xref: /linux/drivers/acpi/battery.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /*
2  *  battery.c - ACPI Battery Driver (Revision: 2.0)
3  *
4  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
6  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
7  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27 
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/jiffies.h>
33 
34 #ifdef CONFIG_ACPI_PROCFS_POWER
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <asm/uaccess.h>
38 #endif
39 
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
42 
43 #ifdef CONFIG_ACPI_SYSFS_POWER
44 #include <linux/power_supply.h>
45 #endif
46 
47 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
48 
49 #define ACPI_BATTERY_COMPONENT		0x00040000
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 current_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_get_property(struct power_supply *psy,
143 				     enum power_supply_property psp,
144 				     union power_supply_propval *val)
145 {
146 	struct acpi_battery *battery = to_acpi_battery(psy);
147 
148 	if (acpi_battery_present(battery)) {
149 		/* run battery update only if it is present */
150 		acpi_battery_get_state(battery);
151 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
152 		return -ENODEV;
153 	switch (psp) {
154 	case POWER_SUPPLY_PROP_STATUS:
155 		if (battery->state & 0x01)
156 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
157 		else if (battery->state & 0x02)
158 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
159 		else if (battery->state == 0)
160 			val->intval = POWER_SUPPLY_STATUS_FULL;
161 		else
162 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
163 		break;
164 	case POWER_SUPPLY_PROP_PRESENT:
165 		val->intval = acpi_battery_present(battery);
166 		break;
167 	case POWER_SUPPLY_PROP_TECHNOLOGY:
168 		val->intval = acpi_battery_technology(battery);
169 		break;
170 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
171 		val->intval = battery->design_voltage * 1000;
172 		break;
173 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
174 		val->intval = battery->voltage_now * 1000;
175 		break;
176 	case POWER_SUPPLY_PROP_CURRENT_NOW:
177 		val->intval = battery->current_now * 1000;
178 		break;
179 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
180 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
181 		val->intval = battery->design_capacity * 1000;
182 		break;
183 	case POWER_SUPPLY_PROP_CHARGE_FULL:
184 	case POWER_SUPPLY_PROP_ENERGY_FULL:
185 		val->intval = battery->full_charge_capacity * 1000;
186 		break;
187 	case POWER_SUPPLY_PROP_CHARGE_NOW:
188 	case POWER_SUPPLY_PROP_ENERGY_NOW:
189 		val->intval = battery->capacity_now * 1000;
190 		break;
191 	case POWER_SUPPLY_PROP_MODEL_NAME:
192 		val->strval = battery->model_number;
193 		break;
194 	case POWER_SUPPLY_PROP_MANUFACTURER:
195 		val->strval = battery->oem_info;
196 		break;
197 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
198 		val->strval = battery->serial_number;
199 		break;
200 	default:
201 		return -EINVAL;
202 	}
203 	return 0;
204 }
205 
206 static enum power_supply_property charge_battery_props[] = {
207 	POWER_SUPPLY_PROP_STATUS,
208 	POWER_SUPPLY_PROP_PRESENT,
209 	POWER_SUPPLY_PROP_TECHNOLOGY,
210 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
211 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
212 	POWER_SUPPLY_PROP_CURRENT_NOW,
213 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
214 	POWER_SUPPLY_PROP_CHARGE_FULL,
215 	POWER_SUPPLY_PROP_CHARGE_NOW,
216 	POWER_SUPPLY_PROP_MODEL_NAME,
217 	POWER_SUPPLY_PROP_MANUFACTURER,
218 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
219 };
220 
221 static enum power_supply_property energy_battery_props[] = {
222 	POWER_SUPPLY_PROP_STATUS,
223 	POWER_SUPPLY_PROP_PRESENT,
224 	POWER_SUPPLY_PROP_TECHNOLOGY,
225 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
226 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
227 	POWER_SUPPLY_PROP_CURRENT_NOW,
228 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
229 	POWER_SUPPLY_PROP_ENERGY_FULL,
230 	POWER_SUPPLY_PROP_ENERGY_NOW,
231 	POWER_SUPPLY_PROP_MODEL_NAME,
232 	POWER_SUPPLY_PROP_MANUFACTURER,
233 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
234 };
235 #endif
236 
237 #ifdef CONFIG_ACPI_PROCFS_POWER
238 inline char *acpi_battery_units(struct acpi_battery *battery)
239 {
240 	return (battery->power_unit)?"mA":"mW";
241 }
242 #endif
243 
244 /* --------------------------------------------------------------------------
245                                Battery Management
246    -------------------------------------------------------------------------- */
247 struct acpi_offsets {
248 	size_t offset;		/* offset inside struct acpi_sbs_battery */
249 	u8 mode;		/* int or string? */
250 };
251 
252 static struct acpi_offsets state_offsets[] = {
253 	{offsetof(struct acpi_battery, state), 0},
254 	{offsetof(struct acpi_battery, current_now), 0},
255 	{offsetof(struct acpi_battery, capacity_now), 0},
256 	{offsetof(struct acpi_battery, voltage_now), 0},
257 };
258 
259 static struct acpi_offsets info_offsets[] = {
260 	{offsetof(struct acpi_battery, power_unit), 0},
261 	{offsetof(struct acpi_battery, design_capacity), 0},
262 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
263 	{offsetof(struct acpi_battery, technology), 0},
264 	{offsetof(struct acpi_battery, design_voltage), 0},
265 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
266 	{offsetof(struct acpi_battery, design_capacity_low), 0},
267 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
268 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
269 	{offsetof(struct acpi_battery, model_number), 1},
270 	{offsetof(struct acpi_battery, serial_number), 1},
271 	{offsetof(struct acpi_battery, type), 1},
272 	{offsetof(struct acpi_battery, oem_info), 1},
273 };
274 
275 static int extract_package(struct acpi_battery *battery,
276 			   union acpi_object *package,
277 			   struct acpi_offsets *offsets, int num)
278 {
279 	int i;
280 	union acpi_object *element;
281 	if (package->type != ACPI_TYPE_PACKAGE)
282 		return -EFAULT;
283 	for (i = 0; i < num; ++i) {
284 		if (package->package.count <= i)
285 			return -EFAULT;
286 		element = &package->package.elements[i];
287 		if (offsets[i].mode) {
288 			u8 *ptr = (u8 *)battery + offsets[i].offset;
289 			if (element->type == ACPI_TYPE_STRING ||
290 			    element->type == ACPI_TYPE_BUFFER)
291 				strncpy(ptr, element->string.pointer, 32);
292 			else if (element->type == ACPI_TYPE_INTEGER) {
293 				strncpy(ptr, (u8 *)&element->integer.value,
294 					sizeof(acpi_integer));
295 				ptr[sizeof(acpi_integer)] = 0;
296 			} else return -EFAULT;
297 		} else {
298 			if (element->type == ACPI_TYPE_INTEGER) {
299 				int *x = (int *)((u8 *)battery +
300 						offsets[i].offset);
301 				*x = element->integer.value;
302 			} else return -EFAULT;
303 		}
304 	}
305 	return 0;
306 }
307 
308 static int acpi_battery_get_status(struct acpi_battery *battery)
309 {
310 	if (acpi_bus_get_status(battery->device)) {
311 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
312 		return -ENODEV;
313 	}
314 	return 0;
315 }
316 
317 static int acpi_battery_get_info(struct acpi_battery *battery)
318 {
319 	int result = -EFAULT;
320 	acpi_status status = 0;
321 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
322 
323 	if (!acpi_battery_present(battery))
324 		return 0;
325 	mutex_lock(&battery->lock);
326 	status = acpi_evaluate_object(battery->device->handle, "_BIF",
327 				      NULL, &buffer);
328 	mutex_unlock(&battery->lock);
329 
330 	if (ACPI_FAILURE(status)) {
331 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
332 		return -ENODEV;
333 	}
334 
335 	result = extract_package(battery, buffer.pointer,
336 				 info_offsets, ARRAY_SIZE(info_offsets));
337 	kfree(buffer.pointer);
338 	return result;
339 }
340 
341 static int acpi_battery_get_state(struct acpi_battery *battery)
342 {
343 	int result = 0;
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 
350 	if (battery->update_time &&
351 	    time_before(jiffies, battery->update_time +
352 			msecs_to_jiffies(cache_time)))
353 		return 0;
354 
355 	mutex_lock(&battery->lock);
356 	status = acpi_evaluate_object(battery->device->handle, "_BST",
357 				      NULL, &buffer);
358 	mutex_unlock(&battery->lock);
359 
360 	if (ACPI_FAILURE(status)) {
361 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
362 		return -ENODEV;
363 	}
364 
365 	result = extract_package(battery, buffer.pointer,
366 				 state_offsets, ARRAY_SIZE(state_offsets));
367 	battery->update_time = jiffies;
368 	kfree(buffer.pointer);
369 	return result;
370 }
371 
372 static int acpi_battery_set_alarm(struct acpi_battery *battery)
373 {
374 	acpi_status status = 0;
375 	union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
376 	struct acpi_object_list arg_list = { 1, &arg0 };
377 
378 	if (!acpi_battery_present(battery)|| !battery->alarm_present)
379 		return -ENODEV;
380 
381 	arg0.integer.value = battery->alarm;
382 
383 	mutex_lock(&battery->lock);
384 	status = acpi_evaluate_object(battery->device->handle, "_BTP",
385 				 &arg_list, NULL);
386 	mutex_unlock(&battery->lock);
387 
388 	if (ACPI_FAILURE(status))
389 		return -ENODEV;
390 
391 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
392 	return 0;
393 }
394 
395 static int acpi_battery_init_alarm(struct acpi_battery *battery)
396 {
397 	acpi_status status = AE_OK;
398 	acpi_handle handle = NULL;
399 
400 	/* See if alarms are supported, and if so, set default */
401 	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
402 	if (ACPI_FAILURE(status)) {
403 		battery->alarm_present = 0;
404 		return 0;
405 	}
406 	battery->alarm_present = 1;
407 	if (!battery->alarm)
408 		battery->alarm = battery->design_capacity_warning;
409 	return acpi_battery_set_alarm(battery);
410 }
411 
412 #ifdef CONFIG_ACPI_SYSFS_POWER
413 static ssize_t acpi_battery_alarm_show(struct device *dev,
414 					struct device_attribute *attr,
415 					char *buf)
416 {
417 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
418 	return sprintf(buf, "%d\n", battery->alarm * 1000);
419 }
420 
421 static ssize_t acpi_battery_alarm_store(struct device *dev,
422 					struct device_attribute *attr,
423 					const char *buf, size_t count)
424 {
425 	unsigned long x;
426 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
427 	if (sscanf(buf, "%ld\n", &x) == 1)
428 		battery->alarm = x/1000;
429 	if (acpi_battery_present(battery))
430 		acpi_battery_set_alarm(battery);
431 	return count;
432 }
433 
434 static struct device_attribute alarm_attr = {
435 	.attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE},
436 	.show = acpi_battery_alarm_show,
437 	.store = acpi_battery_alarm_store,
438 };
439 
440 static int sysfs_add_battery(struct acpi_battery *battery)
441 {
442 	int result;
443 
444 	if (battery->power_unit) {
445 		battery->bat.properties = charge_battery_props;
446 		battery->bat.num_properties =
447 			ARRAY_SIZE(charge_battery_props);
448 	} else {
449 		battery->bat.properties = energy_battery_props;
450 		battery->bat.num_properties =
451 			ARRAY_SIZE(energy_battery_props);
452 	}
453 
454 	battery->bat.name = acpi_device_bid(battery->device);
455 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
456 	battery->bat.get_property = acpi_battery_get_property;
457 
458 	result = power_supply_register(&battery->device->dev, &battery->bat);
459 	if (result)
460 		return result;
461 	return device_create_file(battery->bat.dev, &alarm_attr);
462 }
463 
464 static void sysfs_remove_battery(struct acpi_battery *battery)
465 {
466 	if (!battery->bat.dev)
467 		return;
468 	device_remove_file(battery->bat.dev, &alarm_attr);
469 	power_supply_unregister(&battery->bat);
470 	battery->bat.dev = NULL;
471 }
472 #endif
473 
474 static int acpi_battery_update(struct acpi_battery *battery)
475 {
476 	int result;
477 	result = acpi_battery_get_status(battery);
478 	if (result)
479 		return result;
480 #ifdef CONFIG_ACPI_SYSFS_POWER
481 	if (!acpi_battery_present(battery)) {
482 		sysfs_remove_battery(battery);
483 		battery->update_time = 0;
484 		return 0;
485 	}
486 #endif
487 	if (!battery->update_time) {
488 		result = acpi_battery_get_info(battery);
489 		if (result)
490 			return result;
491 		acpi_battery_init_alarm(battery);
492 	}
493 #ifdef CONFIG_ACPI_SYSFS_POWER
494 	if (!battery->bat.dev)
495 		sysfs_add_battery(battery);
496 #endif
497 	return acpi_battery_get_state(battery);
498 }
499 
500 /* --------------------------------------------------------------------------
501                               FS Interface (/proc)
502    -------------------------------------------------------------------------- */
503 
504 #ifdef CONFIG_ACPI_PROCFS_POWER
505 static struct proc_dir_entry *acpi_battery_dir;
506 
507 static int acpi_battery_print_info(struct seq_file *seq, int result)
508 {
509 	struct acpi_battery *battery = seq->private;
510 
511 	if (result)
512 		goto end;
513 
514 	seq_printf(seq, "present:                 %s\n",
515 		   acpi_battery_present(battery)?"yes":"no");
516 	if (!acpi_battery_present(battery))
517 		goto end;
518 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
519 		seq_printf(seq, "design capacity:         unknown\n");
520 	else
521 		seq_printf(seq, "design capacity:         %d %sh\n",
522 			   battery->design_capacity,
523 			   acpi_battery_units(battery));
524 
525 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
526 		seq_printf(seq, "last full capacity:      unknown\n");
527 	else
528 		seq_printf(seq, "last full capacity:      %d %sh\n",
529 			   battery->full_charge_capacity,
530 			   acpi_battery_units(battery));
531 
532 	seq_printf(seq, "battery technology:      %srechargeable\n",
533 		   (!battery->technology)?"non-":"");
534 
535 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
536 		seq_printf(seq, "design voltage:          unknown\n");
537 	else
538 		seq_printf(seq, "design voltage:          %d mV\n",
539 			   battery->design_voltage);
540 	seq_printf(seq, "design capacity warning: %d %sh\n",
541 		   battery->design_capacity_warning,
542 		   acpi_battery_units(battery));
543 	seq_printf(seq, "design capacity low:     %d %sh\n",
544 		   battery->design_capacity_low,
545 		   acpi_battery_units(battery));
546 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
547 		   battery->capacity_granularity_1,
548 		   acpi_battery_units(battery));
549 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
550 		   battery->capacity_granularity_2,
551 		   acpi_battery_units(battery));
552 	seq_printf(seq, "model number:            %s\n", battery->model_number);
553 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
554 	seq_printf(seq, "battery type:            %s\n", battery->type);
555 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
556       end:
557 	if (result)
558 		seq_printf(seq, "ERROR: Unable to read battery info\n");
559 	return result;
560 }
561 
562 static int acpi_battery_print_state(struct seq_file *seq, int result)
563 {
564 	struct acpi_battery *battery = seq->private;
565 
566 	if (result)
567 		goto end;
568 
569 	seq_printf(seq, "present:                 %s\n",
570 		   acpi_battery_present(battery)?"yes":"no");
571 	if (!acpi_battery_present(battery))
572 		goto end;
573 
574 	seq_printf(seq, "capacity state:          %s\n",
575 			(battery->state & 0x04)?"critical":"ok");
576 	if ((battery->state & 0x01) && (battery->state & 0x02))
577 		seq_printf(seq,
578 			   "charging state:          charging/discharging\n");
579 	else if (battery->state & 0x01)
580 		seq_printf(seq, "charging state:          discharging\n");
581 	else if (battery->state & 0x02)
582 		seq_printf(seq, "charging state:          charging\n");
583 	else
584 		seq_printf(seq, "charging state:          charged\n");
585 
586 	if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
587 		seq_printf(seq, "present rate:            unknown\n");
588 	else
589 		seq_printf(seq, "present rate:            %d %s\n",
590 			   battery->current_now, acpi_battery_units(battery));
591 
592 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
593 		seq_printf(seq, "remaining capacity:      unknown\n");
594 	else
595 		seq_printf(seq, "remaining capacity:      %d %sh\n",
596 			   battery->capacity_now, acpi_battery_units(battery));
597 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
598 		seq_printf(seq, "present voltage:         unknown\n");
599 	else
600 		seq_printf(seq, "present voltage:         %d mV\n",
601 			   battery->voltage_now);
602       end:
603 	if (result)
604 		seq_printf(seq, "ERROR: Unable to read battery state\n");
605 
606 	return result;
607 }
608 
609 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
610 {
611 	struct acpi_battery *battery = seq->private;
612 
613 	if (result)
614 		goto end;
615 
616 	if (!acpi_battery_present(battery)) {
617 		seq_printf(seq, "present:                 no\n");
618 		goto end;
619 	}
620 	seq_printf(seq, "alarm:                   ");
621 	if (!battery->alarm)
622 		seq_printf(seq, "unsupported\n");
623 	else
624 		seq_printf(seq, "%u %sh\n", battery->alarm,
625 				acpi_battery_units(battery));
626       end:
627 	if (result)
628 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
629 	return result;
630 }
631 
632 static ssize_t acpi_battery_write_alarm(struct file *file,
633 					const char __user * buffer,
634 					size_t count, loff_t * ppos)
635 {
636 	int result = 0;
637 	char alarm_string[12] = { '\0' };
638 	struct seq_file *m = file->private_data;
639 	struct acpi_battery *battery = m->private;
640 
641 	if (!battery || (count > sizeof(alarm_string) - 1))
642 		return -EINVAL;
643 	if (!acpi_battery_present(battery)) {
644 		result = -ENODEV;
645 		goto end;
646 	}
647 	if (copy_from_user(alarm_string, buffer, count)) {
648 		result = -EFAULT;
649 		goto end;
650 	}
651 	alarm_string[count] = '\0';
652 	battery->alarm = simple_strtol(alarm_string, NULL, 0);
653 	result = acpi_battery_set_alarm(battery);
654       end:
655 	if (!result)
656 		return count;
657 	return result;
658 }
659 
660 typedef int(*print_func)(struct seq_file *seq, int result);
661 
662 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
663 	acpi_battery_print_info,
664 	acpi_battery_print_state,
665 	acpi_battery_print_alarm,
666 };
667 
668 static int acpi_battery_read(int fid, struct seq_file *seq)
669 {
670 	struct acpi_battery *battery = seq->private;
671 	int result = acpi_battery_update(battery);
672 	return acpi_print_funcs[fid](seq, result);
673 }
674 
675 #define DECLARE_FILE_FUNCTIONS(_name) \
676 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
677 { \
678 	return acpi_battery_read(_name##_tag, seq); \
679 } \
680 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
681 { \
682 	return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
683 }
684 
685 DECLARE_FILE_FUNCTIONS(info);
686 DECLARE_FILE_FUNCTIONS(state);
687 DECLARE_FILE_FUNCTIONS(alarm);
688 
689 #undef DECLARE_FILE_FUNCTIONS
690 
691 #define FILE_DESCRIPTION_RO(_name) \
692 	{ \
693 	.name = __stringify(_name), \
694 	.mode = S_IRUGO, \
695 	.ops = { \
696 		.open = acpi_battery_##_name##_open_fs, \
697 		.read = seq_read, \
698 		.llseek = seq_lseek, \
699 		.release = single_release, \
700 		.owner = THIS_MODULE, \
701 		}, \
702 	}
703 
704 #define FILE_DESCRIPTION_RW(_name) \
705 	{ \
706 	.name = __stringify(_name), \
707 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
708 	.ops = { \
709 		.open = acpi_battery_##_name##_open_fs, \
710 		.read = seq_read, \
711 		.llseek = seq_lseek, \
712 		.write = acpi_battery_write_##_name, \
713 		.release = single_release, \
714 		.owner = THIS_MODULE, \
715 		}, \
716 	}
717 
718 static struct battery_file {
719 	struct file_operations ops;
720 	mode_t mode;
721 	char *name;
722 } acpi_battery_file[] = {
723 	FILE_DESCRIPTION_RO(info),
724 	FILE_DESCRIPTION_RO(state),
725 	FILE_DESCRIPTION_RW(alarm),
726 };
727 
728 #undef FILE_DESCRIPTION_RO
729 #undef FILE_DESCRIPTION_RW
730 
731 static int acpi_battery_add_fs(struct acpi_device *device)
732 {
733 	struct proc_dir_entry *entry = NULL;
734 	int i;
735 
736 	if (!acpi_device_dir(device)) {
737 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
738 						     acpi_battery_dir);
739 		if (!acpi_device_dir(device))
740 			return -ENODEV;
741 		acpi_device_dir(device)->owner = THIS_MODULE;
742 	}
743 
744 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
745 		entry = create_proc_entry(acpi_battery_file[i].name,
746 				  acpi_battery_file[i].mode, acpi_device_dir(device));
747 		if (!entry)
748 			return -ENODEV;
749 		else {
750 			entry->proc_fops = &acpi_battery_file[i].ops;
751 			entry->data = acpi_driver_data(device);
752 			entry->owner = THIS_MODULE;
753 		}
754 	}
755 	return 0;
756 }
757 
758 static void acpi_battery_remove_fs(struct acpi_device *device)
759 {
760 	int i;
761 	if (!acpi_device_dir(device))
762 		return;
763 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
764 		remove_proc_entry(acpi_battery_file[i].name,
765 				  acpi_device_dir(device));
766 
767 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
768 	acpi_device_dir(device) = NULL;
769 }
770 
771 #endif
772 
773 /* --------------------------------------------------------------------------
774                                  Driver Interface
775    -------------------------------------------------------------------------- */
776 
777 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
778 {
779 	struct acpi_battery *battery = data;
780 	struct acpi_device *device;
781 	if (!battery)
782 		return;
783 	device = battery->device;
784 	acpi_battery_update(battery);
785 	acpi_bus_generate_proc_event(device, event,
786 				     acpi_battery_present(battery));
787 	acpi_bus_generate_netlink_event(device->pnp.device_class,
788 					device->dev.bus_id, event,
789 					acpi_battery_present(battery));
790 #ifdef CONFIG_ACPI_SYSFS_POWER
791 	/* acpi_batter_update could remove power_supply object */
792 	if (battery->bat.dev)
793 		kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
794 #endif
795 }
796 
797 static int acpi_battery_add(struct acpi_device *device)
798 {
799 	int result = 0;
800 	acpi_status status = 0;
801 	struct acpi_battery *battery = NULL;
802 	if (!device)
803 		return -EINVAL;
804 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
805 	if (!battery)
806 		return -ENOMEM;
807 	battery->device = device;
808 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
809 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
810 	acpi_driver_data(device) = battery;
811 	mutex_init(&battery->lock);
812 	acpi_battery_update(battery);
813 #ifdef CONFIG_ACPI_PROCFS_POWER
814 	result = acpi_battery_add_fs(device);
815 	if (result)
816 		goto end;
817 #endif
818 	status = acpi_install_notify_handler(device->handle,
819 					     ACPI_ALL_NOTIFY,
820 					     acpi_battery_notify, battery);
821 	if (ACPI_FAILURE(status)) {
822 		ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
823 		result = -ENODEV;
824 		goto end;
825 	}
826 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
827 	       ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
828 	       device->status.battery_present ? "present" : "absent");
829       end:
830 	if (result) {
831 #ifdef CONFIG_ACPI_PROCFS_POWER
832 		acpi_battery_remove_fs(device);
833 #endif
834 		kfree(battery);
835 	}
836 	return result;
837 }
838 
839 static int acpi_battery_remove(struct acpi_device *device, int type)
840 {
841 	acpi_status status = 0;
842 	struct acpi_battery *battery = NULL;
843 
844 	if (!device || !acpi_driver_data(device))
845 		return -EINVAL;
846 	battery = acpi_driver_data(device);
847 	status = acpi_remove_notify_handler(device->handle,
848 					    ACPI_ALL_NOTIFY,
849 					    acpi_battery_notify);
850 #ifdef CONFIG_ACPI_PROCFS_POWER
851 	acpi_battery_remove_fs(device);
852 #endif
853 #ifdef CONFIG_ACPI_SYSFS_POWER
854 	sysfs_remove_battery(battery);
855 #endif
856 	mutex_destroy(&battery->lock);
857 	kfree(battery);
858 	return 0;
859 }
860 
861 /* this is needed to learn about changes made in suspended state */
862 static int acpi_battery_resume(struct acpi_device *device)
863 {
864 	struct acpi_battery *battery;
865 	if (!device)
866 		return -EINVAL;
867 	battery = acpi_driver_data(device);
868 	battery->update_time = 0;
869 	acpi_battery_update(battery);
870 	return 0;
871 }
872 
873 static struct acpi_driver acpi_battery_driver = {
874 	.name = "battery",
875 	.class = ACPI_BATTERY_CLASS,
876 	.ids = battery_device_ids,
877 	.ops = {
878 		.add = acpi_battery_add,
879 		.resume = acpi_battery_resume,
880 		.remove = acpi_battery_remove,
881 		},
882 };
883 
884 static int __init acpi_battery_init(void)
885 {
886 	if (acpi_disabled)
887 		return -ENODEV;
888 #ifdef CONFIG_ACPI_PROCFS_POWER
889 	acpi_battery_dir = acpi_lock_battery_dir();
890 	if (!acpi_battery_dir)
891 		return -ENODEV;
892 #endif
893 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
894 #ifdef CONFIG_ACPI_PROCFS_POWER
895 		acpi_unlock_battery_dir(acpi_battery_dir);
896 #endif
897 		return -ENODEV;
898 	}
899 	return 0;
900 }
901 
902 static void __exit acpi_battery_exit(void)
903 {
904 	acpi_bus_unregister_driver(&acpi_battery_driver);
905 #ifdef CONFIG_ACPI_PROCFS_POWER
906 	acpi_unlock_battery_dir(acpi_battery_dir);
907 #endif
908 }
909 
910 module_init(acpi_battery_init);
911 module_exit(acpi_battery_exit);
912