SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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_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_CLASS              "battery"
  50 #define ACPI_BATTERY_DEVICE_NAME        "Battery"
  51 #define ACPI_BATTERY_NOTIFY_STATUS      0x80
  52 #define ACPI_BATTERY_NOTIFY_INFO        0x81
  53
  54 #define _COMPONENT              ACPI_BATTERY_COMPONENT
  55
  56 ACPI_MODULE_NAME("battery");
  57
  58 MODULE_AUTHOR("Paul Diefenbaugh");
  59 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
  60 MODULE_DESCRIPTION("ACPI Battery Driver");
  61 MODULE_LICENSE("GPL");
  62
  63 static unsigned int cache_time = 1000;
  64 module_param(cache_time, uint, 0644);
  65 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  66
  67 #ifdef CONFIG_ACPI_PROCFS_POWER
  68 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
  69 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
  70
  71 enum acpi_battery_files {
  72         info_tag = 0,
  73         state_tag,
  74         alarm_tag,
  75         ACPI_BATTERY_NUMFILES,
  76 };
  77
  78 #endif
  79
  80 static const struct acpi_device_id battery_device_ids[] = {
  81         {"PNP0C0A", 0},
  82         {"", 0},
  83 };
  84
  85 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
  86
  87
  88 struct acpi_battery {
  89         struct mutex lock;
  90 #ifdef CONFIG_ACPI_SYSFS_POWER
  91         struct power_supply bat;
  92 #endif
  93         struct acpi_device *device;
  94         unsigned long update_time;
  95         int current_now;
  96         int capacity_now;
  97         int voltage_now;
  98         int design_capacity;
  99         int full_charge_capacity;
 100         int technology;
 101         int design_voltage;
 102         int design_capacity_warning;
 103         int design_capacity_low;
 104         int capacity_granularity_1;
 105         int capacity_granularity_2;
 106         int alarm;
 107         char model_number[32];
 108         char serial_number[32];
 109         char type[32];
 110         char oem_info[32];
 111         int state;
 112         int power_unit;
 113         u8 alarm_present;
 114 };
 115
 116 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
 117
 118 inline int acpi_battery_present(struct acpi_battery *battery)
 119 {
 120         return battery->device->status.battery_present;
 121 }
 122
 123 #ifdef CONFIG_ACPI_SYSFS_POWER
 124 static int acpi_battery_technology(struct acpi_battery *battery)
 125 {
 126         if (!strcasecmp("NiCd", battery->type))
 127                 return POWER_SUPPLY_TECHNOLOGY_NiCd;
 128         if (!strcasecmp("NiMH", battery->type))
 129                 return POWER_SUPPLY_TECHNOLOGY_NiMH;
 130         if (!strcasecmp("LION", battery->type))
 131                 return POWER_SUPPLY_TECHNOLOGY_LION;
 132         if (!strncasecmp("LI-ION", battery->type, 6))
 133                 return POWER_SUPPLY_TECHNOLOGY_LION;
 134         if (!strcasecmp("LiP", battery->type))
 135                 return POWER_SUPPLY_TECHNOLOGY_LIPO;
 136         return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 137 }
 138
 139 static int acpi_battery_get_state(struct acpi_battery *battery);
 140
 141 static int acpi_battery_get_property(struct power_supply *psy,
 142                                      enum power_supply_property psp,
 143                                      union power_supply_propval *val)
 144 {
 145         struct acpi_battery *battery = to_acpi_battery(psy);
 146
 147         if (acpi_battery_present(battery)) {
 148                 /* run battery update only if it is present */
 149                 acpi_battery_get_state(battery);
 150         } else if (psp != POWER_SUPPLY_PROP_PRESENT)
 151                 return -ENODEV;
 152         switch (psp) {
 153         case POWER_SUPPLY_PROP_STATUS:
 154                 if (battery->state & 0x01)
 155                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 156                 else if (battery->state & 0x02)
 157                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 158                 else if (battery->state == 0)
 159                         val->intval = POWER_SUPPLY_STATUS_FULL;
 160                 else
 161                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 162                 break;
 163         case POWER_SUPPLY_PROP_PRESENT:
 164                 val->intval = acpi_battery_present(battery);
 165                 break;
 166         case POWER_SUPPLY_PROP_TECHNOLOGY:
 167                 val->intval = acpi_battery_technology(battery);
 168                 break;
 169         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 170                 val->intval = battery->design_voltage * 1000;
 171                 break;
 172         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 173                 val->intval = battery->voltage_now * 1000;
 174                 break;
 175         case POWER_SUPPLY_PROP_CURRENT_NOW:
 176                 val->intval = battery->current_now * 1000;
 177                 /* if power units are mW, convert to mA by
 178                    dividing by current voltage (mV/1000) */
 179                 if (!battery->power_unit) {
 180                         if (battery->voltage_now) {
 181                                 val->intval /= battery->voltage_now;
 182                                 val->intval *= 1000;
 183                         } else
 184                                 val->intval = -1;
 185                 }
 186                 break;
 187         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 188         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
 189                 val->intval = battery->design_capacity * 1000;
 190                 break;
 191         case POWER_SUPPLY_PROP_CHARGE_FULL:
 192         case POWER_SUPPLY_PROP_ENERGY_FULL:
 193                 val->intval = battery->full_charge_capacity * 1000;
 194                 break;
 195         case POWER_SUPPLY_PROP_CHARGE_NOW:
 196         case POWER_SUPPLY_PROP_ENERGY_NOW:
 197                 val->intval = battery->capacity_now * 1000;
 198                 break;
 199         case POWER_SUPPLY_PROP_MODEL_NAME:
 200                 val->strval = battery->model_number;
 201                 break;
 202         case POWER_SUPPLY_PROP_MANUFACTURER:
 203                 val->strval = battery->oem_info;
 204                 break;
 205         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 206                 val->strval = battery->serial_number;
 207                 break;
 208         default:
 209                 return -EINVAL;
 210         }
 211         return 0;
 212 }
 213
 214 static enum power_supply_property charge_battery_props[] = {
 215         POWER_SUPPLY_PROP_STATUS,
 216         POWER_SUPPLY_PROP_PRESENT,
 217         POWER_SUPPLY_PROP_TECHNOLOGY,
 218         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 219         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 220         POWER_SUPPLY_PROP_CURRENT_NOW,
 221         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 222         POWER_SUPPLY_PROP_CHARGE_FULL,
 223         POWER_SUPPLY_PROP_CHARGE_NOW,
 224         POWER_SUPPLY_PROP_MODEL_NAME,
 225         POWER_SUPPLY_PROP_MANUFACTURER,
 226         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 227 };
 228
 229 static enum power_supply_property energy_battery_props[] = {
 230         POWER_SUPPLY_PROP_STATUS,
 231         POWER_SUPPLY_PROP_PRESENT,
 232         POWER_SUPPLY_PROP_TECHNOLOGY,
 233         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
 234         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 235         POWER_SUPPLY_PROP_CURRENT_NOW,
 236         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 237         POWER_SUPPLY_PROP_ENERGY_FULL,
 238         POWER_SUPPLY_PROP_ENERGY_NOW,
 239         POWER_SUPPLY_PROP_MODEL_NAME,
 240         POWER_SUPPLY_PROP_MANUFACTURER,
 241         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 242 };
 243 #endif
 244
 245 #ifdef CONFIG_ACPI_PROCFS_POWER
 246 inline char *acpi_battery_units(struct acpi_battery *battery)
 247 {
 248         return (battery->power_unit)?"mA":"mW";
 249 }
 250 #endif
 251
 252 /* --------------------------------------------------------------------------
 253                                Battery Management
 254    -------------------------------------------------------------------------- */
 255 struct acpi_offsets {
 256         size_t offset;          /* offset inside struct acpi_sbs_battery */
 257         u8 mode;                /* int or string? */
 258 };
 259
 260 static struct acpi_offsets state_offsets[] = {
 261         {offsetof(struct acpi_battery, state), 0},
 262         {offsetof(struct acpi_battery, current_now), 0},
 263         {offsetof(struct acpi_battery, capacity_now), 0},
 264         {offsetof(struct acpi_battery, voltage_now), 0},
 265 };
 266
 267 static struct acpi_offsets info_offsets[] = {
 268         {offsetof(struct acpi_battery, power_unit), 0},
 269         {offsetof(struct acpi_battery, design_capacity), 0},
 270         {offsetof(struct acpi_battery, full_charge_capacity), 0},
 271         {offsetof(struct acpi_battery, technology), 0},
 272         {offsetof(struct acpi_battery, design_voltage), 0},
 273         {offsetof(struct acpi_battery, design_capacity_warning), 0},
 274         {offsetof(struct acpi_battery, design_capacity_low), 0},
 275         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
 276         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
 277         {offsetof(struct acpi_battery, model_number), 1},
 278         {offsetof(struct acpi_battery, serial_number), 1},
 279         {offsetof(struct acpi_battery, type), 1},
 280         {offsetof(struct acpi_battery, oem_info), 1},
 281 };
 282
 283 static int extract_package(struct acpi_battery *battery,
 284                            union acpi_object *package,
 285                            struct acpi_offsets *offsets, int num)
 286 {
 287         int i;
 288         union acpi_object *element;
 289         if (package->type != ACPI_TYPE_PACKAGE)
 290                 return -EFAULT;
 291         for (i = 0; i < num; ++i) {
 292                 if (package->package.count <= i)
 293                         return -EFAULT;
 294                 element = &package->package.elements[i];
 295                 if (offsets[i].mode) {
 296                         u8 *ptr = (u8 *)battery + offsets[i].offset;
 297                         if (element->type == ACPI_TYPE_STRING ||
 298                             element->type == ACPI_TYPE_BUFFER)
 299                                 strncpy(ptr, element->string.pointer, 32);
 300                         else if (element->type == ACPI_TYPE_INTEGER) {
 301                                 strncpy(ptr, (u8 *)&element->integer.value,
 302                                         sizeof(acpi_integer));
 303                                 ptr[sizeof(acpi_integer)] = 0;
 304                         } else
 305                                 *ptr = 0; /* don't have value */
 306                 } else {
 307                         int *x = (int *)((u8 *)battery + offsets[i].offset);
 308                         *x = (element->type == ACPI_TYPE_INTEGER) ?
 309                                 element->integer.value : -1;
 310                 }
 311         }
 312         return 0;
 313 }
 314
 315 static int acpi_battery_get_status(struct acpi_battery *battery)
 316 {
 317         if (acpi_bus_get_status(battery->device)) {
 318                 ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
 319                 return -ENODEV;
 320         }
 321         return 0;
 322 }
 323
 324 static int acpi_battery_get_info(struct acpi_battery *battery)
 325 {
 326         int result = -EFAULT;
 327         acpi_status status = 0;
 328         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 329
 330         if (!acpi_battery_present(battery))
 331                 return 0;
 332         mutex_lock(&battery->lock);
 333         status = acpi_evaluate_object(battery->device->handle, "_BIF",
 334                                       NULL, &buffer);
 335         mutex_unlock(&battery->lock);
 336
 337         if (ACPI_FAILURE(status)) {
 338                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
 339                 return -ENODEV;
 340         }
 341
 342         result = extract_package(battery, buffer.pointer,
 343                                  info_offsets, ARRAY_SIZE(info_offsets));
 344         kfree(buffer.pointer);
 345         return result;
 346 }
 347
 348 static int acpi_battery_get_state(struct acpi_battery *battery)
 349 {
 350         int result = 0;
 351         acpi_status status = 0;
 352         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 353
 354         if (!acpi_battery_present(battery))
 355                 return 0;
 356
 357         if (battery->update_time &&
 358             time_before(jiffies, battery->update_time +
 359                         msecs_to_jiffies(cache_time)))
 360                 return 0;
 361
 362         mutex_lock(&battery->lock);
 363         status = acpi_evaluate_object(battery->device->handle, "_BST",
 364                                       NULL, &buffer);
 365         mutex_unlock(&battery->lock);
 366
 367         if (ACPI_FAILURE(status)) {
 368                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
 369                 return -ENODEV;
 370         }
 371
 372         result = extract_package(battery, buffer.pointer,
 373                                  state_offsets, ARRAY_SIZE(state_offsets));
 374         battery->update_time = jiffies;
 375         kfree(buffer.pointer);
 376         return result;
 377 }
 378
 379 static int acpi_battery_set_alarm(struct acpi_battery *battery)
 380 {
 381         acpi_status status = 0;
 382         union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
 383         struct acpi_object_list arg_list = { 1, &arg0 };
 384
 385         if (!acpi_battery_present(battery)|| !battery->alarm_present)
 386                 return -ENODEV;
 387
 388         arg0.integer.value = battery->alarm;
 389
 390         mutex_lock(&battery->lock);
 391         status = acpi_evaluate_object(battery->device->handle, "_BTP",
 392                                  &arg_list, NULL);
 393         mutex_unlock(&battery->lock);
 394
 395         if (ACPI_FAILURE(status))
 396                 return -ENODEV;
 397
 398         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
 399         return 0;
 400 }
 401
 402 static int acpi_battery_init_alarm(struct acpi_battery *battery)
 403 {
 404         acpi_status status = AE_OK;
 405         acpi_handle handle = NULL;
 406
 407         /* See if alarms are supported, and if so, set default */
 408         status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
 409         if (ACPI_FAILURE(status)) {
 410                 battery->alarm_present = 0;
 411                 return 0;
 412         }
 413         battery->alarm_present = 1;
 414         if (!battery->alarm)
 415                 battery->alarm = battery->design_capacity_warning;
 416         return acpi_battery_set_alarm(battery);
 417 }
 418
 419 #ifdef CONFIG_ACPI_SYSFS_POWER
 420 static ssize_t acpi_battery_alarm_show(struct device *dev,
 421                                         struct device_attribute *attr,
 422                                         char *buf)
 423 {
 424         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 425         return sprintf(buf, "%d\n", battery->alarm * 1000);
 426 }
 427
 428 static ssize_t acpi_battery_alarm_store(struct device *dev,
 429                                         struct device_attribute *attr,
 430                                         const char *buf, size_t count)
 431 {
 432         unsigned long x;
 433         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
 434         if (sscanf(buf, "%ld\n", &x) == 1)
 435                 battery->alarm = x/1000;
 436         if (acpi_battery_present(battery))
 437                 acpi_battery_set_alarm(battery);
 438         return count;
 439 }
 440
 441 static struct device_attribute alarm_attr = {
 442         .attr = {.name = "alarm", .mode = 0644},
 443         .show = acpi_battery_alarm_show,
 444         .store = acpi_battery_alarm_store,
 445 };
 446
 447 static int sysfs_add_battery(struct acpi_battery *battery)
 448 {
 449         int result;
 450
 451         if (battery->power_unit) {
 452                 battery->bat.properties = charge_battery_props;
 453                 battery->bat.num_properties =
 454                         ARRAY_SIZE(charge_battery_props);
 455         } else {
 456                 battery->bat.properties = energy_battery_props;
 457                 battery->bat.num_properties =
 458                         ARRAY_SIZE(energy_battery_props);
 459         }
 460
 461         battery->bat.name = acpi_device_bid(battery->device);
 462         battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 463         battery->bat.get_property = acpi_battery_get_property;
 464
 465         result = power_supply_register(&battery->device->dev, &battery->bat);
 466         if (result)
 467                 return result;
 468         return device_create_file(battery->bat.dev, &alarm_attr);
 469 }
 470
 471 static void sysfs_remove_battery(struct acpi_battery *battery)
 472 {
 473         if (!battery->bat.dev)
 474                 return;
 475         device_remove_file(battery->bat.dev, &alarm_attr);
 476         power_supply_unregister(&battery->bat);
 477         battery->bat.dev = NULL;
 478 }
 479 #endif
 480
 481 static int acpi_battery_update(struct acpi_battery *battery)
 482 {
 483         int result;
 484         result = acpi_battery_get_status(battery);
 485         if (result)
 486                 return result;
 487 #ifdef CONFIG_ACPI_SYSFS_POWER
 488         if (!acpi_battery_present(battery)) {
 489                 sysfs_remove_battery(battery);
 490                 battery->update_time = 0;
 491                 return 0;
 492         }
 493 #endif
 494         if (!battery->update_time) {
 495                 result = acpi_battery_get_info(battery);
 496                 if (result)
 497                         return result;
 498                 acpi_battery_init_alarm(battery);
 499         }
 500 #ifdef CONFIG_ACPI_SYSFS_POWER
 501         if (!battery->bat.dev)
 502                 sysfs_add_battery(battery);
 503 #endif
 504         return acpi_battery_get_state(battery);
 505 }
 506
 507 /* --------------------------------------------------------------------------
 508                               FS Interface (/proc)
 509    -------------------------------------------------------------------------- */
 510
 511 #ifdef CONFIG_ACPI_PROCFS_POWER
 512 static struct proc_dir_entry *acpi_battery_dir;
 513
 514 static int acpi_battery_print_info(struct seq_file *seq, int result)
 515 {
 516         struct acpi_battery *battery = seq->private;
 517
 518         if (result)
 519                 goto end;
 520
 521         seq_printf(seq, "present:                 %s\n",
 522                    acpi_battery_present(battery)?"yes":"no");
 523         if (!acpi_battery_present(battery))
 524                 goto end;
 525         if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 526                 seq_printf(seq, "design capacity:         unknown\n");
 527         else
 528                 seq_printf(seq, "design capacity:         %d %sh\n",
 529                            battery->design_capacity,
 530                            acpi_battery_units(battery));
 531
 532         if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 533                 seq_printf(seq, "last full capacity:      unknown\n");
 534         else
 535                 seq_printf(seq, "last full capacity:      %d %sh\n",
 536                            battery->full_charge_capacity,
 537                            acpi_battery_units(battery));
 538
 539         seq_printf(seq, "battery technology:      %srechargeable\n",
 540                    (!battery->technology)?"non-":"");
 541
 542         if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 543                 seq_printf(seq, "design voltage:          unknown\n");
 544         else
 545                 seq_printf(seq, "design voltage:          %d mV\n",
 546                            battery->design_voltage);
 547         seq_printf(seq, "design capacity warning: %d %sh\n",
 548                    battery->design_capacity_warning,
 549                    acpi_battery_units(battery));
 550         seq_printf(seq, "design capacity low:     %d %sh\n",
 551                    battery->design_capacity_low,
 552                    acpi_battery_units(battery));
 553         seq_printf(seq, "capacity granularity 1:  %d %sh\n",
 554                    battery->capacity_granularity_1,
 555                    acpi_battery_units(battery));
 556         seq_printf(seq, "capacity granularity 2:  %d %sh\n",
 557                    battery->capacity_granularity_2,
 558                    acpi_battery_units(battery));
 559         seq_printf(seq, "model number:            %s\n", battery->model_number);
 560         seq_printf(seq, "serial number:           %s\n", battery->serial_number);
 561         seq_printf(seq, "battery type:            %s\n", battery->type);
 562         seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
 563       end:
 564         if (result)
 565                 seq_printf(seq, "ERROR: Unable to read battery info\n");
 566         return result;
 567 }
 568
 569 static int acpi_battery_print_state(struct seq_file *seq, int result)
 570 {
 571         struct acpi_battery *battery = seq->private;
 572
 573         if (result)
 574                 goto end;
 575
 576         seq_printf(seq, "present:                 %s\n",
 577                    acpi_battery_present(battery)?"yes":"no");
 578         if (!acpi_battery_present(battery))
 579                 goto end;
 580
 581         seq_printf(seq, "capacity state:          %s\n",
 582                         (battery->state & 0x04)?"critical":"ok");
 583         if ((battery->state & 0x01) && (battery->state & 0x02))
 584                 seq_printf(seq,
 585                            "charging state:          charging/discharging\n");
 586         else if (battery->state & 0x01)
 587                 seq_printf(seq, "charging state:          discharging\n");
 588         else if (battery->state & 0x02)
 589                 seq_printf(seq, "charging state:          charging\n");
 590         else
 591                 seq_printf(seq, "charging state:          charged\n");
 592
 593         if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
 594                 seq_printf(seq, "present rate:            unknown\n");
 595         else
 596                 seq_printf(seq, "present rate:            %d %s\n",
 597                            battery->current_now, acpi_battery_units(battery));
 598
 599         if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
 600                 seq_printf(seq, "remaining capacity:      unknown\n");
 601         else
 602                 seq_printf(seq, "remaining capacity:      %d %sh\n",
 603                            battery->capacity_now, acpi_battery_units(battery));
 604         if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
 605                 seq_printf(seq, "present voltage:         unknown\n");
 606         else
 607                 seq_printf(seq, "present voltage:         %d mV\n",
 608                            battery->voltage_now);
 609       end:
 610         if (result)
 611                 seq_printf(seq, "ERROR: Unable to read battery state\n");
 612
 613         return result;
 614 }
 615
 616 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
 617 {
 618         struct acpi_battery *battery = seq->private;
 619
 620         if (result)
 621                 goto end;
 622
 623         if (!acpi_battery_present(battery)) {
 624                 seq_printf(seq, "present:                 no\n");
 625                 goto end;
 626         }
 627         seq_printf(seq, "alarm:                   ");
 628         if (!battery->alarm)
 629                 seq_printf(seq, "unsupported\n");
 630         else
 631                 seq_printf(seq, "%u %sh\n", battery->alarm,
 632                                 acpi_battery_units(battery));
 633       end:
 634         if (result)
 635                 seq_printf(seq, "ERROR: Unable to read battery alarm\n");
 636         return result;
 637 }
 638
 639 static ssize_t acpi_battery_write_alarm(struct file *file,
 640                                         const char __user * buffer,
 641                                         size_t count, loff_t * ppos)
 642 {
 643         int result = 0;
 644         char alarm_string[12] = { '\0' };
 645         struct seq_file *m = file->private_data;
 646         struct acpi_battery *battery = m->private;
 647
 648         if (!battery || (count > sizeof(alarm_string) - 1))
 649                 return -EINVAL;
 650         if (!acpi_battery_present(battery)) {
 651                 result = -ENODEV;
 652                 goto end;
 653         }
 654         if (copy_from_user(alarm_string, buffer, count)) {
 655                 result = -EFAULT;
 656                 goto end;
 657         }
 658         alarm_string[count] = '\0';
 659         battery->alarm = simple_strtol(alarm_string, NULL, 0);
 660         result = acpi_battery_set_alarm(battery);
 661       end:
 662         if (!result)
 663                 return count;
 664         return result;
 665 }
 666
 667 typedef int(*print_func)(struct seq_file *seq, int result);
 668
 669 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
 670         acpi_battery_print_info,
 671         acpi_battery_print_state,
 672         acpi_battery_print_alarm,
 673 };
 674
 675 static int acpi_battery_read(int fid, struct seq_file *seq)
 676 {
 677         struct acpi_battery *battery = seq->private;
 678         int result = acpi_battery_update(battery);
 679         return acpi_print_funcs[fid](seq, result);
 680 }
 681
 682 #define DECLARE_FILE_FUNCTIONS(_name) \
 683 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
 684 { \
 685         return acpi_battery_read(_name##_tag, seq); \
 686 } \
 687 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
 688 { \
 689         return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
 690 }
 691
 692 DECLARE_FILE_FUNCTIONS(info);
 693 DECLARE_FILE_FUNCTIONS(state);
 694 DECLARE_FILE_FUNCTIONS(alarm);
 695
 696 #undef DECLARE_FILE_FUNCTIONS
 697
 698 #define FILE_DESCRIPTION_RO(_name) \
 699         { \
 700         .name = __stringify(_name), \
 701         .mode = S_IRUGO, \
 702         .ops = { \
 703                 .open = acpi_battery_##_name##_open_fs, \
 704                 .read = seq_read, \
 705                 .llseek = seq_lseek, \
 706                 .release = single_release, \
 707                 .owner = THIS_MODULE, \
 708                 }, \
 709         }
 710
 711 #define FILE_DESCRIPTION_RW(_name) \
 712         { \
 713         .name = __stringify(_name), \
 714         .mode = S_IFREG | S_IRUGO | S_IWUSR, \
 715         .ops = { \
 716                 .open = acpi_battery_##_name##_open_fs, \
 717                 .read = seq_read, \
 718                 .llseek = seq_lseek, \
 719                 .write = acpi_battery_write_##_name, \
 720                 .release = single_release, \
 721                 .owner = THIS_MODULE, \
 722                 }, \
 723         }
 724
 725 static struct battery_file {
 726         struct file_operations ops;
 727         mode_t mode;
 728         char *name;
 729 } acpi_battery_file[] = {
 730         FILE_DESCRIPTION_RO(info),
 731         FILE_DESCRIPTION_RO(state),
 732         FILE_DESCRIPTION_RW(alarm),
 733 };
 734
 735 #undef FILE_DESCRIPTION_RO
 736 #undef FILE_DESCRIPTION_RW
 737
 738 static int acpi_battery_add_fs(struct acpi_device *device)
 739 {
 740         struct proc_dir_entry *entry = NULL;
 741         int i;
 742
 743         if (!acpi_device_dir(device)) {
 744                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 745                                                      acpi_battery_dir);
 746                 if (!acpi_device_dir(device))
 747                         return -ENODEV;
 748                 acpi_device_dir(device)->owner = THIS_MODULE;
 749         }
 750
 751         for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
 752                 entry = proc_create_data(acpi_battery_file[i].name,
 753                                          acpi_battery_file[i].mode,
 754                                          acpi_device_dir(device),
 755                                          &acpi_battery_file[i].ops,
 756                                          acpi_driver_data(device));
 757                 if (!entry)
 758                         return -ENODEV;
 759         }
 760         return 0;
 761 }
 762
 763 static void acpi_battery_remove_fs(struct acpi_device *device)
 764 {
 765         int i;
 766         if (!acpi_device_dir(device))
 767                 return;
 768         for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
 769                 remove_proc_entry(acpi_battery_file[i].name,
 770                                   acpi_device_dir(device));
 771
 772         remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
 773         acpi_device_dir(device) = NULL;
 774 }
 775
 776 #endif
 777
 778 /* --------------------------------------------------------------------------
 779                                  Driver Interface
 780    -------------------------------------------------------------------------- */
 781
 782 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
 783 {
 784         struct acpi_battery *battery = data;
 785         struct acpi_device *device;
 786         if (!battery)
 787                 return;
 788         device = battery->device;
 789         acpi_battery_update(battery);
 790         acpi_bus_generate_proc_event(device, event,
 791                                      acpi_battery_present(battery));
 792         acpi_bus_generate_netlink_event(device->pnp.device_class,
 793                                         dev_name(&device->dev), event,
 794                                         acpi_battery_present(battery));
 795 #ifdef CONFIG_ACPI_SYSFS_POWER
 796         /* acpi_batter_update could remove power_supply object */
 797         if (battery->bat.dev)
 798                 kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
 799 #endif
 800 }
 801
 802 static int acpi_battery_add(struct acpi_device *device)
 803 {
 804         int result = 0;
 805         acpi_status status = 0;
 806         struct acpi_battery *battery = NULL;
 807         if (!device)
 808                 return -EINVAL;
 809         battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
 810         if (!battery)
 811                 return -ENOMEM;
 812         battery->device = device;
 813         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
 814         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 815         device->driver_data = battery;
 816         mutex_init(&battery->lock);
 817         acpi_battery_update(battery);
 818 #ifdef CONFIG_ACPI_PROCFS_POWER
 819         result = acpi_battery_add_fs(device);
 820         if (result)
 821                 goto end;
 822 #endif
 823         status = acpi_install_notify_handler(device->handle,
 824                                              ACPI_ALL_NOTIFY,
 825                                              acpi_battery_notify, battery);
 826         if (ACPI_FAILURE(status)) {
 827                 ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
 828                 result = -ENODEV;
 829                 goto end;
 830         }
 831         printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
 832                ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
 833                device->status.battery_present ? "present" : "absent");
 834       end:
 835         if (result) {
 836 #ifdef CONFIG_ACPI_PROCFS_POWER
 837                 acpi_battery_remove_fs(device);
 838 #endif
 839                 kfree(battery);
 840         }
 841         return result;
 842 }
 843
 844 static int acpi_battery_remove(struct acpi_device *device, int type)
 845 {
 846         acpi_status status = 0;
 847         struct acpi_battery *battery = NULL;
 848
 849         if (!device || !acpi_driver_data(device))
 850                 return -EINVAL;
 851         battery = acpi_driver_data(device);
 852         status = acpi_remove_notify_handler(device->handle,
 853                                             ACPI_ALL_NOTIFY,
 854                                             acpi_battery_notify);
 855 #ifdef CONFIG_ACPI_PROCFS_POWER
 856         acpi_battery_remove_fs(device);
 857 #endif
 858 #ifdef CONFIG_ACPI_SYSFS_POWER
 859         sysfs_remove_battery(battery);
 860 #endif
 861         mutex_destroy(&battery->lock);
 862         kfree(battery);
 863         return 0;
 864 }
 865
 866 /* this is needed to learn about changes made in suspended state */
 867 static int acpi_battery_resume(struct acpi_device *device)
 868 {
 869         struct acpi_battery *battery;
 870         if (!device)
 871                 return -EINVAL;
 872         battery = acpi_driver_data(device);
 873         battery->update_time = 0;
 874         acpi_battery_update(battery);
 875         return 0;
 876 }
 877
 878 static struct acpi_driver acpi_battery_driver = {
 879         .name = "battery",
 880         .class = ACPI_BATTERY_CLASS,
 881         .ids = battery_device_ids,
 882         .ops = {
 883                 .add = acpi_battery_add,
 884                 .resume = acpi_battery_resume,
 885                 .remove = acpi_battery_remove,
 886                 },
 887 };
 888
 889 static int __init acpi_battery_init(void)
 890 {
 891         if (acpi_disabled)
 892                 return -ENODEV;
 893 #ifdef CONFIG_ACPI_PROCFS_POWER
 894         acpi_battery_dir = acpi_lock_battery_dir();
 895         if (!acpi_battery_dir)
 896                 return -ENODEV;
 897 #endif
 898         if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
 899 #ifdef CONFIG_ACPI_PROCFS_POWER
 900                 acpi_unlock_battery_dir(acpi_battery_dir);
 901 #endif
 902                 return -ENODEV;
 903         }
 904         return 0;
 905 }
 906
 907 static void __exit acpi_battery_exit(void)
 908 {
 909         acpi_bus_unregister_driver(&acpi_battery_driver);
 910 #ifdef CONFIG_ACPI_PROCFS_POWER
 911         acpi_unlock_battery_dir(acpi_battery_dir);
 912 #endif
 913 }
 914
 915 module_init(acpi_battery_init);
 916 module_exit(acpi_battery_exit);