drivers/acpi/battery.c

   1 /*
   2  *  acpi_battery.c - ACPI Battery Driver ($Revision: 37 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/proc_fs.h>
  31 #include <linux/seq_file.h>
  32 #include <asm/uaccess.h>
  33
  34 #include <acpi/acpi_bus.h>
  35 #include <acpi/acpi_drivers.h>
  36
  37 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
  38
  39 #define ACPI_BATTERY_FORMAT_BIF "NNNNNNNNNSSSS"
  40 #define ACPI_BATTERY_FORMAT_BST "NNNN"
  41
  42 #define ACPI_BATTERY_COMPONENT          0x00040000
  43 #define ACPI_BATTERY_CLASS              "battery"
  44 #define ACPI_BATTERY_HID                "PNP0C0A"
  45 #define ACPI_BATTERY_DRIVER_NAME        "ACPI Battery Driver"
  46 #define ACPI_BATTERY_DEVICE_NAME        "Battery"
  47 #define ACPI_BATTERY_FILE_INFO          "info"
  48 #define ACPI_BATTERY_FILE_STATUS        "state"
  49 #define ACPI_BATTERY_FILE_ALARM         "alarm"
  50 #define ACPI_BATTERY_NOTIFY_STATUS      0x80
  51 #define ACPI_BATTERY_NOTIFY_INFO        0x81
  52 #define ACPI_BATTERY_UNITS_WATTS        "mW"
  53 #define ACPI_BATTERY_UNITS_AMPS         "mA"
  54
  55 #define _COMPONENT              ACPI_BATTERY_COMPONENT
  56 ACPI_MODULE_NAME("acpi_battery")
  57
  58     MODULE_AUTHOR("Paul Diefenbaugh");
  59 MODULE_DESCRIPTION(ACPI_BATTERY_DRIVER_NAME);
  60 MODULE_LICENSE("GPL");
  61
  62 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
  63 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
  64
  65 static int acpi_battery_add(struct acpi_device *device);
  66 static int acpi_battery_remove(struct acpi_device *device, int type);
  67 static int acpi_battery_resume(struct acpi_device *device, int status);
  68
  69 static struct acpi_driver acpi_battery_driver = {
  70         .name = ACPI_BATTERY_DRIVER_NAME,
  71         .class = ACPI_BATTERY_CLASS,
  72         .ids = ACPI_BATTERY_HID,
  73         .ops = {
  74                 .add = acpi_battery_add,
  75                 .resume = acpi_battery_resume,
  76                 .remove = acpi_battery_remove,
  77                 },
  78 };
  79
  80 struct acpi_battery_status {
  81         acpi_integer state;
  82         acpi_integer present_rate;
  83         acpi_integer remaining_capacity;
  84         acpi_integer present_voltage;
  85 };
  86
  87 struct acpi_battery_info {
  88         acpi_integer power_unit;
  89         acpi_integer design_capacity;
  90         acpi_integer last_full_capacity;
  91         acpi_integer battery_technology;
  92         acpi_integer design_voltage;
  93         acpi_integer design_capacity_warning;
  94         acpi_integer design_capacity_low;
  95         acpi_integer battery_capacity_granularity_1;
  96         acpi_integer battery_capacity_granularity_2;
  97         acpi_string model_number;
  98         acpi_string serial_number;
  99         acpi_string battery_type;
 100         acpi_string oem_info;
 101 };
 102
 103 struct acpi_battery_flags {
 104         u8 present:1;           /* Bay occupied? */
 105         u8 power_unit:1;        /* 0=watts, 1=apms */
 106         u8 alarm:1;             /* _BTP present? */
 107         u8 reserved:5;
 108 };
 109
 110 struct acpi_battery_trips {
 111         unsigned long warning;
 112         unsigned long low;
 113 };
 114
 115 struct acpi_battery {
 116         struct acpi_device * device;
 117         struct acpi_battery_flags flags;
 118         struct acpi_battery_trips trips;
 119         unsigned long alarm;
 120         struct acpi_battery_info *info;
 121 };
 122
 123 /* --------------------------------------------------------------------------
 124                                Battery Management
 125    -------------------------------------------------------------------------- */
 126
 127 static int
 128 acpi_battery_get_info(struct acpi_battery *battery,
 129                       struct acpi_battery_info **bif)
 130 {
 131         int result = 0;
 132         acpi_status status = 0;
 133         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 134         struct acpi_buffer format = { sizeof(ACPI_BATTERY_FORMAT_BIF),
 135                 ACPI_BATTERY_FORMAT_BIF
 136         };
 137         struct acpi_buffer data = { 0, NULL };
 138         union acpi_object *package = NULL;
 139
 140
 141         if (!battery || !bif)
 142                 return -EINVAL;
 143
 144         /* Evalute _BIF */
 145
 146         status = acpi_evaluate_object(battery->device->handle, "_BIF", NULL, &buffer);
 147         if (ACPI_FAILURE(status)) {
 148                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
 149                 return -ENODEV;
 150         }
 151
 152         package = (union acpi_object *)buffer.pointer;
 153
 154         /* Extract Package Data */
 155
 156         status = acpi_extract_package(package, &format, &data);
 157         if (status != AE_BUFFER_OVERFLOW) {
 158                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BIF"));
 159                 result = -ENODEV;
 160                 goto end;
 161         }
 162
 163         data.pointer = kmalloc(data.length, GFP_KERNEL);
 164         if (!data.pointer) {
 165                 result = -ENOMEM;
 166                 goto end;
 167         }
 168         memset(data.pointer, 0, data.length);
 169
 170         status = acpi_extract_package(package, &format, &data);
 171         if (ACPI_FAILURE(status)) {
 172                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BIF"));
 173                 kfree(data.pointer);
 174                 result = -ENODEV;
 175                 goto end;
 176         }
 177
 178       end:
 179         kfree(buffer.pointer);
 180
 181         if (!result)
 182                 (*bif) = (struct acpi_battery_info *)data.pointer;
 183
 184         return result;
 185 }
 186
 187 static int
 188 acpi_battery_get_status(struct acpi_battery *battery,
 189                         struct acpi_battery_status **bst)
 190 {
 191         int result = 0;
 192         acpi_status status = 0;
 193         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 194         struct acpi_buffer format = { sizeof(ACPI_BATTERY_FORMAT_BST),
 195                 ACPI_BATTERY_FORMAT_BST
 196         };
 197         struct acpi_buffer data = { 0, NULL };
 198         union acpi_object *package = NULL;
 199
 200
 201         if (!battery || !bst)
 202                 return -EINVAL;
 203
 204         /* Evalute _BST */
 205
 206         status = acpi_evaluate_object(battery->device->handle, "_BST", NULL, &buffer);
 207         if (ACPI_FAILURE(status)) {
 208                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
 209                 return -ENODEV;
 210         }
 211
 212         package = (union acpi_object *)buffer.pointer;
 213
 214         /* Extract Package Data */
 215
 216         status = acpi_extract_package(package, &format, &data);
 217         if (status != AE_BUFFER_OVERFLOW) {
 218                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
 219                 result = -ENODEV;
 220                 goto end;
 221         }
 222
 223         data.pointer = kmalloc(data.length, GFP_KERNEL);
 224         if (!data.pointer) {
 225                 result = -ENOMEM;
 226                 goto end;
 227         }
 228         memset(data.pointer, 0, data.length);
 229
 230         status = acpi_extract_package(package, &format, &data);
 231         if (ACPI_FAILURE(status)) {
 232                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
 233                 kfree(data.pointer);
 234                 result = -ENODEV;
 235                 goto end;
 236         }
 237
 238       end:
 239         kfree(buffer.pointer);
 240
 241         if (!result)
 242                 (*bst) = (struct acpi_battery_status *)data.pointer;
 243
 244         return result;
 245 }
 246
 247 static int
 248 acpi_battery_set_alarm(struct acpi_battery *battery, unsigned long alarm)
 249 {
 250         acpi_status status = 0;
 251         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 252         struct acpi_object_list arg_list = { 1, &arg0 };
 253
 254
 255         if (!battery)
 256                 return -EINVAL;
 257
 258         if (!battery->flags.alarm)
 259                 return -ENODEV;
 260
 261         arg0.integer.value = alarm;
 262
 263         status = acpi_evaluate_object(battery->device->handle, "_BTP", &arg_list, NULL);
 264         if (ACPI_FAILURE(status))
 265                 return -ENODEV;
 266
 267         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", (u32) alarm));
 268
 269         battery->alarm = alarm;
 270
 271         return 0;
 272 }
 273
 274 static int acpi_battery_check(struct acpi_battery *battery)
 275 {
 276         int result = 0;
 277         acpi_status status = AE_OK;
 278         acpi_handle handle = NULL;
 279         struct acpi_device *device = NULL;
 280         struct acpi_battery_info *bif = NULL;
 281
 282
 283         if (!battery)
 284                 return -EINVAL;
 285
 286         device = battery->device;
 287
 288         result = acpi_bus_get_status(device);
 289         if (result)
 290                 return result;
 291
 292         /* Insertion? */
 293
 294         if (!battery->flags.present && device->status.battery_present) {
 295
 296                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery inserted\n"));
 297
 298                 /* Evalute _BIF to get certain static information */
 299
 300                 result = acpi_battery_get_info(battery, &bif);
 301                 if (result)
 302                         return result;
 303
 304                 battery->flags.power_unit = bif->power_unit;
 305                 battery->trips.warning = bif->design_capacity_warning;
 306                 battery->trips.low = bif->design_capacity_low;
 307                 kfree(bif);
 308
 309                 /* See if alarms are supported, and if so, set default */
 310
 311                 status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
 312                 if (ACPI_SUCCESS(status)) {
 313                         battery->flags.alarm = 1;
 314                         acpi_battery_set_alarm(battery, battery->trips.warning);
 315                 }
 316         }
 317
 318         /* Removal? */
 319
 320         else if (battery->flags.present && !device->status.battery_present) {
 321                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery removed\n"));
 322         }
 323
 324         battery->flags.present = device->status.battery_present;
 325
 326         return result;
 327 }
 328
 329 /* --------------------------------------------------------------------------
 330                               FS Interface (/proc)
 331    -------------------------------------------------------------------------- */
 332
 333 static struct proc_dir_entry *acpi_battery_dir;
 334 static int acpi_battery_read_info(struct seq_file *seq, void *offset)
 335 {
 336         int result = 0;
 337         struct acpi_battery *battery = (struct acpi_battery *)seq->private;
 338         struct acpi_battery_info *bif = NULL;
 339         char *units = "?";
 340
 341
 342         if (!battery)
 343                 goto end;
 344
 345         if (battery->flags.present)
 346                 seq_printf(seq, "present:                 yes\n");
 347         else {
 348                 seq_printf(seq, "present:                 no\n");
 349                 goto end;
 350         }
 351
 352         /* Battery Info (_BIF) */
 353
 354         result = acpi_battery_get_info(battery, &bif);
 355         if (result || !bif) {
 356                 seq_printf(seq, "ERROR: Unable to read battery information\n");
 357                 goto end;
 358         }
 359
 360         units =
 361             bif->
 362             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
 363
 364         if (bif->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 365                 seq_printf(seq, "design capacity:         unknown\n");
 366         else
 367                 seq_printf(seq, "design capacity:         %d %sh\n",
 368                            (u32) bif->design_capacity, units);
 369
 370         if (bif->last_full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 371                 seq_printf(seq, "last full capacity:      unknown\n");
 372         else
 373                 seq_printf(seq, "last full capacity:      %d %sh\n",
 374                            (u32) bif->last_full_capacity, units);
 375
 376         switch ((u32) bif->battery_technology) {
 377         case 0:
 378                 seq_printf(seq, "battery technology:      non-rechargeable\n");
 379                 break;
 380         case 1:
 381                 seq_printf(seq, "battery technology:      rechargeable\n");
 382                 break;
 383         default:
 384                 seq_printf(seq, "battery technology:      unknown\n");
 385                 break;
 386         }
 387
 388         if (bif->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 389                 seq_printf(seq, "design voltage:          unknown\n");
 390         else
 391                 seq_printf(seq, "design voltage:          %d mV\n",
 392                            (u32) bif->design_voltage);
 393
 394         seq_printf(seq, "design capacity warning: %d %sh\n",
 395                    (u32) bif->design_capacity_warning, units);
 396         seq_printf(seq, "design capacity low:     %d %sh\n",
 397                    (u32) bif->design_capacity_low, units);
 398         seq_printf(seq, "capacity granularity 1:  %d %sh\n",
 399                    (u32) bif->battery_capacity_granularity_1, units);
 400         seq_printf(seq, "capacity granularity 2:  %d %sh\n",
 401                    (u32) bif->battery_capacity_granularity_2, units);
 402         seq_printf(seq, "model number:            %s\n", bif->model_number);
 403         seq_printf(seq, "serial number:           %s\n", bif->serial_number);
 404         seq_printf(seq, "battery type:            %s\n", bif->battery_type);
 405         seq_printf(seq, "OEM info:                %s\n", bif->oem_info);
 406
 407       end:
 408         kfree(bif);
 409
 410         return 0;
 411 }
 412
 413 static int acpi_battery_info_open_fs(struct inode *inode, struct file *file)
 414 {
 415         return single_open(file, acpi_battery_read_info, PDE(inode)->data);
 416 }
 417
 418 static int acpi_battery_read_state(struct seq_file *seq, void *offset)
 419 {
 420         int result = 0;
 421         struct acpi_battery *battery = (struct acpi_battery *)seq->private;
 422         struct acpi_battery_status *bst = NULL;
 423         char *units = "?";
 424
 425
 426         if (!battery)
 427                 goto end;
 428
 429         if (battery->flags.present)
 430                 seq_printf(seq, "present:                 yes\n");
 431         else {
 432                 seq_printf(seq, "present:                 no\n");
 433                 goto end;
 434         }
 435
 436         /* Battery Units */
 437
 438         units =
 439             battery->flags.
 440             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
 441
 442         /* Battery Status (_BST) */
 443
 444         result = acpi_battery_get_status(battery, &bst);
 445         if (result || !bst) {
 446                 seq_printf(seq, "ERROR: Unable to read battery status\n");
 447                 goto end;
 448         }
 449
 450         if (!(bst->state & 0x04))
 451                 seq_printf(seq, "capacity state:          ok\n");
 452         else
 453                 seq_printf(seq, "capacity state:          critical\n");
 454
 455         if ((bst->state & 0x01) && (bst->state & 0x02)) {
 456                 seq_printf(seq,
 457                            "charging state:          charging/discharging\n");
 458         } else if (bst->state & 0x01)
 459                 seq_printf(seq, "charging state:          discharging\n");
 460         else if (bst->state & 0x02)
 461                 seq_printf(seq, "charging state:          charging\n");
 462         else {
 463                 seq_printf(seq, "charging state:          charged\n");
 464         }
 465
 466         if (bst->present_rate == ACPI_BATTERY_VALUE_UNKNOWN)
 467                 seq_printf(seq, "present rate:            unknown\n");
 468         else
 469                 seq_printf(seq, "present rate:            %d %s\n",
 470                            (u32) bst->present_rate, units);
 471
 472         if (bst->remaining_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
 473                 seq_printf(seq, "remaining capacity:      unknown\n");
 474         else
 475                 seq_printf(seq, "remaining capacity:      %d %sh\n",
 476                            (u32) bst->remaining_capacity, units);
 477
 478         if (bst->present_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
 479                 seq_printf(seq, "present voltage:         unknown\n");
 480         else
 481                 seq_printf(seq, "present voltage:         %d mV\n",
 482                            (u32) bst->present_voltage);
 483
 484       end:
 485         kfree(bst);
 486
 487         return 0;
 488 }
 489
 490 static int acpi_battery_state_open_fs(struct inode *inode, struct file *file)
 491 {
 492         return single_open(file, acpi_battery_read_state, PDE(inode)->data);
 493 }
 494
 495 static int acpi_battery_read_alarm(struct seq_file *seq, void *offset)
 496 {
 497         struct acpi_battery *battery = (struct acpi_battery *)seq->private;
 498         char *units = "?";
 499
 500
 501         if (!battery)
 502                 goto end;
 503
 504         if (!battery->flags.present) {
 505                 seq_printf(seq, "present:                 no\n");
 506                 goto end;
 507         }
 508
 509         /* Battery Units */
 510
 511         units =
 512             battery->flags.
 513             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
 514
 515         /* Battery Alarm */
 516
 517         seq_printf(seq, "alarm:                   ");
 518         if (!battery->alarm)
 519                 seq_printf(seq, "unsupported\n");
 520         else
 521                 seq_printf(seq, "%d %sh\n", (u32) battery->alarm, units);
 522
 523       end:
 524         return 0;
 525 }
 526
 527 static ssize_t
 528 acpi_battery_write_alarm(struct file *file,
 529                          const char __user * buffer,
 530                          size_t count, loff_t * ppos)
 531 {
 532         int result = 0;
 533         char alarm_string[12] = { '\0' };
 534         struct seq_file *m = (struct seq_file *)file->private_data;
 535         struct acpi_battery *battery = (struct acpi_battery *)m->private;
 536
 537
 538         if (!battery || (count > sizeof(alarm_string) - 1))
 539                 return -EINVAL;
 540
 541         if (!battery->flags.present)
 542                 return -ENODEV;
 543
 544         if (copy_from_user(alarm_string, buffer, count))
 545                 return -EFAULT;
 546
 547         alarm_string[count] = '\0';
 548
 549         result = acpi_battery_set_alarm(battery,
 550                                         simple_strtoul(alarm_string, NULL, 0));
 551         if (result)
 552                 return result;
 553
 554         return count;
 555 }
 556
 557 static int acpi_battery_alarm_open_fs(struct inode *inode, struct file *file)
 558 {
 559         return single_open(file, acpi_battery_read_alarm, PDE(inode)->data);
 560 }
 561
 562 static const struct file_operations acpi_battery_info_ops = {
 563         .open = acpi_battery_info_open_fs,
 564         .read = seq_read,
 565         .llseek = seq_lseek,
 566         .release = single_release,
 567         .owner = THIS_MODULE,
 568 };
 569
 570 static const struct file_operations acpi_battery_state_ops = {
 571         .open = acpi_battery_state_open_fs,
 572         .read = seq_read,
 573         .llseek = seq_lseek,
 574         .release = single_release,
 575         .owner = THIS_MODULE,
 576 };
 577
 578 static const struct file_operations acpi_battery_alarm_ops = {
 579         .open = acpi_battery_alarm_open_fs,
 580         .read = seq_read,
 581         .write = acpi_battery_write_alarm,
 582         .llseek = seq_lseek,
 583         .release = single_release,
 584         .owner = THIS_MODULE,
 585 };
 586
 587 static int acpi_battery_add_fs(struct acpi_device *device)
 588 {
 589         struct proc_dir_entry *entry = NULL;
 590
 591
 592         if (!acpi_device_dir(device)) {
 593                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 594                                                      acpi_battery_dir);
 595                 if (!acpi_device_dir(device))
 596                         return -ENODEV;
 597                 acpi_device_dir(device)->owner = THIS_MODULE;
 598         }
 599
 600         /* 'info' [R] */
 601         entry = create_proc_entry(ACPI_BATTERY_FILE_INFO,
 602                                   S_IRUGO, acpi_device_dir(device));
 603         if (!entry)
 604                 return -ENODEV;
 605         else {
 606                 entry->proc_fops = &acpi_battery_info_ops;
 607                 entry->data = acpi_driver_data(device);
 608                 entry->owner = THIS_MODULE;
 609         }
 610
 611         /* 'status' [R] */
 612         entry = create_proc_entry(ACPI_BATTERY_FILE_STATUS,
 613                                   S_IRUGO, acpi_device_dir(device));
 614         if (!entry)
 615                 return -ENODEV;
 616         else {
 617                 entry->proc_fops = &acpi_battery_state_ops;
 618                 entry->data = acpi_driver_data(device);
 619                 entry->owner = THIS_MODULE;
 620         }
 621
 622         /* 'alarm' [R/W] */
 623         entry = create_proc_entry(ACPI_BATTERY_FILE_ALARM,
 624                                   S_IFREG | S_IRUGO | S_IWUSR,
 625                                   acpi_device_dir(device));
 626         if (!entry)
 627                 return -ENODEV;
 628         else {
 629                 entry->proc_fops = &acpi_battery_alarm_ops;
 630                 entry->data = acpi_driver_data(device);
 631                 entry->owner = THIS_MODULE;
 632         }
 633
 634         return 0;
 635 }
 636
 637 static int acpi_battery_remove_fs(struct acpi_device *device)
 638 {
 639
 640         if (acpi_device_dir(device)) {
 641                 remove_proc_entry(ACPI_BATTERY_FILE_ALARM,
 642                                   acpi_device_dir(device));
 643                 remove_proc_entry(ACPI_BATTERY_FILE_STATUS,
 644                                   acpi_device_dir(device));
 645                 remove_proc_entry(ACPI_BATTERY_FILE_INFO,
 646                                   acpi_device_dir(device));
 647
 648                 remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
 649                 acpi_device_dir(device) = NULL;
 650         }
 651
 652         return 0;
 653 }
 654
 655 /* --------------------------------------------------------------------------
 656                                  Driver Interface
 657    -------------------------------------------------------------------------- */
 658
 659 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
 660 {
 661         struct acpi_battery *battery = (struct acpi_battery *)data;
 662         struct acpi_device *device = NULL;
 663
 664
 665         if (!battery)
 666                 return;
 667
 668         device = battery->device;
 669
 670         switch (event) {
 671         case ACPI_BATTERY_NOTIFY_STATUS:
 672         case ACPI_BATTERY_NOTIFY_INFO:
 673         case ACPI_NOTIFY_BUS_CHECK:
 674         case ACPI_NOTIFY_DEVICE_CHECK:
 675                 acpi_battery_check(battery);
 676                 acpi_bus_generate_event(device, event, battery->flags.present);
 677                 break;
 678         default:
 679                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 680                                   "Unsupported event [0x%x]\n", event));
 681                 break;
 682         }
 683
 684         return;
 685 }
 686
 687 static int acpi_battery_add(struct acpi_device *device)
 688 {
 689         int result = 0;
 690         acpi_status status = 0;
 691         struct acpi_battery *battery = NULL;
 692
 693
 694         if (!device)
 695                 return -EINVAL;
 696
 697         battery = kmalloc(sizeof(struct acpi_battery), GFP_KERNEL);
 698         if (!battery)
 699                 return -ENOMEM;
 700         memset(battery, 0, sizeof(struct acpi_battery));
 701
 702         battery->device = device;
 703         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
 704         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
 705         acpi_driver_data(device) = battery;
 706
 707         result = acpi_battery_check(battery);
 708         if (result)
 709                 goto end;
 710
 711         result = acpi_battery_add_fs(device);
 712         if (result)
 713                 goto end;
 714
 715         status = acpi_install_notify_handler(device->handle,
 716                                              ACPI_ALL_NOTIFY,
 717                                              acpi_battery_notify, battery);
 718         if (ACPI_FAILURE(status)) {
 719                 result = -ENODEV;
 720                 goto end;
 721         }
 722
 723         printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
 724                ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
 725                device->status.battery_present ? "present" : "absent");
 726
 727       end:
 728         if (result) {
 729                 acpi_battery_remove_fs(device);
 730                 kfree(battery);
 731         }
 732
 733         return result;
 734 }
 735
 736 static int acpi_battery_remove(struct acpi_device *device, int type)
 737 {
 738         acpi_status status = 0;
 739         struct acpi_battery *battery = NULL;
 740
 741
 742         if (!device || !acpi_driver_data(device))
 743                 return -EINVAL;
 744
 745         battery = (struct acpi_battery *)acpi_driver_data(device);
 746
 747         status = acpi_remove_notify_handler(device->handle,
 748                                             ACPI_ALL_NOTIFY,
 749                                             acpi_battery_notify);
 750
 751         acpi_battery_remove_fs(device);
 752
 753         kfree(battery);
 754
 755         return 0;
 756 }
 757
 758 /* this is needed to learn about changes made in suspended state */
 759 static int acpi_battery_resume(struct acpi_device *device, int state)
 760 {
 761         struct acpi_battery *battery;
 762
 763         if (!device)
 764                 return -EINVAL;
 765
 766         battery = device->driver_data;
 767         return acpi_battery_check(battery);
 768 }
 769
 770 static int __init acpi_battery_init(void)
 771 {
 772         int result;
 773
 774         if (acpi_disabled)
 775                 return -ENODEV;
 776
 777         acpi_battery_dir = acpi_lock_battery_dir();
 778         if (!acpi_battery_dir)
 779                 return -ENODEV;
 780
 781         result = acpi_bus_register_driver(&acpi_battery_driver);
 782         if (result < 0) {
 783                 acpi_unlock_battery_dir(acpi_battery_dir);
 784                 return -ENODEV;
 785         }
 786
 787         return 0;
 788 }
 789
 790 static void __exit acpi_battery_exit(void)
 791 {
 792
 793         acpi_bus_unregister_driver(&acpi_battery_driver);
 794
 795         acpi_unlock_battery_dir(acpi_battery_dir);
 796
 797         return;
 798 }
 799
 800 module_init(acpi_battery_init);
 801 module_exit(acpi_battery_exit);