ACPI: battery: check for battery present on /proc/battery access
[linux-3.10.git] / 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);
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 = 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 = kzalloc(data.length, GFP_KERNEL);
164         if (!data.pointer) {
165                 result = -ENOMEM;
166                 goto end;
167         }
168
169         status = acpi_extract_package(package, &format, &data);
170         if (ACPI_FAILURE(status)) {
171                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BIF"));
172                 kfree(data.pointer);
173                 result = -ENODEV;
174                 goto end;
175         }
176
177       end:
178         kfree(buffer.pointer);
179
180         if (!result)
181                 (*bif) = data.pointer;
182
183         return result;
184 }
185
186 static int
187 acpi_battery_get_status(struct acpi_battery *battery,
188                         struct acpi_battery_status **bst)
189 {
190         int result = 0;
191         acpi_status status = 0;
192         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
193         struct acpi_buffer format = { sizeof(ACPI_BATTERY_FORMAT_BST),
194                 ACPI_BATTERY_FORMAT_BST
195         };
196         struct acpi_buffer data = { 0, NULL };
197         union acpi_object *package = NULL;
198
199
200         if (!battery || !bst)
201                 return -EINVAL;
202
203         /* Evalute _BST */
204
205         status = acpi_evaluate_object(battery->device->handle, "_BST", NULL, &buffer);
206         if (ACPI_FAILURE(status)) {
207                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
208                 return -ENODEV;
209         }
210
211         package = buffer.pointer;
212
213         /* Extract Package Data */
214
215         status = acpi_extract_package(package, &format, &data);
216         if (status != AE_BUFFER_OVERFLOW) {
217                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
218                 result = -ENODEV;
219                 goto end;
220         }
221
222         data.pointer = kzalloc(data.length, GFP_KERNEL);
223         if (!data.pointer) {
224                 result = -ENOMEM;
225                 goto end;
226         }
227
228         status = acpi_extract_package(package, &format, &data);
229         if (ACPI_FAILURE(status)) {
230                 ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
231                 kfree(data.pointer);
232                 result = -ENODEV;
233                 goto end;
234         }
235
236       end:
237         kfree(buffer.pointer);
238
239         if (!result)
240                 (*bst) = data.pointer;
241
242         return result;
243 }
244
245 static int
246 acpi_battery_set_alarm(struct acpi_battery *battery, unsigned long alarm)
247 {
248         acpi_status status = 0;
249         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
250         struct acpi_object_list arg_list = { 1, &arg0 };
251
252
253         if (!battery)
254                 return -EINVAL;
255
256         if (!battery->flags.alarm)
257                 return -ENODEV;
258
259         arg0.integer.value = alarm;
260
261         status = acpi_evaluate_object(battery->device->handle, "_BTP", &arg_list, NULL);
262         if (ACPI_FAILURE(status))
263                 return -ENODEV;
264
265         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", (u32) alarm));
266
267         battery->alarm = alarm;
268
269         return 0;
270 }
271
272 static int acpi_battery_check(struct acpi_battery *battery)
273 {
274         int result = 0;
275         acpi_status status = AE_OK;
276         acpi_handle handle = NULL;
277         struct acpi_device *device = NULL;
278         struct acpi_battery_info *bif = NULL;
279
280
281         if (!battery)
282                 return -EINVAL;
283
284         device = battery->device;
285
286         result = acpi_bus_get_status(device);
287         if (result)
288                 return result;
289
290         /* Insertion? */
291
292         if (!battery->flags.present && device->status.battery_present) {
293
294                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery inserted\n"));
295
296                 /* Evalute _BIF to get certain static information */
297
298                 result = acpi_battery_get_info(battery, &bif);
299                 if (result)
300                         return result;
301
302                 battery->flags.power_unit = bif->power_unit;
303                 battery->trips.warning = bif->design_capacity_warning;
304                 battery->trips.low = bif->design_capacity_low;
305                 kfree(bif);
306
307                 /* See if alarms are supported, and if so, set default */
308
309                 status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
310                 if (ACPI_SUCCESS(status)) {
311                         battery->flags.alarm = 1;
312                         acpi_battery_set_alarm(battery, battery->trips.warning);
313                 }
314         }
315
316         /* Removal? */
317
318         else if (battery->flags.present && !device->status.battery_present) {
319                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery removed\n"));
320         }
321
322         battery->flags.present = device->status.battery_present;
323
324         return result;
325 }
326
327 static void acpi_battery_check_present(struct acpi_battery *battery)
328 {
329         if (!battery->flags.present) {
330                 acpi_battery_check(battery);
331         }
332 }
333
334 /* --------------------------------------------------------------------------
335                               FS Interface (/proc)
336    -------------------------------------------------------------------------- */
337
338 static struct proc_dir_entry *acpi_battery_dir;
339 static int acpi_battery_read_info(struct seq_file *seq, void *offset)
340 {
341         int result = 0;
342         struct acpi_battery *battery = seq->private;
343         struct acpi_battery_info *bif = NULL;
344         char *units = "?";
345
346
347         if (!battery)
348                 goto end;
349
350         acpi_battery_check_present(battery);
351
352         if (battery->flags.present)
353                 seq_printf(seq, "present:                 yes\n");
354         else {
355                 seq_printf(seq, "present:                 no\n");
356                 goto end;
357         }
358
359         /* Battery Info (_BIF) */
360
361         result = acpi_battery_get_info(battery, &bif);
362         if (result || !bif) {
363                 seq_printf(seq, "ERROR: Unable to read battery information\n");
364                 goto end;
365         }
366
367         units =
368             bif->
369             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
370
371         if (bif->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
372                 seq_printf(seq, "design capacity:         unknown\n");
373         else
374                 seq_printf(seq, "design capacity:         %d %sh\n",
375                            (u32) bif->design_capacity, units);
376
377         if (bif->last_full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
378                 seq_printf(seq, "last full capacity:      unknown\n");
379         else
380                 seq_printf(seq, "last full capacity:      %d %sh\n",
381                            (u32) bif->last_full_capacity, units);
382
383         switch ((u32) bif->battery_technology) {
384         case 0:
385                 seq_printf(seq, "battery technology:      non-rechargeable\n");
386                 break;
387         case 1:
388                 seq_printf(seq, "battery technology:      rechargeable\n");
389                 break;
390         default:
391                 seq_printf(seq, "battery technology:      unknown\n");
392                 break;
393         }
394
395         if (bif->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
396                 seq_printf(seq, "design voltage:          unknown\n");
397         else
398                 seq_printf(seq, "design voltage:          %d mV\n",
399                            (u32) bif->design_voltage);
400
401         seq_printf(seq, "design capacity warning: %d %sh\n",
402                    (u32) bif->design_capacity_warning, units);
403         seq_printf(seq, "design capacity low:     %d %sh\n",
404                    (u32) bif->design_capacity_low, units);
405         seq_printf(seq, "capacity granularity 1:  %d %sh\n",
406                    (u32) bif->battery_capacity_granularity_1, units);
407         seq_printf(seq, "capacity granularity 2:  %d %sh\n",
408                    (u32) bif->battery_capacity_granularity_2, units);
409         seq_printf(seq, "model number:            %s\n", bif->model_number);
410         seq_printf(seq, "serial number:           %s\n", bif->serial_number);
411         seq_printf(seq, "battery type:            %s\n", bif->battery_type);
412         seq_printf(seq, "OEM info:                %s\n", bif->oem_info);
413
414       end:
415         kfree(bif);
416
417         return 0;
418 }
419
420 static int acpi_battery_info_open_fs(struct inode *inode, struct file *file)
421 {
422         return single_open(file, acpi_battery_read_info, PDE(inode)->data);
423 }
424
425 static int acpi_battery_read_state(struct seq_file *seq, void *offset)
426 {
427         int result = 0;
428         struct acpi_battery *battery = seq->private;
429         struct acpi_battery_status *bst = NULL;
430         char *units = "?";
431
432
433         if (!battery)
434                 goto end;
435
436         acpi_battery_check_present(battery);
437
438         if (battery->flags.present)
439                 seq_printf(seq, "present:                 yes\n");
440         else {
441                 seq_printf(seq, "present:                 no\n");
442                 goto end;
443         }
444
445         /* Battery Units */
446
447         units =
448             battery->flags.
449             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
450
451         /* Battery Status (_BST) */
452
453         result = acpi_battery_get_status(battery, &bst);
454         if (result || !bst) {
455                 seq_printf(seq, "ERROR: Unable to read battery status\n");
456                 goto end;
457         }
458
459         if (!(bst->state & 0x04))
460                 seq_printf(seq, "capacity state:          ok\n");
461         else
462                 seq_printf(seq, "capacity state:          critical\n");
463
464         if ((bst->state & 0x01) && (bst->state & 0x02)) {
465                 seq_printf(seq,
466                            "charging state:          charging/discharging\n");
467         } else if (bst->state & 0x01)
468                 seq_printf(seq, "charging state:          discharging\n");
469         else if (bst->state & 0x02)
470                 seq_printf(seq, "charging state:          charging\n");
471         else {
472                 seq_printf(seq, "charging state:          charged\n");
473         }
474
475         if (bst->present_rate == ACPI_BATTERY_VALUE_UNKNOWN)
476                 seq_printf(seq, "present rate:            unknown\n");
477         else
478                 seq_printf(seq, "present rate:            %d %s\n",
479                            (u32) bst->present_rate, units);
480
481         if (bst->remaining_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
482                 seq_printf(seq, "remaining capacity:      unknown\n");
483         else
484                 seq_printf(seq, "remaining capacity:      %d %sh\n",
485                            (u32) bst->remaining_capacity, units);
486
487         if (bst->present_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
488                 seq_printf(seq, "present voltage:         unknown\n");
489         else
490                 seq_printf(seq, "present voltage:         %d mV\n",
491                            (u32) bst->present_voltage);
492
493       end:
494         kfree(bst);
495
496         return 0;
497 }
498
499 static int acpi_battery_state_open_fs(struct inode *inode, struct file *file)
500 {
501         return single_open(file, acpi_battery_read_state, PDE(inode)->data);
502 }
503
504 static int acpi_battery_read_alarm(struct seq_file *seq, void *offset)
505 {
506         struct acpi_battery *battery = seq->private;
507         char *units = "?";
508
509
510         if (!battery)
511                 goto end;
512
513         acpi_battery_check_present(battery);
514
515         if (!battery->flags.present) {
516                 seq_printf(seq, "present:                 no\n");
517                 goto end;
518         }
519
520         /* Battery Units */
521
522         units =
523             battery->flags.
524             power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
525
526         /* Battery Alarm */
527
528         seq_printf(seq, "alarm:                   ");
529         if (!battery->alarm)
530                 seq_printf(seq, "unsupported\n");
531         else
532                 seq_printf(seq, "%d %sh\n", (u32) battery->alarm, units);
533
534       end:
535         return 0;
536 }
537
538 static ssize_t
539 acpi_battery_write_alarm(struct file *file,
540                          const char __user * buffer,
541                          size_t count, loff_t * ppos)
542 {
543         int result = 0;
544         char alarm_string[12] = { '\0' };
545         struct seq_file *m = file->private_data;
546         struct acpi_battery *battery = m->private;
547
548
549         if (!battery || (count > sizeof(alarm_string) - 1))
550                 return -EINVAL;
551
552         acpi_battery_check_present(battery);
553
554         if (!battery->flags.present)
555                 return -ENODEV;
556
557         if (copy_from_user(alarm_string, buffer, count))
558                 return -EFAULT;
559
560         alarm_string[count] = '\0';
561
562         result = acpi_battery_set_alarm(battery,
563                                         simple_strtoul(alarm_string, NULL, 0));
564         if (result)
565                 return result;
566
567         return count;
568 }
569
570 static int acpi_battery_alarm_open_fs(struct inode *inode, struct file *file)
571 {
572         return single_open(file, acpi_battery_read_alarm, PDE(inode)->data);
573 }
574
575 static const struct file_operations acpi_battery_info_ops = {
576         .open = acpi_battery_info_open_fs,
577         .read = seq_read,
578         .llseek = seq_lseek,
579         .release = single_release,
580         .owner = THIS_MODULE,
581 };
582
583 static const struct file_operations acpi_battery_state_ops = {
584         .open = acpi_battery_state_open_fs,
585         .read = seq_read,
586         .llseek = seq_lseek,
587         .release = single_release,
588         .owner = THIS_MODULE,
589 };
590
591 static const struct file_operations acpi_battery_alarm_ops = {
592         .open = acpi_battery_alarm_open_fs,
593         .read = seq_read,
594         .write = acpi_battery_write_alarm,
595         .llseek = seq_lseek,
596         .release = single_release,
597         .owner = THIS_MODULE,
598 };
599
600 static int acpi_battery_add_fs(struct acpi_device *device)
601 {
602         struct proc_dir_entry *entry = NULL;
603
604
605         if (!acpi_device_dir(device)) {
606                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
607                                                      acpi_battery_dir);
608                 if (!acpi_device_dir(device))
609                         return -ENODEV;
610                 acpi_device_dir(device)->owner = THIS_MODULE;
611         }
612
613         /* 'info' [R] */
614         entry = create_proc_entry(ACPI_BATTERY_FILE_INFO,
615                                   S_IRUGO, acpi_device_dir(device));
616         if (!entry)
617                 return -ENODEV;
618         else {
619                 entry->proc_fops = &acpi_battery_info_ops;
620                 entry->data = acpi_driver_data(device);
621                 entry->owner = THIS_MODULE;
622         }
623
624         /* 'status' [R] */
625         entry = create_proc_entry(ACPI_BATTERY_FILE_STATUS,
626                                   S_IRUGO, acpi_device_dir(device));
627         if (!entry)
628                 return -ENODEV;
629         else {
630                 entry->proc_fops = &acpi_battery_state_ops;
631                 entry->data = acpi_driver_data(device);
632                 entry->owner = THIS_MODULE;
633         }
634
635         /* 'alarm' [R/W] */
636         entry = create_proc_entry(ACPI_BATTERY_FILE_ALARM,
637                                   S_IFREG | S_IRUGO | S_IWUSR,
638                                   acpi_device_dir(device));
639         if (!entry)
640                 return -ENODEV;
641         else {
642                 entry->proc_fops = &acpi_battery_alarm_ops;
643                 entry->data = acpi_driver_data(device);
644                 entry->owner = THIS_MODULE;
645         }
646
647         return 0;
648 }
649
650 static int acpi_battery_remove_fs(struct acpi_device *device)
651 {
652
653         if (acpi_device_dir(device)) {
654                 remove_proc_entry(ACPI_BATTERY_FILE_ALARM,
655                                   acpi_device_dir(device));
656                 remove_proc_entry(ACPI_BATTERY_FILE_STATUS,
657                                   acpi_device_dir(device));
658                 remove_proc_entry(ACPI_BATTERY_FILE_INFO,
659                                   acpi_device_dir(device));
660
661                 remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
662                 acpi_device_dir(device) = NULL;
663         }
664
665         return 0;
666 }
667
668 /* --------------------------------------------------------------------------
669                                  Driver Interface
670    -------------------------------------------------------------------------- */
671
672 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
673 {
674         struct acpi_battery *battery = data;
675         struct acpi_device *device = NULL;
676
677
678         if (!battery)
679                 return;
680
681         device = battery->device;
682
683         switch (event) {
684         case ACPI_BATTERY_NOTIFY_STATUS:
685         case ACPI_BATTERY_NOTIFY_INFO:
686         case ACPI_NOTIFY_BUS_CHECK:
687         case ACPI_NOTIFY_DEVICE_CHECK:
688                 acpi_battery_check(battery);
689                 acpi_bus_generate_event(device, event, battery->flags.present);
690                 break;
691         default:
692                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
693                                   "Unsupported event [0x%x]\n", event));
694                 break;
695         }
696
697         return;
698 }
699
700 static int acpi_battery_add(struct acpi_device *device)
701 {
702         int result = 0;
703         acpi_status status = 0;
704         struct acpi_battery *battery = NULL;
705
706
707         if (!device)
708                 return -EINVAL;
709
710         battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
711         if (!battery)
712                 return -ENOMEM;
713
714         battery->device = device;
715         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
716         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
717         acpi_driver_data(device) = battery;
718
719         result = acpi_battery_check(battery);
720         if (result)
721                 goto end;
722
723         result = acpi_battery_add_fs(device);
724         if (result)
725                 goto end;
726
727         status = acpi_install_notify_handler(device->handle,
728                                              ACPI_ALL_NOTIFY,
729                                              acpi_battery_notify, battery);
730         if (ACPI_FAILURE(status)) {
731                 result = -ENODEV;
732                 goto end;
733         }
734
735         printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
736                ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
737                device->status.battery_present ? "present" : "absent");
738
739       end:
740         if (result) {
741                 acpi_battery_remove_fs(device);
742                 kfree(battery);
743         }
744
745         return result;
746 }
747
748 static int acpi_battery_remove(struct acpi_device *device, int type)
749 {
750         acpi_status status = 0;
751         struct acpi_battery *battery = NULL;
752
753
754         if (!device || !acpi_driver_data(device))
755                 return -EINVAL;
756
757         battery = acpi_driver_data(device);
758
759         status = acpi_remove_notify_handler(device->handle,
760                                             ACPI_ALL_NOTIFY,
761                                             acpi_battery_notify);
762
763         acpi_battery_remove_fs(device);
764
765         kfree(battery);
766
767         return 0;
768 }
769
770 /* this is needed to learn about changes made in suspended state */
771 static int acpi_battery_resume(struct acpi_device *device)
772 {
773         struct acpi_battery *battery;
774
775         if (!device)
776                 return -EINVAL;
777
778         battery = device->driver_data;
779         return acpi_battery_check(battery);
780 }
781
782 static int __init acpi_battery_init(void)
783 {
784         int result;
785
786         if (acpi_disabled)
787                 return -ENODEV;
788
789         acpi_battery_dir = acpi_lock_battery_dir();
790         if (!acpi_battery_dir)
791                 return -ENODEV;
792
793         result = acpi_bus_register_driver(&acpi_battery_driver);
794         if (result < 0) {
795                 acpi_unlock_battery_dir(acpi_battery_dir);
796                 return -ENODEV;
797         }
798
799         return 0;
800 }
801
802 static void __exit acpi_battery_exit(void)
803 {
804
805         acpi_bus_unregister_driver(&acpi_battery_driver);
806
807         acpi_unlock_battery_dir(acpi_battery_dir);
808
809         return;
810 }
811
812 module_init(acpi_battery_init);
813 module_exit(acpi_battery_exit);