drivers/acpi/battery.c

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