xref: /openbmc/linux/drivers/acpi/battery.c (revision 64c70b1c)
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_DEVICE_NAME	"Battery"
46 #define ACPI_BATTERY_FILE_INFO		"info"
47 #define ACPI_BATTERY_FILE_STATUS	"state"
48 #define ACPI_BATTERY_FILE_ALARM		"alarm"
49 #define ACPI_BATTERY_NOTIFY_STATUS	0x80
50 #define ACPI_BATTERY_NOTIFY_INFO	0x81
51 #define ACPI_BATTERY_UNITS_WATTS	"mW"
52 #define ACPI_BATTERY_UNITS_AMPS		"mA"
53 
54 #define _COMPONENT		ACPI_BATTERY_COMPONENT
55 ACPI_MODULE_NAME("battery");
56 
57 MODULE_AUTHOR("Paul Diefenbaugh");
58 MODULE_DESCRIPTION("ACPI Battery Driver");
59 MODULE_LICENSE("GPL");
60 
61 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
62 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
63 
64 static int acpi_battery_add(struct acpi_device *device);
65 static int acpi_battery_remove(struct acpi_device *device, int type);
66 static int acpi_battery_resume(struct acpi_device *device);
67 
68 static struct acpi_driver acpi_battery_driver = {
69 	.name = "battery",
70 	.class = ACPI_BATTERY_CLASS,
71 	.ids = ACPI_BATTERY_HID,
72 	.ops = {
73 		.add = acpi_battery_add,
74 		.resume = acpi_battery_resume,
75 		.remove = acpi_battery_remove,
76 		},
77 };
78 
79 struct acpi_battery_status {
80 	acpi_integer state;
81 	acpi_integer present_rate;
82 	acpi_integer remaining_capacity;
83 	acpi_integer present_voltage;
84 };
85 
86 struct acpi_battery_info {
87 	acpi_integer power_unit;
88 	acpi_integer design_capacity;
89 	acpi_integer last_full_capacity;
90 	acpi_integer battery_technology;
91 	acpi_integer design_voltage;
92 	acpi_integer design_capacity_warning;
93 	acpi_integer design_capacity_low;
94 	acpi_integer battery_capacity_granularity_1;
95 	acpi_integer battery_capacity_granularity_2;
96 	acpi_string model_number;
97 	acpi_string serial_number;
98 	acpi_string battery_type;
99 	acpi_string oem_info;
100 };
101 
102 struct acpi_battery_flags {
103 	u8 present:1;		/* Bay occupied? */
104 	u8 power_unit:1;	/* 0=watts, 1=apms */
105 	u8 alarm:1;		/* _BTP present? */
106 	u8 reserved:5;
107 };
108 
109 struct acpi_battery_trips {
110 	unsigned long warning;
111 	unsigned long low;
112 };
113 
114 struct acpi_battery {
115 	struct acpi_device * device;
116 	struct acpi_battery_flags flags;
117 	struct acpi_battery_trips trips;
118 	unsigned long alarm;
119 	struct acpi_battery_info *info;
120 };
121 
122 /* --------------------------------------------------------------------------
123                                Battery Management
124    -------------------------------------------------------------------------- */
125 
126 static int
127 acpi_battery_get_info(struct acpi_battery *battery,
128 		      struct acpi_battery_info **bif)
129 {
130 	int result = 0;
131 	acpi_status status = 0;
132 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
133 	struct acpi_buffer format = { sizeof(ACPI_BATTERY_FORMAT_BIF),
134 		ACPI_BATTERY_FORMAT_BIF
135 	};
136 	struct acpi_buffer data = { 0, NULL };
137 	union acpi_object *package = NULL;
138 
139 
140 	if (!battery || !bif)
141 		return -EINVAL;
142 
143 	/* Evalute _BIF */
144 
145 	status = acpi_evaluate_object(battery->device->handle, "_BIF", NULL, &buffer);
146 	if (ACPI_FAILURE(status)) {
147 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
148 		return -ENODEV;
149 	}
150 
151 	package = buffer.pointer;
152 
153 	/* Extract Package Data */
154 
155 	status = acpi_extract_package(package, &format, &data);
156 	if (status != AE_BUFFER_OVERFLOW) {
157 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _BIF"));
158 		result = -ENODEV;
159 		goto end;
160 	}
161 
162 	data.pointer = kzalloc(data.length, GFP_KERNEL);
163 	if (!data.pointer) {
164 		result = -ENOMEM;
165 		goto end;
166 	}
167 
168 	status = acpi_extract_package(package, &format, &data);
169 	if (ACPI_FAILURE(status)) {
170 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _BIF"));
171 		kfree(data.pointer);
172 		result = -ENODEV;
173 		goto end;
174 	}
175 
176       end:
177 	kfree(buffer.pointer);
178 
179 	if (!result)
180 		(*bif) = data.pointer;
181 
182 	return result;
183 }
184 
185 static int
186 acpi_battery_get_status(struct acpi_battery *battery,
187 			struct acpi_battery_status **bst)
188 {
189 	int result = 0;
190 	acpi_status status = 0;
191 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
192 	struct acpi_buffer format = { sizeof(ACPI_BATTERY_FORMAT_BST),
193 		ACPI_BATTERY_FORMAT_BST
194 	};
195 	struct acpi_buffer data = { 0, NULL };
196 	union acpi_object *package = NULL;
197 
198 
199 	if (!battery || !bst)
200 		return -EINVAL;
201 
202 	/* Evalute _BST */
203 
204 	status = acpi_evaluate_object(battery->device->handle, "_BST", NULL, &buffer);
205 	if (ACPI_FAILURE(status)) {
206 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
207 		return -ENODEV;
208 	}
209 
210 	package = buffer.pointer;
211 
212 	/* Extract Package Data */
213 
214 	status = acpi_extract_package(package, &format, &data);
215 	if (status != AE_BUFFER_OVERFLOW) {
216 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
217 		result = -ENODEV;
218 		goto end;
219 	}
220 
221 	data.pointer = kzalloc(data.length, GFP_KERNEL);
222 	if (!data.pointer) {
223 		result = -ENOMEM;
224 		goto end;
225 	}
226 
227 	status = acpi_extract_package(package, &format, &data);
228 	if (ACPI_FAILURE(status)) {
229 		ACPI_EXCEPTION((AE_INFO, status, "Extracting _BST"));
230 		kfree(data.pointer);
231 		result = -ENODEV;
232 		goto end;
233 	}
234 
235       end:
236 	kfree(buffer.pointer);
237 
238 	if (!result)
239 		(*bst) = data.pointer;
240 
241 	return result;
242 }
243 
244 static int
245 acpi_battery_set_alarm(struct acpi_battery *battery, unsigned long alarm)
246 {
247 	acpi_status status = 0;
248 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
249 	struct acpi_object_list arg_list = { 1, &arg0 };
250 
251 
252 	if (!battery)
253 		return -EINVAL;
254 
255 	if (!battery->flags.alarm)
256 		return -ENODEV;
257 
258 	arg0.integer.value = alarm;
259 
260 	status = acpi_evaluate_object(battery->device->handle, "_BTP", &arg_list, NULL);
261 	if (ACPI_FAILURE(status))
262 		return -ENODEV;
263 
264 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", (u32) alarm));
265 
266 	battery->alarm = alarm;
267 
268 	return 0;
269 }
270 
271 static int acpi_battery_check(struct acpi_battery *battery)
272 {
273 	int result = 0;
274 	acpi_status status = AE_OK;
275 	acpi_handle handle = NULL;
276 	struct acpi_device *device = NULL;
277 	struct acpi_battery_info *bif = NULL;
278 
279 
280 	if (!battery)
281 		return -EINVAL;
282 
283 	device = battery->device;
284 
285 	result = acpi_bus_get_status(device);
286 	if (result)
287 		return result;
288 
289 	/* Insertion? */
290 
291 	if (!battery->flags.present && device->status.battery_present) {
292 
293 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery inserted\n"));
294 
295 		/* Evalute _BIF to get certain static information */
296 
297 		result = acpi_battery_get_info(battery, &bif);
298 		if (result)
299 			return result;
300 
301 		battery->flags.power_unit = bif->power_unit;
302 		battery->trips.warning = bif->design_capacity_warning;
303 		battery->trips.low = bif->design_capacity_low;
304 		kfree(bif);
305 
306 		/* See if alarms are supported, and if so, set default */
307 
308 		status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
309 		if (ACPI_SUCCESS(status)) {
310 			battery->flags.alarm = 1;
311 			acpi_battery_set_alarm(battery, battery->trips.warning);
312 		}
313 	}
314 
315 	/* Removal? */
316 
317 	else if (battery->flags.present && !device->status.battery_present) {
318 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Battery removed\n"));
319 	}
320 
321 	battery->flags.present = device->status.battery_present;
322 
323 	return result;
324 }
325 
326 static void acpi_battery_check_present(struct acpi_battery *battery)
327 {
328 	if (!battery->flags.present) {
329 		acpi_battery_check(battery);
330 	}
331 }
332 
333 /* --------------------------------------------------------------------------
334                               FS Interface (/proc)
335    -------------------------------------------------------------------------- */
336 
337 static struct proc_dir_entry *acpi_battery_dir;
338 static int acpi_battery_read_info(struct seq_file *seq, void *offset)
339 {
340 	int result = 0;
341 	struct acpi_battery *battery = seq->private;
342 	struct acpi_battery_info *bif = NULL;
343 	char *units = "?";
344 
345 
346 	if (!battery)
347 		goto end;
348 
349 	acpi_battery_check_present(battery);
350 
351 	if (battery->flags.present)
352 		seq_printf(seq, "present:                 yes\n");
353 	else {
354 		seq_printf(seq, "present:                 no\n");
355 		goto end;
356 	}
357 
358 	/* Battery Info (_BIF) */
359 
360 	result = acpi_battery_get_info(battery, &bif);
361 	if (result || !bif) {
362 		seq_printf(seq, "ERROR: Unable to read battery information\n");
363 		goto end;
364 	}
365 
366 	units =
367 	    bif->
368 	    power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
369 
370 	if (bif->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
371 		seq_printf(seq, "design capacity:         unknown\n");
372 	else
373 		seq_printf(seq, "design capacity:         %d %sh\n",
374 			   (u32) bif->design_capacity, units);
375 
376 	if (bif->last_full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
377 		seq_printf(seq, "last full capacity:      unknown\n");
378 	else
379 		seq_printf(seq, "last full capacity:      %d %sh\n",
380 			   (u32) bif->last_full_capacity, units);
381 
382 	switch ((u32) bif->battery_technology) {
383 	case 0:
384 		seq_printf(seq, "battery technology:      non-rechargeable\n");
385 		break;
386 	case 1:
387 		seq_printf(seq, "battery technology:      rechargeable\n");
388 		break;
389 	default:
390 		seq_printf(seq, "battery technology:      unknown\n");
391 		break;
392 	}
393 
394 	if (bif->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
395 		seq_printf(seq, "design voltage:          unknown\n");
396 	else
397 		seq_printf(seq, "design voltage:          %d mV\n",
398 			   (u32) bif->design_voltage);
399 
400 	seq_printf(seq, "design capacity warning: %d %sh\n",
401 		   (u32) bif->design_capacity_warning, units);
402 	seq_printf(seq, "design capacity low:     %d %sh\n",
403 		   (u32) bif->design_capacity_low, units);
404 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
405 		   (u32) bif->battery_capacity_granularity_1, units);
406 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
407 		   (u32) bif->battery_capacity_granularity_2, units);
408 	seq_printf(seq, "model number:            %s\n", bif->model_number);
409 	seq_printf(seq, "serial number:           %s\n", bif->serial_number);
410 	seq_printf(seq, "battery type:            %s\n", bif->battery_type);
411 	seq_printf(seq, "OEM info:                %s\n", bif->oem_info);
412 
413       end:
414 	kfree(bif);
415 
416 	return 0;
417 }
418 
419 static int acpi_battery_info_open_fs(struct inode *inode, struct file *file)
420 {
421 	return single_open(file, acpi_battery_read_info, PDE(inode)->data);
422 }
423 
424 static int acpi_battery_read_state(struct seq_file *seq, void *offset)
425 {
426 	int result = 0;
427 	struct acpi_battery *battery = seq->private;
428 	struct acpi_battery_status *bst = NULL;
429 	char *units = "?";
430 
431 
432 	if (!battery)
433 		goto end;
434 
435 	acpi_battery_check_present(battery);
436 
437 	if (battery->flags.present)
438 		seq_printf(seq, "present:                 yes\n");
439 	else {
440 		seq_printf(seq, "present:                 no\n");
441 		goto end;
442 	}
443 
444 	/* Battery Units */
445 
446 	units =
447 	    battery->flags.
448 	    power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
449 
450 	/* Battery Status (_BST) */
451 
452 	result = acpi_battery_get_status(battery, &bst);
453 	if (result || !bst) {
454 		seq_printf(seq, "ERROR: Unable to read battery status\n");
455 		goto end;
456 	}
457 
458 	if (!(bst->state & 0x04))
459 		seq_printf(seq, "capacity state:          ok\n");
460 	else
461 		seq_printf(seq, "capacity state:          critical\n");
462 
463 	if ((bst->state & 0x01) && (bst->state & 0x02)) {
464 		seq_printf(seq,
465 			   "charging state:          charging/discharging\n");
466 	} else if (bst->state & 0x01)
467 		seq_printf(seq, "charging state:          discharging\n");
468 	else if (bst->state & 0x02)
469 		seq_printf(seq, "charging state:          charging\n");
470 	else {
471 		seq_printf(seq, "charging state:          charged\n");
472 	}
473 
474 	if (bst->present_rate == ACPI_BATTERY_VALUE_UNKNOWN)
475 		seq_printf(seq, "present rate:            unknown\n");
476 	else
477 		seq_printf(seq, "present rate:            %d %s\n",
478 			   (u32) bst->present_rate, units);
479 
480 	if (bst->remaining_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
481 		seq_printf(seq, "remaining capacity:      unknown\n");
482 	else
483 		seq_printf(seq, "remaining capacity:      %d %sh\n",
484 			   (u32) bst->remaining_capacity, units);
485 
486 	if (bst->present_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
487 		seq_printf(seq, "present voltage:         unknown\n");
488 	else
489 		seq_printf(seq, "present voltage:         %d mV\n",
490 			   (u32) bst->present_voltage);
491 
492       end:
493 	kfree(bst);
494 
495 	return 0;
496 }
497 
498 static int acpi_battery_state_open_fs(struct inode *inode, struct file *file)
499 {
500 	return single_open(file, acpi_battery_read_state, PDE(inode)->data);
501 }
502 
503 static int acpi_battery_read_alarm(struct seq_file *seq, void *offset)
504 {
505 	struct acpi_battery *battery = seq->private;
506 	char *units = "?";
507 
508 
509 	if (!battery)
510 		goto end;
511 
512 	acpi_battery_check_present(battery);
513 
514 	if (!battery->flags.present) {
515 		seq_printf(seq, "present:                 no\n");
516 		goto end;
517 	}
518 
519 	/* Battery Units */
520 
521 	units =
522 	    battery->flags.
523 	    power_unit ? ACPI_BATTERY_UNITS_AMPS : ACPI_BATTERY_UNITS_WATTS;
524 
525 	/* Battery Alarm */
526 
527 	seq_printf(seq, "alarm:                   ");
528 	if (!battery->alarm)
529 		seq_printf(seq, "unsupported\n");
530 	else
531 		seq_printf(seq, "%d %sh\n", (u32) battery->alarm, units);
532 
533       end:
534 	return 0;
535 }
536 
537 static ssize_t
538 acpi_battery_write_alarm(struct file *file,
539 			 const char __user * buffer,
540 			 size_t count, loff_t * ppos)
541 {
542 	int result = 0;
543 	char alarm_string[12] = { '\0' };
544 	struct seq_file *m = file->private_data;
545 	struct acpi_battery *battery = m->private;
546 
547 
548 	if (!battery || (count > sizeof(alarm_string) - 1))
549 		return -EINVAL;
550 
551 	acpi_battery_check_present(battery);
552 
553 	if (!battery->flags.present)
554 		return -ENODEV;
555 
556 	if (copy_from_user(alarm_string, buffer, count))
557 		return -EFAULT;
558 
559 	alarm_string[count] = '\0';
560 
561 	result = acpi_battery_set_alarm(battery,
562 					simple_strtoul(alarm_string, NULL, 0));
563 	if (result)
564 		return result;
565 
566 	return count;
567 }
568 
569 static int acpi_battery_alarm_open_fs(struct inode *inode, struct file *file)
570 {
571 	return single_open(file, acpi_battery_read_alarm, PDE(inode)->data);
572 }
573 
574 static const struct file_operations acpi_battery_info_ops = {
575 	.open = acpi_battery_info_open_fs,
576 	.read = seq_read,
577 	.llseek = seq_lseek,
578 	.release = single_release,
579 	.owner = THIS_MODULE,
580 };
581 
582 static const struct file_operations acpi_battery_state_ops = {
583 	.open = acpi_battery_state_open_fs,
584 	.read = seq_read,
585 	.llseek = seq_lseek,
586 	.release = single_release,
587 	.owner = THIS_MODULE,
588 };
589 
590 static const struct file_operations acpi_battery_alarm_ops = {
591 	.open = acpi_battery_alarm_open_fs,
592 	.read = seq_read,
593 	.write = acpi_battery_write_alarm,
594 	.llseek = seq_lseek,
595 	.release = single_release,
596 	.owner = THIS_MODULE,
597 };
598 
599 static int acpi_battery_add_fs(struct acpi_device *device)
600 {
601 	struct proc_dir_entry *entry = NULL;
602 
603 
604 	if (!acpi_device_dir(device)) {
605 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
606 						     acpi_battery_dir);
607 		if (!acpi_device_dir(device))
608 			return -ENODEV;
609 		acpi_device_dir(device)->owner = THIS_MODULE;
610 	}
611 
612 	/* 'info' [R] */
613 	entry = create_proc_entry(ACPI_BATTERY_FILE_INFO,
614 				  S_IRUGO, acpi_device_dir(device));
615 	if (!entry)
616 		return -ENODEV;
617 	else {
618 		entry->proc_fops = &acpi_battery_info_ops;
619 		entry->data = acpi_driver_data(device);
620 		entry->owner = THIS_MODULE;
621 	}
622 
623 	/* 'status' [R] */
624 	entry = create_proc_entry(ACPI_BATTERY_FILE_STATUS,
625 				  S_IRUGO, acpi_device_dir(device));
626 	if (!entry)
627 		return -ENODEV;
628 	else {
629 		entry->proc_fops = &acpi_battery_state_ops;
630 		entry->data = acpi_driver_data(device);
631 		entry->owner = THIS_MODULE;
632 	}
633 
634 	/* 'alarm' [R/W] */
635 	entry = create_proc_entry(ACPI_BATTERY_FILE_ALARM,
636 				  S_IFREG | S_IRUGO | S_IWUSR,
637 				  acpi_device_dir(device));
638 	if (!entry)
639 		return -ENODEV;
640 	else {
641 		entry->proc_fops = &acpi_battery_alarm_ops;
642 		entry->data = acpi_driver_data(device);
643 		entry->owner = THIS_MODULE;
644 	}
645 
646 	return 0;
647 }
648 
649 static int acpi_battery_remove_fs(struct acpi_device *device)
650 {
651 
652 	if (acpi_device_dir(device)) {
653 		remove_proc_entry(ACPI_BATTERY_FILE_ALARM,
654 				  acpi_device_dir(device));
655 		remove_proc_entry(ACPI_BATTERY_FILE_STATUS,
656 				  acpi_device_dir(device));
657 		remove_proc_entry(ACPI_BATTERY_FILE_INFO,
658 				  acpi_device_dir(device));
659 
660 		remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
661 		acpi_device_dir(device) = NULL;
662 	}
663 
664 	return 0;
665 }
666 
667 /* --------------------------------------------------------------------------
668                                  Driver Interface
669    -------------------------------------------------------------------------- */
670 
671 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
672 {
673 	struct acpi_battery *battery = data;
674 	struct acpi_device *device = NULL;
675 
676 
677 	if (!battery)
678 		return;
679 
680 	device = battery->device;
681 
682 	switch (event) {
683 	case ACPI_BATTERY_NOTIFY_STATUS:
684 	case ACPI_BATTERY_NOTIFY_INFO:
685 	case ACPI_NOTIFY_BUS_CHECK:
686 	case ACPI_NOTIFY_DEVICE_CHECK:
687 		acpi_battery_check(battery);
688 		acpi_bus_generate_event(device, event, battery->flags.present);
689 		break;
690 	default:
691 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
692 				  "Unsupported event [0x%x]\n", event));
693 		break;
694 	}
695 
696 	return;
697 }
698 
699 static int acpi_battery_add(struct acpi_device *device)
700 {
701 	int result = 0;
702 	acpi_status status = 0;
703 	struct acpi_battery *battery = NULL;
704 
705 
706 	if (!device)
707 		return -EINVAL;
708 
709 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
710 	if (!battery)
711 		return -ENOMEM;
712 
713 	battery->device = device;
714 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
715 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
716 	acpi_driver_data(device) = battery;
717 
718 	result = acpi_battery_check(battery);
719 	if (result)
720 		goto end;
721 
722 	result = acpi_battery_add_fs(device);
723 	if (result)
724 		goto end;
725 
726 	status = acpi_install_notify_handler(device->handle,
727 					     ACPI_ALL_NOTIFY,
728 					     acpi_battery_notify, battery);
729 	if (ACPI_FAILURE(status)) {
730 		result = -ENODEV;
731 		goto end;
732 	}
733 
734 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
735 	       ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
736 	       device->status.battery_present ? "present" : "absent");
737 
738       end:
739 	if (result) {
740 		acpi_battery_remove_fs(device);
741 		kfree(battery);
742 	}
743 
744 	return result;
745 }
746 
747 static int acpi_battery_remove(struct acpi_device *device, int type)
748 {
749 	acpi_status status = 0;
750 	struct acpi_battery *battery = NULL;
751 
752 
753 	if (!device || !acpi_driver_data(device))
754 		return -EINVAL;
755 
756 	battery = acpi_driver_data(device);
757 
758 	status = acpi_remove_notify_handler(device->handle,
759 					    ACPI_ALL_NOTIFY,
760 					    acpi_battery_notify);
761 
762 	acpi_battery_remove_fs(device);
763 
764 	kfree(battery);
765 
766 	return 0;
767 }
768 
769 /* this is needed to learn about changes made in suspended state */
770 static int acpi_battery_resume(struct acpi_device *device)
771 {
772 	struct acpi_battery *battery;
773 
774 	if (!device)
775 		return -EINVAL;
776 
777 	battery = device->driver_data;
778 	return acpi_battery_check(battery);
779 }
780 
781 static int __init acpi_battery_init(void)
782 {
783 	int result;
784 
785 	if (acpi_disabled)
786 		return -ENODEV;
787 
788 	acpi_battery_dir = acpi_lock_battery_dir();
789 	if (!acpi_battery_dir)
790 		return -ENODEV;
791 
792 	result = acpi_bus_register_driver(&acpi_battery_driver);
793 	if (result < 0) {
794 		acpi_unlock_battery_dir(acpi_battery_dir);
795 		return -ENODEV;
796 	}
797 
798 	return 0;
799 }
800 
801 static void __exit acpi_battery_exit(void)
802 {
803 
804 	acpi_bus_unregister_driver(&acpi_battery_driver);
805 
806 	acpi_unlock_battery_dir(acpi_battery_dir);
807 
808 	return;
809 }
810 
811 module_init(acpi_battery_init);
812 module_exit(acpi_battery_exit);
813