xref: /openbmc/linux/drivers/acpi/battery.c (revision b627b4ed)
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 #include <linux/async.h>
34 
35 #ifdef CONFIG_ACPI_PROCFS_POWER
36 #include <linux/proc_fs.h>
37 #include <linux/seq_file.h>
38 #include <asm/uaccess.h>
39 #endif
40 
41 #include <acpi/acpi_bus.h>
42 #include <acpi/acpi_drivers.h>
43 
44 #ifdef CONFIG_ACPI_SYSFS_POWER
45 #include <linux/power_supply.h>
46 #endif
47 
48 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
49 
50 #define ACPI_BATTERY_CLASS		"battery"
51 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
52 #define ACPI_BATTERY_NOTIFY_STATUS	0x80
53 #define ACPI_BATTERY_NOTIFY_INFO	0x81
54 
55 #define _COMPONENT		ACPI_BATTERY_COMPONENT
56 
57 ACPI_MODULE_NAME("battery");
58 
59 MODULE_AUTHOR("Paul Diefenbaugh");
60 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
61 MODULE_DESCRIPTION("ACPI Battery Driver");
62 MODULE_LICENSE("GPL");
63 
64 static unsigned int cache_time = 1000;
65 module_param(cache_time, uint, 0644);
66 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
67 
68 #ifdef CONFIG_ACPI_PROCFS_POWER
69 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
70 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
71 
72 enum acpi_battery_files {
73 	info_tag = 0,
74 	state_tag,
75 	alarm_tag,
76 	ACPI_BATTERY_NUMFILES,
77 };
78 
79 #endif
80 
81 static const struct acpi_device_id battery_device_ids[] = {
82 	{"PNP0C0A", 0},
83 	{"", 0},
84 };
85 
86 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
87 
88 
89 struct acpi_battery {
90 	struct mutex lock;
91 #ifdef CONFIG_ACPI_SYSFS_POWER
92 	struct power_supply bat;
93 #endif
94 	struct acpi_device *device;
95 	unsigned long update_time;
96 	int rate_now;
97 	int capacity_now;
98 	int voltage_now;
99 	int design_capacity;
100 	int full_charge_capacity;
101 	int technology;
102 	int design_voltage;
103 	int design_capacity_warning;
104 	int design_capacity_low;
105 	int capacity_granularity_1;
106 	int capacity_granularity_2;
107 	int alarm;
108 	char model_number[32];
109 	char serial_number[32];
110 	char type[32];
111 	char oem_info[32];
112 	int state;
113 	int power_unit;
114 	u8 alarm_present;
115 };
116 
117 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
118 
119 inline int acpi_battery_present(struct acpi_battery *battery)
120 {
121 	return battery->device->status.battery_present;
122 }
123 
124 #ifdef CONFIG_ACPI_SYSFS_POWER
125 static int acpi_battery_technology(struct acpi_battery *battery)
126 {
127 	if (!strcasecmp("NiCd", battery->type))
128 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
129 	if (!strcasecmp("NiMH", battery->type))
130 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
131 	if (!strcasecmp("LION", battery->type))
132 		return POWER_SUPPLY_TECHNOLOGY_LION;
133 	if (!strncasecmp("LI-ION", battery->type, 6))
134 		return POWER_SUPPLY_TECHNOLOGY_LION;
135 	if (!strcasecmp("LiP", battery->type))
136 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
137 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
138 }
139 
140 static int acpi_battery_get_state(struct acpi_battery *battery);
141 
142 static int acpi_battery_is_charged(struct acpi_battery *battery)
143 {
144 	/* either charging or discharging */
145 	if (battery->state != 0)
146 		return 0;
147 
148 	/* battery not reporting charge */
149 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
150 	    battery->capacity_now == 0)
151 		return 0;
152 
153 	/* good batteries update full_charge as the batteries degrade */
154 	if (battery->full_charge_capacity == battery->capacity_now)
155 		return 1;
156 
157 	/* fallback to using design values for broken batteries */
158 	if (battery->design_capacity == battery->capacity_now)
159 		return 1;
160 
161 	/* we don't do any sort of metric based on percentages */
162 	return 0;
163 }
164 
165 static int acpi_battery_get_property(struct power_supply *psy,
166 				     enum power_supply_property psp,
167 				     union power_supply_propval *val)
168 {
169 	struct acpi_battery *battery = to_acpi_battery(psy);
170 
171 	if (acpi_battery_present(battery)) {
172 		/* run battery update only if it is present */
173 		acpi_battery_get_state(battery);
174 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
175 		return -ENODEV;
176 	switch (psp) {
177 	case POWER_SUPPLY_PROP_STATUS:
178 		if (battery->state & 0x01)
179 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
180 		else if (battery->state & 0x02)
181 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
182 		else if (acpi_battery_is_charged(battery))
183 			val->intval = POWER_SUPPLY_STATUS_FULL;
184 		else
185 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
186 		break;
187 	case POWER_SUPPLY_PROP_PRESENT:
188 		val->intval = acpi_battery_present(battery);
189 		break;
190 	case POWER_SUPPLY_PROP_TECHNOLOGY:
191 		val->intval = acpi_battery_technology(battery);
192 		break;
193 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
194 		val->intval = battery->design_voltage * 1000;
195 		break;
196 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
197 		val->intval = battery->voltage_now * 1000;
198 		break;
199 	case POWER_SUPPLY_PROP_CURRENT_NOW:
200 	case POWER_SUPPLY_PROP_POWER_NOW:
201 		val->intval = battery->rate_now * 1000;
202 		break;
203 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
204 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
205 		val->intval = battery->design_capacity * 1000;
206 		break;
207 	case POWER_SUPPLY_PROP_CHARGE_FULL:
208 	case POWER_SUPPLY_PROP_ENERGY_FULL:
209 		val->intval = battery->full_charge_capacity * 1000;
210 		break;
211 	case POWER_SUPPLY_PROP_CHARGE_NOW:
212 	case POWER_SUPPLY_PROP_ENERGY_NOW:
213 		val->intval = battery->capacity_now * 1000;
214 		break;
215 	case POWER_SUPPLY_PROP_MODEL_NAME:
216 		val->strval = battery->model_number;
217 		break;
218 	case POWER_SUPPLY_PROP_MANUFACTURER:
219 		val->strval = battery->oem_info;
220 		break;
221 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
222 		val->strval = battery->serial_number;
223 		break;
224 	default:
225 		return -EINVAL;
226 	}
227 	return 0;
228 }
229 
230 static enum power_supply_property charge_battery_props[] = {
231 	POWER_SUPPLY_PROP_STATUS,
232 	POWER_SUPPLY_PROP_PRESENT,
233 	POWER_SUPPLY_PROP_TECHNOLOGY,
234 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
235 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
236 	POWER_SUPPLY_PROP_CURRENT_NOW,
237 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
238 	POWER_SUPPLY_PROP_CHARGE_FULL,
239 	POWER_SUPPLY_PROP_CHARGE_NOW,
240 	POWER_SUPPLY_PROP_MODEL_NAME,
241 	POWER_SUPPLY_PROP_MANUFACTURER,
242 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
243 };
244 
245 static enum power_supply_property energy_battery_props[] = {
246 	POWER_SUPPLY_PROP_STATUS,
247 	POWER_SUPPLY_PROP_PRESENT,
248 	POWER_SUPPLY_PROP_TECHNOLOGY,
249 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
250 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
251 	POWER_SUPPLY_PROP_CURRENT_NOW,
252 	POWER_SUPPLY_PROP_POWER_NOW,
253 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
254 	POWER_SUPPLY_PROP_ENERGY_FULL,
255 	POWER_SUPPLY_PROP_ENERGY_NOW,
256 	POWER_SUPPLY_PROP_MODEL_NAME,
257 	POWER_SUPPLY_PROP_MANUFACTURER,
258 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
259 };
260 #endif
261 
262 #ifdef CONFIG_ACPI_PROCFS_POWER
263 inline char *acpi_battery_units(struct acpi_battery *battery)
264 {
265 	return (battery->power_unit)?"mA":"mW";
266 }
267 #endif
268 
269 /* --------------------------------------------------------------------------
270                                Battery Management
271    -------------------------------------------------------------------------- */
272 struct acpi_offsets {
273 	size_t offset;		/* offset inside struct acpi_sbs_battery */
274 	u8 mode;		/* int or string? */
275 };
276 
277 static struct acpi_offsets state_offsets[] = {
278 	{offsetof(struct acpi_battery, state), 0},
279 	{offsetof(struct acpi_battery, rate_now), 0},
280 	{offsetof(struct acpi_battery, capacity_now), 0},
281 	{offsetof(struct acpi_battery, voltage_now), 0},
282 };
283 
284 static struct acpi_offsets info_offsets[] = {
285 	{offsetof(struct acpi_battery, power_unit), 0},
286 	{offsetof(struct acpi_battery, design_capacity), 0},
287 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
288 	{offsetof(struct acpi_battery, technology), 0},
289 	{offsetof(struct acpi_battery, design_voltage), 0},
290 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
291 	{offsetof(struct acpi_battery, design_capacity_low), 0},
292 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
293 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
294 	{offsetof(struct acpi_battery, model_number), 1},
295 	{offsetof(struct acpi_battery, serial_number), 1},
296 	{offsetof(struct acpi_battery, type), 1},
297 	{offsetof(struct acpi_battery, oem_info), 1},
298 };
299 
300 static int extract_package(struct acpi_battery *battery,
301 			   union acpi_object *package,
302 			   struct acpi_offsets *offsets, int num)
303 {
304 	int i;
305 	union acpi_object *element;
306 	if (package->type != ACPI_TYPE_PACKAGE)
307 		return -EFAULT;
308 	for (i = 0; i < num; ++i) {
309 		if (package->package.count <= i)
310 			return -EFAULT;
311 		element = &package->package.elements[i];
312 		if (offsets[i].mode) {
313 			u8 *ptr = (u8 *)battery + offsets[i].offset;
314 			if (element->type == ACPI_TYPE_STRING ||
315 			    element->type == ACPI_TYPE_BUFFER)
316 				strncpy(ptr, element->string.pointer, 32);
317 			else if (element->type == ACPI_TYPE_INTEGER) {
318 				strncpy(ptr, (u8 *)&element->integer.value,
319 					sizeof(acpi_integer));
320 				ptr[sizeof(acpi_integer)] = 0;
321 			} else
322 				*ptr = 0; /* don't have value */
323 		} else {
324 			int *x = (int *)((u8 *)battery + offsets[i].offset);
325 			*x = (element->type == ACPI_TYPE_INTEGER) ?
326 				element->integer.value : -1;
327 		}
328 	}
329 	return 0;
330 }
331 
332 static int acpi_battery_get_status(struct acpi_battery *battery)
333 {
334 	if (acpi_bus_get_status(battery->device)) {
335 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
336 		return -ENODEV;
337 	}
338 	return 0;
339 }
340 
341 static int acpi_battery_get_info(struct acpi_battery *battery)
342 {
343 	int result = -EFAULT;
344 	acpi_status status = 0;
345 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
346 
347 	if (!acpi_battery_present(battery))
348 		return 0;
349 	mutex_lock(&battery->lock);
350 	status = acpi_evaluate_object(battery->device->handle, "_BIF",
351 				      NULL, &buffer);
352 	mutex_unlock(&battery->lock);
353 
354 	if (ACPI_FAILURE(status)) {
355 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
356 		return -ENODEV;
357 	}
358 
359 	result = extract_package(battery, buffer.pointer,
360 				 info_offsets, ARRAY_SIZE(info_offsets));
361 	kfree(buffer.pointer);
362 	return result;
363 }
364 
365 static int acpi_battery_get_state(struct acpi_battery *battery)
366 {
367 	int result = 0;
368 	acpi_status status = 0;
369 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
370 
371 	if (!acpi_battery_present(battery))
372 		return 0;
373 
374 	if (battery->update_time &&
375 	    time_before(jiffies, battery->update_time +
376 			msecs_to_jiffies(cache_time)))
377 		return 0;
378 
379 	mutex_lock(&battery->lock);
380 	status = acpi_evaluate_object(battery->device->handle, "_BST",
381 				      NULL, &buffer);
382 	mutex_unlock(&battery->lock);
383 
384 	if (ACPI_FAILURE(status)) {
385 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
386 		return -ENODEV;
387 	}
388 
389 	result = extract_package(battery, buffer.pointer,
390 				 state_offsets, ARRAY_SIZE(state_offsets));
391 	battery->update_time = jiffies;
392 	kfree(buffer.pointer);
393 	return result;
394 }
395 
396 static int acpi_battery_set_alarm(struct acpi_battery *battery)
397 {
398 	acpi_status status = 0;
399 	union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
400 	struct acpi_object_list arg_list = { 1, &arg0 };
401 
402 	if (!acpi_battery_present(battery)|| !battery->alarm_present)
403 		return -ENODEV;
404 
405 	arg0.integer.value = battery->alarm;
406 
407 	mutex_lock(&battery->lock);
408 	status = acpi_evaluate_object(battery->device->handle, "_BTP",
409 				 &arg_list, NULL);
410 	mutex_unlock(&battery->lock);
411 
412 	if (ACPI_FAILURE(status))
413 		return -ENODEV;
414 
415 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
416 	return 0;
417 }
418 
419 static int acpi_battery_init_alarm(struct acpi_battery *battery)
420 {
421 	acpi_status status = AE_OK;
422 	acpi_handle handle = NULL;
423 
424 	/* See if alarms are supported, and if so, set default */
425 	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
426 	if (ACPI_FAILURE(status)) {
427 		battery->alarm_present = 0;
428 		return 0;
429 	}
430 	battery->alarm_present = 1;
431 	if (!battery->alarm)
432 		battery->alarm = battery->design_capacity_warning;
433 	return acpi_battery_set_alarm(battery);
434 }
435 
436 #ifdef CONFIG_ACPI_SYSFS_POWER
437 static ssize_t acpi_battery_alarm_show(struct device *dev,
438 					struct device_attribute *attr,
439 					char *buf)
440 {
441 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
442 	return sprintf(buf, "%d\n", battery->alarm * 1000);
443 }
444 
445 static ssize_t acpi_battery_alarm_store(struct device *dev,
446 					struct device_attribute *attr,
447 					const char *buf, size_t count)
448 {
449 	unsigned long x;
450 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
451 	if (sscanf(buf, "%ld\n", &x) == 1)
452 		battery->alarm = x/1000;
453 	if (acpi_battery_present(battery))
454 		acpi_battery_set_alarm(battery);
455 	return count;
456 }
457 
458 static struct device_attribute alarm_attr = {
459 	.attr = {.name = "alarm", .mode = 0644},
460 	.show = acpi_battery_alarm_show,
461 	.store = acpi_battery_alarm_store,
462 };
463 
464 static int sysfs_add_battery(struct acpi_battery *battery)
465 {
466 	int result;
467 
468 	if (battery->power_unit) {
469 		battery->bat.properties = charge_battery_props;
470 		battery->bat.num_properties =
471 			ARRAY_SIZE(charge_battery_props);
472 	} else {
473 		battery->bat.properties = energy_battery_props;
474 		battery->bat.num_properties =
475 			ARRAY_SIZE(energy_battery_props);
476 	}
477 
478 	battery->bat.name = acpi_device_bid(battery->device);
479 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
480 	battery->bat.get_property = acpi_battery_get_property;
481 
482 	result = power_supply_register(&battery->device->dev, &battery->bat);
483 	if (result)
484 		return result;
485 	return device_create_file(battery->bat.dev, &alarm_attr);
486 }
487 
488 static void sysfs_remove_battery(struct acpi_battery *battery)
489 {
490 	if (!battery->bat.dev)
491 		return;
492 	device_remove_file(battery->bat.dev, &alarm_attr);
493 	power_supply_unregister(&battery->bat);
494 	battery->bat.dev = NULL;
495 }
496 #endif
497 
498 static int acpi_battery_update(struct acpi_battery *battery)
499 {
500 	int result, old_present = acpi_battery_present(battery);
501 	result = acpi_battery_get_status(battery);
502 	if (result)
503 		return result;
504 #ifdef CONFIG_ACPI_SYSFS_POWER
505 	if (!acpi_battery_present(battery)) {
506 		sysfs_remove_battery(battery);
507 		battery->update_time = 0;
508 		return 0;
509 	}
510 #endif
511 	if (!battery->update_time ||
512 	    old_present != acpi_battery_present(battery)) {
513 		result = acpi_battery_get_info(battery);
514 		if (result)
515 			return result;
516 		acpi_battery_init_alarm(battery);
517 	}
518 #ifdef CONFIG_ACPI_SYSFS_POWER
519 	if (!battery->bat.dev)
520 		sysfs_add_battery(battery);
521 #endif
522 	return acpi_battery_get_state(battery);
523 }
524 
525 /* --------------------------------------------------------------------------
526                               FS Interface (/proc)
527    -------------------------------------------------------------------------- */
528 
529 #ifdef CONFIG_ACPI_PROCFS_POWER
530 static struct proc_dir_entry *acpi_battery_dir;
531 
532 static int acpi_battery_print_info(struct seq_file *seq, int result)
533 {
534 	struct acpi_battery *battery = seq->private;
535 
536 	if (result)
537 		goto end;
538 
539 	seq_printf(seq, "present:                 %s\n",
540 		   acpi_battery_present(battery)?"yes":"no");
541 	if (!acpi_battery_present(battery))
542 		goto end;
543 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
544 		seq_printf(seq, "design capacity:         unknown\n");
545 	else
546 		seq_printf(seq, "design capacity:         %d %sh\n",
547 			   battery->design_capacity,
548 			   acpi_battery_units(battery));
549 
550 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
551 		seq_printf(seq, "last full capacity:      unknown\n");
552 	else
553 		seq_printf(seq, "last full capacity:      %d %sh\n",
554 			   battery->full_charge_capacity,
555 			   acpi_battery_units(battery));
556 
557 	seq_printf(seq, "battery technology:      %srechargeable\n",
558 		   (!battery->technology)?"non-":"");
559 
560 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
561 		seq_printf(seq, "design voltage:          unknown\n");
562 	else
563 		seq_printf(seq, "design voltage:          %d mV\n",
564 			   battery->design_voltage);
565 	seq_printf(seq, "design capacity warning: %d %sh\n",
566 		   battery->design_capacity_warning,
567 		   acpi_battery_units(battery));
568 	seq_printf(seq, "design capacity low:     %d %sh\n",
569 		   battery->design_capacity_low,
570 		   acpi_battery_units(battery));
571 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
572 		   battery->capacity_granularity_1,
573 		   acpi_battery_units(battery));
574 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
575 		   battery->capacity_granularity_2,
576 		   acpi_battery_units(battery));
577 	seq_printf(seq, "model number:            %s\n", battery->model_number);
578 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
579 	seq_printf(seq, "battery type:            %s\n", battery->type);
580 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
581       end:
582 	if (result)
583 		seq_printf(seq, "ERROR: Unable to read battery info\n");
584 	return result;
585 }
586 
587 static int acpi_battery_print_state(struct seq_file *seq, int result)
588 {
589 	struct acpi_battery *battery = seq->private;
590 
591 	if (result)
592 		goto end;
593 
594 	seq_printf(seq, "present:                 %s\n",
595 		   acpi_battery_present(battery)?"yes":"no");
596 	if (!acpi_battery_present(battery))
597 		goto end;
598 
599 	seq_printf(seq, "capacity state:          %s\n",
600 			(battery->state & 0x04)?"critical":"ok");
601 	if ((battery->state & 0x01) && (battery->state & 0x02))
602 		seq_printf(seq,
603 			   "charging state:          charging/discharging\n");
604 	else if (battery->state & 0x01)
605 		seq_printf(seq, "charging state:          discharging\n");
606 	else if (battery->state & 0x02)
607 		seq_printf(seq, "charging state:          charging\n");
608 	else
609 		seq_printf(seq, "charging state:          charged\n");
610 
611 	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
612 		seq_printf(seq, "present rate:            unknown\n");
613 	else
614 		seq_printf(seq, "present rate:            %d %s\n",
615 			   battery->rate_now, acpi_battery_units(battery));
616 
617 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
618 		seq_printf(seq, "remaining capacity:      unknown\n");
619 	else
620 		seq_printf(seq, "remaining capacity:      %d %sh\n",
621 			   battery->capacity_now, acpi_battery_units(battery));
622 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
623 		seq_printf(seq, "present voltage:         unknown\n");
624 	else
625 		seq_printf(seq, "present voltage:         %d mV\n",
626 			   battery->voltage_now);
627       end:
628 	if (result)
629 		seq_printf(seq, "ERROR: Unable to read battery state\n");
630 
631 	return result;
632 }
633 
634 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
635 {
636 	struct acpi_battery *battery = seq->private;
637 
638 	if (result)
639 		goto end;
640 
641 	if (!acpi_battery_present(battery)) {
642 		seq_printf(seq, "present:                 no\n");
643 		goto end;
644 	}
645 	seq_printf(seq, "alarm:                   ");
646 	if (!battery->alarm)
647 		seq_printf(seq, "unsupported\n");
648 	else
649 		seq_printf(seq, "%u %sh\n", battery->alarm,
650 				acpi_battery_units(battery));
651       end:
652 	if (result)
653 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
654 	return result;
655 }
656 
657 static ssize_t acpi_battery_write_alarm(struct file *file,
658 					const char __user * buffer,
659 					size_t count, loff_t * ppos)
660 {
661 	int result = 0;
662 	char alarm_string[12] = { '\0' };
663 	struct seq_file *m = file->private_data;
664 	struct acpi_battery *battery = m->private;
665 
666 	if (!battery || (count > sizeof(alarm_string) - 1))
667 		return -EINVAL;
668 	if (!acpi_battery_present(battery)) {
669 		result = -ENODEV;
670 		goto end;
671 	}
672 	if (copy_from_user(alarm_string, buffer, count)) {
673 		result = -EFAULT;
674 		goto end;
675 	}
676 	alarm_string[count] = '\0';
677 	battery->alarm = simple_strtol(alarm_string, NULL, 0);
678 	result = acpi_battery_set_alarm(battery);
679       end:
680 	if (!result)
681 		return count;
682 	return result;
683 }
684 
685 typedef int(*print_func)(struct seq_file *seq, int result);
686 
687 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
688 	acpi_battery_print_info,
689 	acpi_battery_print_state,
690 	acpi_battery_print_alarm,
691 };
692 
693 static int acpi_battery_read(int fid, struct seq_file *seq)
694 {
695 	struct acpi_battery *battery = seq->private;
696 	int result = acpi_battery_update(battery);
697 	return acpi_print_funcs[fid](seq, result);
698 }
699 
700 #define DECLARE_FILE_FUNCTIONS(_name) \
701 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
702 { \
703 	return acpi_battery_read(_name##_tag, seq); \
704 } \
705 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
706 { \
707 	return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
708 }
709 
710 DECLARE_FILE_FUNCTIONS(info);
711 DECLARE_FILE_FUNCTIONS(state);
712 DECLARE_FILE_FUNCTIONS(alarm);
713 
714 #undef DECLARE_FILE_FUNCTIONS
715 
716 #define FILE_DESCRIPTION_RO(_name) \
717 	{ \
718 	.name = __stringify(_name), \
719 	.mode = S_IRUGO, \
720 	.ops = { \
721 		.open = acpi_battery_##_name##_open_fs, \
722 		.read = seq_read, \
723 		.llseek = seq_lseek, \
724 		.release = single_release, \
725 		.owner = THIS_MODULE, \
726 		}, \
727 	}
728 
729 #define FILE_DESCRIPTION_RW(_name) \
730 	{ \
731 	.name = __stringify(_name), \
732 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
733 	.ops = { \
734 		.open = acpi_battery_##_name##_open_fs, \
735 		.read = seq_read, \
736 		.llseek = seq_lseek, \
737 		.write = acpi_battery_write_##_name, \
738 		.release = single_release, \
739 		.owner = THIS_MODULE, \
740 		}, \
741 	}
742 
743 static struct battery_file {
744 	struct file_operations ops;
745 	mode_t mode;
746 	const char *name;
747 } acpi_battery_file[] = {
748 	FILE_DESCRIPTION_RO(info),
749 	FILE_DESCRIPTION_RO(state),
750 	FILE_DESCRIPTION_RW(alarm),
751 };
752 
753 #undef FILE_DESCRIPTION_RO
754 #undef FILE_DESCRIPTION_RW
755 
756 static int acpi_battery_add_fs(struct acpi_device *device)
757 {
758 	struct proc_dir_entry *entry = NULL;
759 	int i;
760 
761 	if (!acpi_device_dir(device)) {
762 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
763 						     acpi_battery_dir);
764 		if (!acpi_device_dir(device))
765 			return -ENODEV;
766 	}
767 
768 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
769 		entry = proc_create_data(acpi_battery_file[i].name,
770 					 acpi_battery_file[i].mode,
771 					 acpi_device_dir(device),
772 					 &acpi_battery_file[i].ops,
773 					 acpi_driver_data(device));
774 		if (!entry)
775 			return -ENODEV;
776 	}
777 	return 0;
778 }
779 
780 static void acpi_battery_remove_fs(struct acpi_device *device)
781 {
782 	int i;
783 	if (!acpi_device_dir(device))
784 		return;
785 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
786 		remove_proc_entry(acpi_battery_file[i].name,
787 				  acpi_device_dir(device));
788 
789 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
790 	acpi_device_dir(device) = NULL;
791 }
792 
793 #endif
794 
795 /* --------------------------------------------------------------------------
796                                  Driver Interface
797    -------------------------------------------------------------------------- */
798 
799 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
800 {
801 	struct acpi_battery *battery = data;
802 	struct acpi_device *device;
803 	if (!battery)
804 		return;
805 	device = battery->device;
806 	acpi_battery_update(battery);
807 	acpi_bus_generate_proc_event(device, event,
808 				     acpi_battery_present(battery));
809 	acpi_bus_generate_netlink_event(device->pnp.device_class,
810 					dev_name(&device->dev), event,
811 					acpi_battery_present(battery));
812 #ifdef CONFIG_ACPI_SYSFS_POWER
813 	/* acpi_batter_update could remove power_supply object */
814 	if (battery->bat.dev)
815 		kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
816 #endif
817 }
818 
819 static int acpi_battery_add(struct acpi_device *device)
820 {
821 	int result = 0;
822 	acpi_status status = 0;
823 	struct acpi_battery *battery = NULL;
824 	if (!device)
825 		return -EINVAL;
826 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
827 	if (!battery)
828 		return -ENOMEM;
829 	battery->device = device;
830 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
831 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
832 	device->driver_data = battery;
833 	mutex_init(&battery->lock);
834 	acpi_battery_update(battery);
835 #ifdef CONFIG_ACPI_PROCFS_POWER
836 	result = acpi_battery_add_fs(device);
837 	if (result)
838 		goto end;
839 #endif
840 	status = acpi_install_notify_handler(device->handle,
841 					     ACPI_ALL_NOTIFY,
842 					     acpi_battery_notify, battery);
843 	if (ACPI_FAILURE(status)) {
844 		ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
845 		result = -ENODEV;
846 		goto end;
847 	}
848 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
849 	       ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
850 	       device->status.battery_present ? "present" : "absent");
851       end:
852 	if (result) {
853 #ifdef CONFIG_ACPI_PROCFS_POWER
854 		acpi_battery_remove_fs(device);
855 #endif
856 		kfree(battery);
857 	}
858 	return result;
859 }
860 
861 static int acpi_battery_remove(struct acpi_device *device, int type)
862 {
863 	acpi_status status = 0;
864 	struct acpi_battery *battery = NULL;
865 
866 	if (!device || !acpi_driver_data(device))
867 		return -EINVAL;
868 	battery = acpi_driver_data(device);
869 	status = acpi_remove_notify_handler(device->handle,
870 					    ACPI_ALL_NOTIFY,
871 					    acpi_battery_notify);
872 #ifdef CONFIG_ACPI_PROCFS_POWER
873 	acpi_battery_remove_fs(device);
874 #endif
875 #ifdef CONFIG_ACPI_SYSFS_POWER
876 	sysfs_remove_battery(battery);
877 #endif
878 	mutex_destroy(&battery->lock);
879 	kfree(battery);
880 	return 0;
881 }
882 
883 /* this is needed to learn about changes made in suspended state */
884 static int acpi_battery_resume(struct acpi_device *device)
885 {
886 	struct acpi_battery *battery;
887 	if (!device)
888 		return -EINVAL;
889 	battery = acpi_driver_data(device);
890 	battery->update_time = 0;
891 	acpi_battery_update(battery);
892 	return 0;
893 }
894 
895 static struct acpi_driver acpi_battery_driver = {
896 	.name = "battery",
897 	.class = ACPI_BATTERY_CLASS,
898 	.ids = battery_device_ids,
899 	.ops = {
900 		.add = acpi_battery_add,
901 		.resume = acpi_battery_resume,
902 		.remove = acpi_battery_remove,
903 		},
904 };
905 
906 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
907 {
908 	if (acpi_disabled)
909 		return;
910 #ifdef CONFIG_ACPI_PROCFS_POWER
911 	acpi_battery_dir = acpi_lock_battery_dir();
912 	if (!acpi_battery_dir)
913 		return;
914 #endif
915 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
916 #ifdef CONFIG_ACPI_PROCFS_POWER
917 		acpi_unlock_battery_dir(acpi_battery_dir);
918 #endif
919 		return;
920 	}
921 	return;
922 }
923 
924 static int __init acpi_battery_init(void)
925 {
926 	async_schedule(acpi_battery_init_async, NULL);
927 	return 0;
928 }
929 
930 static void __exit acpi_battery_exit(void)
931 {
932 	acpi_bus_unregister_driver(&acpi_battery_driver);
933 #ifdef CONFIG_ACPI_PROCFS_POWER
934 	acpi_unlock_battery_dir(acpi_battery_dir);
935 #endif
936 }
937 
938 module_init(acpi_battery_init);
939 module_exit(acpi_battery_exit);
940