        }
 698
 699#define FILE_DESCRIPTION_RW(_name) \
 700        { \
 701        .name = __stringify(_name), \
 702        .mode = S_IFREG | S_IRUGO | S_IWUSR, \
 703        .ops = { \
 704                .open = acpi_battery_##_name##_open_fs, \
 705                .read = seq_read, \
 706                .llseek = seq_lseek, \
 707                .write = acpi_battery_write_##_name, \
 708                .release = single_release, \
 709                .owner = THIS_MODULE, \
 710                }, \
 711        }
 712
 713static struct battery_file {
 714        struct file_operations ops;
 715        mode_t mode;
 716        char *name;
 717} acpi_battery_file[] = {
 718        FILE_DESCRIPTION_RO(info),
 719        FILE_DESCRIPTION_RO(state),
 720        FILE_DESCRIPTION_RW(alarm),
 721};
 722
 723#undef FILE_DESCRIPTION_RO
 724#undef FILE_DESCRIPTION_RW
 725
 726static int acpi_battery_add_fs(struct acpi_device *device)
 727{
 728        struct proc_dir_entry *entry = NULL;
 729        int i;
 730
 731        if (!acpi_device_dir(device)) {
 732                acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 733                                                     acpi_battery_dir);
 734                if (!acpi_device_dir(device))
 735                        return -ENODEV;
 736                acpi_device_dir(device)->owner = THIS_MODULE;
 737        }
 738
 739        for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
 740                entry = create_proc_entry(acpi_battery_file[i].name,
 741                                  acpi_battery_file[i].mode, acpi_device_dir(device));
 742                if (!entry)
 743                        return -ENODEV;
 744                else {
 745                        entry->proc_fops = &acpi_battery_file[i].ops;
 746                        entry->data = acpi_driver_data(device);
 747                        entry->owner = THIS_MODULE;
 748                }
 749        }
 750        return 0;
 751}
 752
 753static void acpi_battery_remove_fs(struct acpi_device *device)
 754{
 755        int i;
 756        if (!acpi_device_dir(device))
 757                return;
 758        for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
 759                remove_proc_entry(acpi_battery_file[i].name,
 760                                  acpi_device_dir(device));
 761
 762        remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
 763        acpi_device_dir(device) = NULL;
 764}
 765
 766#endif
 767
 768/* --------------------------------------------------------------------------
 769                                 Driver Interface
 770   -------------------------------------------------------------------------- */
 771
 772static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
 773{
 774        struct acpi_battery *battery = data;
 775        struct acpi_device *device;
 776        if (!battery)
 777                return;
 778        device = battery->device;
 779        acpi_battery_update(battery);
 780        acpi_bus_generate_proc_event(device, event,
 781                                     acpi_battery_present(battery));
 782        acpi_bus_generate_netlink_event(device->pnp.device_class,
 783                                        device->dev.bus_id, event,
 784                                        acpi_battery_present(battery));
 785#ifdef CONFIG_ACPI_SYSFS_POWER
 786        /* acpi_batter_update could remove power_supply object */
 787        if (battery->bat.dev)
 788                kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
 789#endif
 790}
 791
 792static int acpi_battery_add(struct acpi_device *device)
 793{
 794        int result = 0;
 795        acpi_status status = 0;
 796        struct acpi_battery *battery = NULL;
 797        if (!device)
 798                return -EINVAL;
 799        battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
 800        if (!battery)
 801                return -ENOMEM;
 802        battery->device = device;
 803        strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
 804        strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 805        acpi_driver_data(device) = battery;
 806        mutex_init(&battery->lock);
 807        acpi_battery_update(battery);
 808#ifdef CONFIG_ACPI_PROCFS_POWER
 809        result = acpi_battery_add_fs(device);
 810        if (result)
 811                goto end;
 812#endif
 813        status = acpi_install_notify_handler(device->handle,
 814                                             ACPI_ALL_NOTIFY,
 815                                             acpi_battery_notify, battery);
 816        if (ACPI_FAILURE(status)) {
 817                ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
 818                result = -ENODEV;
 819                goto end;
 820        }
 821        printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
 822               ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
 823               device->status.battery_present ? "present" : "absent");
 824      end:
 825        if (result) {
 826#ifdef CONFIG_ACPI_PROCFS_POWER
 827                acpi_battery_remove_fs(device);
 828#endif
 829                kfree(battery);
 830        }
 831        return result;
 832}
 833
 834static int acpi_battery_remove(struct acpi_device *device, int type)
 835{
 836        acpi_status status = 0;
 837        struct acpi_battery *battery = NULL;
 838
 839        if (!device || !acpi_driver_data(device))
 840                return -EINVAL;
 841        battery = acpi_driver_data(device);
 842        status = acpi_remove_notify_handler(device->handle,
 843                                            ACPI_ALL_NOTIFY,
 844                                            acpi_battery_notify);
 845#ifdef CONFIG_ACPI_PROCFS_POWER
 846        acpi_battery_remove_fs(device);
 847#endif
 848#ifdef CONFIG_ACPI_SYSFS_POWER
 849        sysfs_remove_battery(battery);
 850#endif
 851        mutex_destroy(&battery->lock);
 852        kfree(battery);
 853        return 0;
 854}
 855
 856/* this is needed to learn about changes made in suspended state */
 857static int acpi_battery_resume(struct acpi_device *device)
 858{
 859        struct acpi_battery *battery;
 860        if (!device)
 861                return -EINVAL;
 862        battery = acpi_driver_data(device);
 863        battery->update_time = 0;
 864        acpi_battery_update(battery);
 865        return 0;
 866}
 867
 868static struct acpi_driver acpi_battery_driver = {
 869        .name = "battery",
 870        .class = ACPI_BATTERY_CLASS,
 871        .ids = battery_device_ids,
 872        .ops = {
 873                .add = acpi_battery_add,
 874                .resume = acpi_battery_resume,
 875                .remove = acpi_battery_remove,
 876                },
 877};
 878
 879static int __init acpi_battery_init(void)
 880{
 881        if (acpi_disabled)
 882                return -ENODEV;
 883#ifdef CONFIG_ACPI_PROCFS_POWER
 884        acpi_battery_dir = acpi_lock_battery_dir();
 885        if (!acpi_battery_dir)
 886                return -ENODEV;
 887#endif
 888        if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
 889#ifdef CONFIG_ACPI_PROCFS_POWER
 890                acpi_unlock_battery_dir(acpi_battery_dir);
 891#endif
 892                return -ENODEV;
 893        }
 894        return 0;
 895}
 896
 897static void __exit acpi_battery_exit(void)
 898{
 899        acpi_bus_unregister_driver(&acpi_battery_driver);
 900#ifdef CONFIG_ACPI_PROCFS_POWER
 901        acpi_unlock_battery_dir(acpi_battery_dir);
 902#endif
 903}
 904
 905module_init(acpi_battery_init);
 906module_exit(acpi_battery_exit);
 907