xref: /openbmc/linux/drivers/acpi/battery.c (revision a09d2831)
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 #include <linux/dmi.h>
35 
36 #ifdef CONFIG_ACPI_PROCFS_POWER
37 #include <linux/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <asm/uaccess.h>
40 #endif
41 
42 #include <acpi/acpi_bus.h>
43 #include <acpi/acpi_drivers.h>
44 
45 #ifdef CONFIG_ACPI_SYSFS_POWER
46 #include <linux/power_supply.h>
47 #endif
48 
49 #define PREFIX "ACPI: "
50 
51 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
52 
53 #define ACPI_BATTERY_CLASS		"battery"
54 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
55 #define ACPI_BATTERY_NOTIFY_STATUS	0x80
56 #define ACPI_BATTERY_NOTIFY_INFO	0x81
57 
58 #define _COMPONENT		ACPI_BATTERY_COMPONENT
59 
60 ACPI_MODULE_NAME("battery");
61 
62 MODULE_AUTHOR("Paul Diefenbaugh");
63 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
64 MODULE_DESCRIPTION("ACPI Battery Driver");
65 MODULE_LICENSE("GPL");
66 
67 static unsigned int cache_time = 1000;
68 module_param(cache_time, uint, 0644);
69 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
70 
71 #ifdef CONFIG_ACPI_PROCFS_POWER
72 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
73 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
74 
75 enum acpi_battery_files {
76 	info_tag = 0,
77 	state_tag,
78 	alarm_tag,
79 	ACPI_BATTERY_NUMFILES,
80 };
81 
82 #endif
83 
84 static const struct acpi_device_id battery_device_ids[] = {
85 	{"PNP0C0A", 0},
86 	{"", 0},
87 };
88 
89 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
90 
91 /* For buggy DSDTs that report negative 16-bit values for either charging
92  * or discharging current and/or report 0 as 65536 due to bad math.
93  */
94 #define QUIRK_SIGNED16_CURRENT 0x0001
95 
96 struct acpi_battery {
97 	struct mutex lock;
98 #ifdef CONFIG_ACPI_SYSFS_POWER
99 	struct power_supply bat;
100 #endif
101 	struct acpi_device *device;
102 	unsigned long update_time;
103 	int rate_now;
104 	int capacity_now;
105 	int voltage_now;
106 	int design_capacity;
107 	int full_charge_capacity;
108 	int technology;
109 	int design_voltage;
110 	int design_capacity_warning;
111 	int design_capacity_low;
112 	int capacity_granularity_1;
113 	int capacity_granularity_2;
114 	int alarm;
115 	char model_number[32];
116 	char serial_number[32];
117 	char type[32];
118 	char oem_info[32];
119 	int state;
120 	int power_unit;
121 	u8 alarm_present;
122 	long quirks;
123 };
124 
125 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
126 
127 inline int acpi_battery_present(struct acpi_battery *battery)
128 {
129 	return battery->device->status.battery_present;
130 }
131 
132 #ifdef CONFIG_ACPI_SYSFS_POWER
133 static int acpi_battery_technology(struct acpi_battery *battery)
134 {
135 	if (!strcasecmp("NiCd", battery->type))
136 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
137 	if (!strcasecmp("NiMH", battery->type))
138 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
139 	if (!strcasecmp("LION", battery->type))
140 		return POWER_SUPPLY_TECHNOLOGY_LION;
141 	if (!strncasecmp("LI-ION", battery->type, 6))
142 		return POWER_SUPPLY_TECHNOLOGY_LION;
143 	if (!strcasecmp("LiP", battery->type))
144 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
145 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
146 }
147 
148 static int acpi_battery_get_state(struct acpi_battery *battery);
149 
150 static int acpi_battery_is_charged(struct acpi_battery *battery)
151 {
152 	/* either charging or discharging */
153 	if (battery->state != 0)
154 		return 0;
155 
156 	/* battery not reporting charge */
157 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
158 	    battery->capacity_now == 0)
159 		return 0;
160 
161 	/* good batteries update full_charge as the batteries degrade */
162 	if (battery->full_charge_capacity == battery->capacity_now)
163 		return 1;
164 
165 	/* fallback to using design values for broken batteries */
166 	if (battery->design_capacity == battery->capacity_now)
167 		return 1;
168 
169 	/* we don't do any sort of metric based on percentages */
170 	return 0;
171 }
172 
173 static int acpi_battery_get_property(struct power_supply *psy,
174 				     enum power_supply_property psp,
175 				     union power_supply_propval *val)
176 {
177 	struct acpi_battery *battery = to_acpi_battery(psy);
178 
179 	if (acpi_battery_present(battery)) {
180 		/* run battery update only if it is present */
181 		acpi_battery_get_state(battery);
182 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
183 		return -ENODEV;
184 	switch (psp) {
185 	case POWER_SUPPLY_PROP_STATUS:
186 		if (battery->state & 0x01)
187 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
188 		else if (battery->state & 0x02)
189 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
190 		else if (acpi_battery_is_charged(battery))
191 			val->intval = POWER_SUPPLY_STATUS_FULL;
192 		else
193 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
194 		break;
195 	case POWER_SUPPLY_PROP_PRESENT:
196 		val->intval = acpi_battery_present(battery);
197 		break;
198 	case POWER_SUPPLY_PROP_TECHNOLOGY:
199 		val->intval = acpi_battery_technology(battery);
200 		break;
201 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
202 		val->intval = battery->design_voltage * 1000;
203 		break;
204 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
205 		val->intval = battery->voltage_now * 1000;
206 		break;
207 	case POWER_SUPPLY_PROP_CURRENT_NOW:
208 	case POWER_SUPPLY_PROP_POWER_NOW:
209 		val->intval = battery->rate_now * 1000;
210 		break;
211 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
212 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
213 		val->intval = battery->design_capacity * 1000;
214 		break;
215 	case POWER_SUPPLY_PROP_CHARGE_FULL:
216 	case POWER_SUPPLY_PROP_ENERGY_FULL:
217 		val->intval = battery->full_charge_capacity * 1000;
218 		break;
219 	case POWER_SUPPLY_PROP_CHARGE_NOW:
220 	case POWER_SUPPLY_PROP_ENERGY_NOW:
221 		val->intval = battery->capacity_now * 1000;
222 		break;
223 	case POWER_SUPPLY_PROP_MODEL_NAME:
224 		val->strval = battery->model_number;
225 		break;
226 	case POWER_SUPPLY_PROP_MANUFACTURER:
227 		val->strval = battery->oem_info;
228 		break;
229 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
230 		val->strval = battery->serial_number;
231 		break;
232 	default:
233 		return -EINVAL;
234 	}
235 	return 0;
236 }
237 
238 static enum power_supply_property charge_battery_props[] = {
239 	POWER_SUPPLY_PROP_STATUS,
240 	POWER_SUPPLY_PROP_PRESENT,
241 	POWER_SUPPLY_PROP_TECHNOLOGY,
242 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
243 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
244 	POWER_SUPPLY_PROP_CURRENT_NOW,
245 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
246 	POWER_SUPPLY_PROP_CHARGE_FULL,
247 	POWER_SUPPLY_PROP_CHARGE_NOW,
248 	POWER_SUPPLY_PROP_MODEL_NAME,
249 	POWER_SUPPLY_PROP_MANUFACTURER,
250 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
251 };
252 
253 static enum power_supply_property energy_battery_props[] = {
254 	POWER_SUPPLY_PROP_STATUS,
255 	POWER_SUPPLY_PROP_PRESENT,
256 	POWER_SUPPLY_PROP_TECHNOLOGY,
257 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
258 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
259 	POWER_SUPPLY_PROP_CURRENT_NOW,
260 	POWER_SUPPLY_PROP_POWER_NOW,
261 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
262 	POWER_SUPPLY_PROP_ENERGY_FULL,
263 	POWER_SUPPLY_PROP_ENERGY_NOW,
264 	POWER_SUPPLY_PROP_MODEL_NAME,
265 	POWER_SUPPLY_PROP_MANUFACTURER,
266 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
267 };
268 #endif
269 
270 #ifdef CONFIG_ACPI_PROCFS_POWER
271 inline char *acpi_battery_units(struct acpi_battery *battery)
272 {
273 	return (battery->power_unit)?"mA":"mW";
274 }
275 #endif
276 
277 /* --------------------------------------------------------------------------
278                                Battery Management
279    -------------------------------------------------------------------------- */
280 struct acpi_offsets {
281 	size_t offset;		/* offset inside struct acpi_sbs_battery */
282 	u8 mode;		/* int or string? */
283 };
284 
285 static struct acpi_offsets state_offsets[] = {
286 	{offsetof(struct acpi_battery, state), 0},
287 	{offsetof(struct acpi_battery, rate_now), 0},
288 	{offsetof(struct acpi_battery, capacity_now), 0},
289 	{offsetof(struct acpi_battery, voltage_now), 0},
290 };
291 
292 static struct acpi_offsets info_offsets[] = {
293 	{offsetof(struct acpi_battery, power_unit), 0},
294 	{offsetof(struct acpi_battery, design_capacity), 0},
295 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
296 	{offsetof(struct acpi_battery, technology), 0},
297 	{offsetof(struct acpi_battery, design_voltage), 0},
298 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
299 	{offsetof(struct acpi_battery, design_capacity_low), 0},
300 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
301 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
302 	{offsetof(struct acpi_battery, model_number), 1},
303 	{offsetof(struct acpi_battery, serial_number), 1},
304 	{offsetof(struct acpi_battery, type), 1},
305 	{offsetof(struct acpi_battery, oem_info), 1},
306 };
307 
308 static int extract_package(struct acpi_battery *battery,
309 			   union acpi_object *package,
310 			   struct acpi_offsets *offsets, int num)
311 {
312 	int i;
313 	union acpi_object *element;
314 	if (package->type != ACPI_TYPE_PACKAGE)
315 		return -EFAULT;
316 	for (i = 0; i < num; ++i) {
317 		if (package->package.count <= i)
318 			return -EFAULT;
319 		element = &package->package.elements[i];
320 		if (offsets[i].mode) {
321 			u8 *ptr = (u8 *)battery + offsets[i].offset;
322 			if (element->type == ACPI_TYPE_STRING ||
323 			    element->type == ACPI_TYPE_BUFFER)
324 				strncpy(ptr, element->string.pointer, 32);
325 			else if (element->type == ACPI_TYPE_INTEGER) {
326 				strncpy(ptr, (u8 *)&element->integer.value,
327 					sizeof(acpi_integer));
328 				ptr[sizeof(acpi_integer)] = 0;
329 			} else
330 				*ptr = 0; /* don't have value */
331 		} else {
332 			int *x = (int *)((u8 *)battery + offsets[i].offset);
333 			*x = (element->type == ACPI_TYPE_INTEGER) ?
334 				element->integer.value : -1;
335 		}
336 	}
337 	return 0;
338 }
339 
340 static int acpi_battery_get_status(struct acpi_battery *battery)
341 {
342 	if (acpi_bus_get_status(battery->device)) {
343 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
344 		return -ENODEV;
345 	}
346 	return 0;
347 }
348 
349 static int acpi_battery_get_info(struct acpi_battery *battery)
350 {
351 	int result = -EFAULT;
352 	acpi_status status = 0;
353 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
354 
355 	if (!acpi_battery_present(battery))
356 		return 0;
357 	mutex_lock(&battery->lock);
358 	status = acpi_evaluate_object(battery->device->handle, "_BIF",
359 				      NULL, &buffer);
360 	mutex_unlock(&battery->lock);
361 
362 	if (ACPI_FAILURE(status)) {
363 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
364 		return -ENODEV;
365 	}
366 
367 	result = extract_package(battery, buffer.pointer,
368 				 info_offsets, ARRAY_SIZE(info_offsets));
369 	kfree(buffer.pointer);
370 	return result;
371 }
372 
373 static int acpi_battery_get_state(struct acpi_battery *battery)
374 {
375 	int result = 0;
376 	acpi_status status = 0;
377 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
378 
379 	if (!acpi_battery_present(battery))
380 		return 0;
381 
382 	if (battery->update_time &&
383 	    time_before(jiffies, battery->update_time +
384 			msecs_to_jiffies(cache_time)))
385 		return 0;
386 
387 	mutex_lock(&battery->lock);
388 	status = acpi_evaluate_object(battery->device->handle, "_BST",
389 				      NULL, &buffer);
390 	mutex_unlock(&battery->lock);
391 
392 	if (ACPI_FAILURE(status)) {
393 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
394 		return -ENODEV;
395 	}
396 
397 	result = extract_package(battery, buffer.pointer,
398 				 state_offsets, ARRAY_SIZE(state_offsets));
399 	battery->update_time = jiffies;
400 	kfree(buffer.pointer);
401 
402 	if ((battery->quirks & QUIRK_SIGNED16_CURRENT) &&
403 	    battery->rate_now != -1)
404 		battery->rate_now = abs((s16)battery->rate_now);
405 
406 	return result;
407 }
408 
409 static int acpi_battery_set_alarm(struct acpi_battery *battery)
410 {
411 	acpi_status status = 0;
412 	union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
413 	struct acpi_object_list arg_list = { 1, &arg0 };
414 
415 	if (!acpi_battery_present(battery)|| !battery->alarm_present)
416 		return -ENODEV;
417 
418 	arg0.integer.value = battery->alarm;
419 
420 	mutex_lock(&battery->lock);
421 	status = acpi_evaluate_object(battery->device->handle, "_BTP",
422 				 &arg_list, NULL);
423 	mutex_unlock(&battery->lock);
424 
425 	if (ACPI_FAILURE(status))
426 		return -ENODEV;
427 
428 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
429 	return 0;
430 }
431 
432 static int acpi_battery_init_alarm(struct acpi_battery *battery)
433 {
434 	acpi_status status = AE_OK;
435 	acpi_handle handle = NULL;
436 
437 	/* See if alarms are supported, and if so, set default */
438 	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
439 	if (ACPI_FAILURE(status)) {
440 		battery->alarm_present = 0;
441 		return 0;
442 	}
443 	battery->alarm_present = 1;
444 	if (!battery->alarm)
445 		battery->alarm = battery->design_capacity_warning;
446 	return acpi_battery_set_alarm(battery);
447 }
448 
449 #ifdef CONFIG_ACPI_SYSFS_POWER
450 static ssize_t acpi_battery_alarm_show(struct device *dev,
451 					struct device_attribute *attr,
452 					char *buf)
453 {
454 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
455 	return sprintf(buf, "%d\n", battery->alarm * 1000);
456 }
457 
458 static ssize_t acpi_battery_alarm_store(struct device *dev,
459 					struct device_attribute *attr,
460 					const char *buf, size_t count)
461 {
462 	unsigned long x;
463 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
464 	if (sscanf(buf, "%ld\n", &x) == 1)
465 		battery->alarm = x/1000;
466 	if (acpi_battery_present(battery))
467 		acpi_battery_set_alarm(battery);
468 	return count;
469 }
470 
471 static struct device_attribute alarm_attr = {
472 	.attr = {.name = "alarm", .mode = 0644},
473 	.show = acpi_battery_alarm_show,
474 	.store = acpi_battery_alarm_store,
475 };
476 
477 static int sysfs_add_battery(struct acpi_battery *battery)
478 {
479 	int result;
480 
481 	if (battery->power_unit) {
482 		battery->bat.properties = charge_battery_props;
483 		battery->bat.num_properties =
484 			ARRAY_SIZE(charge_battery_props);
485 	} else {
486 		battery->bat.properties = energy_battery_props;
487 		battery->bat.num_properties =
488 			ARRAY_SIZE(energy_battery_props);
489 	}
490 
491 	battery->bat.name = acpi_device_bid(battery->device);
492 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
493 	battery->bat.get_property = acpi_battery_get_property;
494 
495 	result = power_supply_register(&battery->device->dev, &battery->bat);
496 	if (result)
497 		return result;
498 	return device_create_file(battery->bat.dev, &alarm_attr);
499 }
500 
501 static void sysfs_remove_battery(struct acpi_battery *battery)
502 {
503 	if (!battery->bat.dev)
504 		return;
505 	device_remove_file(battery->bat.dev, &alarm_attr);
506 	power_supply_unregister(&battery->bat);
507 	battery->bat.dev = NULL;
508 }
509 #endif
510 
511 static void acpi_battery_quirks(struct acpi_battery *battery)
512 {
513 	battery->quirks = 0;
514 	if (dmi_name_in_vendors("Acer") && battery->power_unit) {
515 		battery->quirks |= QUIRK_SIGNED16_CURRENT;
516 	}
517 }
518 
519 static int acpi_battery_update(struct acpi_battery *battery)
520 {
521 	int result, old_present = acpi_battery_present(battery);
522 	result = acpi_battery_get_status(battery);
523 	if (result)
524 		return result;
525 #ifdef CONFIG_ACPI_SYSFS_POWER
526 	if (!acpi_battery_present(battery)) {
527 		sysfs_remove_battery(battery);
528 		battery->update_time = 0;
529 		return 0;
530 	}
531 #endif
532 	if (!battery->update_time ||
533 	    old_present != acpi_battery_present(battery)) {
534 		result = acpi_battery_get_info(battery);
535 		if (result)
536 			return result;
537 		acpi_battery_quirks(battery);
538 		acpi_battery_init_alarm(battery);
539 	}
540 #ifdef CONFIG_ACPI_SYSFS_POWER
541 	if (!battery->bat.dev)
542 		sysfs_add_battery(battery);
543 #endif
544 	return acpi_battery_get_state(battery);
545 }
546 
547 /* --------------------------------------------------------------------------
548                               FS Interface (/proc)
549    -------------------------------------------------------------------------- */
550 
551 #ifdef CONFIG_ACPI_PROCFS_POWER
552 static struct proc_dir_entry *acpi_battery_dir;
553 
554 static int acpi_battery_print_info(struct seq_file *seq, int result)
555 {
556 	struct acpi_battery *battery = seq->private;
557 
558 	if (result)
559 		goto end;
560 
561 	seq_printf(seq, "present:                 %s\n",
562 		   acpi_battery_present(battery)?"yes":"no");
563 	if (!acpi_battery_present(battery))
564 		goto end;
565 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
566 		seq_printf(seq, "design capacity:         unknown\n");
567 	else
568 		seq_printf(seq, "design capacity:         %d %sh\n",
569 			   battery->design_capacity,
570 			   acpi_battery_units(battery));
571 
572 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
573 		seq_printf(seq, "last full capacity:      unknown\n");
574 	else
575 		seq_printf(seq, "last full capacity:      %d %sh\n",
576 			   battery->full_charge_capacity,
577 			   acpi_battery_units(battery));
578 
579 	seq_printf(seq, "battery technology:      %srechargeable\n",
580 		   (!battery->technology)?"non-":"");
581 
582 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
583 		seq_printf(seq, "design voltage:          unknown\n");
584 	else
585 		seq_printf(seq, "design voltage:          %d mV\n",
586 			   battery->design_voltage);
587 	seq_printf(seq, "design capacity warning: %d %sh\n",
588 		   battery->design_capacity_warning,
589 		   acpi_battery_units(battery));
590 	seq_printf(seq, "design capacity low:     %d %sh\n",
591 		   battery->design_capacity_low,
592 		   acpi_battery_units(battery));
593 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
594 		   battery->capacity_granularity_1,
595 		   acpi_battery_units(battery));
596 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
597 		   battery->capacity_granularity_2,
598 		   acpi_battery_units(battery));
599 	seq_printf(seq, "model number:            %s\n", battery->model_number);
600 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
601 	seq_printf(seq, "battery type:            %s\n", battery->type);
602 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
603       end:
604 	if (result)
605 		seq_printf(seq, "ERROR: Unable to read battery info\n");
606 	return result;
607 }
608 
609 static int acpi_battery_print_state(struct seq_file *seq, int result)
610 {
611 	struct acpi_battery *battery = seq->private;
612 
613 	if (result)
614 		goto end;
615 
616 	seq_printf(seq, "present:                 %s\n",
617 		   acpi_battery_present(battery)?"yes":"no");
618 	if (!acpi_battery_present(battery))
619 		goto end;
620 
621 	seq_printf(seq, "capacity state:          %s\n",
622 			(battery->state & 0x04)?"critical":"ok");
623 	if ((battery->state & 0x01) && (battery->state & 0x02))
624 		seq_printf(seq,
625 			   "charging state:          charging/discharging\n");
626 	else if (battery->state & 0x01)
627 		seq_printf(seq, "charging state:          discharging\n");
628 	else if (battery->state & 0x02)
629 		seq_printf(seq, "charging state:          charging\n");
630 	else
631 		seq_printf(seq, "charging state:          charged\n");
632 
633 	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
634 		seq_printf(seq, "present rate:            unknown\n");
635 	else
636 		seq_printf(seq, "present rate:            %d %s\n",
637 			   battery->rate_now, acpi_battery_units(battery));
638 
639 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
640 		seq_printf(seq, "remaining capacity:      unknown\n");
641 	else
642 		seq_printf(seq, "remaining capacity:      %d %sh\n",
643 			   battery->capacity_now, acpi_battery_units(battery));
644 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
645 		seq_printf(seq, "present voltage:         unknown\n");
646 	else
647 		seq_printf(seq, "present voltage:         %d mV\n",
648 			   battery->voltage_now);
649       end:
650 	if (result)
651 		seq_printf(seq, "ERROR: Unable to read battery state\n");
652 
653 	return result;
654 }
655 
656 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
657 {
658 	struct acpi_battery *battery = seq->private;
659 
660 	if (result)
661 		goto end;
662 
663 	if (!acpi_battery_present(battery)) {
664 		seq_printf(seq, "present:                 no\n");
665 		goto end;
666 	}
667 	seq_printf(seq, "alarm:                   ");
668 	if (!battery->alarm)
669 		seq_printf(seq, "unsupported\n");
670 	else
671 		seq_printf(seq, "%u %sh\n", battery->alarm,
672 				acpi_battery_units(battery));
673       end:
674 	if (result)
675 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
676 	return result;
677 }
678 
679 static ssize_t acpi_battery_write_alarm(struct file *file,
680 					const char __user * buffer,
681 					size_t count, loff_t * ppos)
682 {
683 	int result = 0;
684 	char alarm_string[12] = { '\0' };
685 	struct seq_file *m = file->private_data;
686 	struct acpi_battery *battery = m->private;
687 
688 	if (!battery || (count > sizeof(alarm_string) - 1))
689 		return -EINVAL;
690 	if (!acpi_battery_present(battery)) {
691 		result = -ENODEV;
692 		goto end;
693 	}
694 	if (copy_from_user(alarm_string, buffer, count)) {
695 		result = -EFAULT;
696 		goto end;
697 	}
698 	alarm_string[count] = '\0';
699 	battery->alarm = simple_strtol(alarm_string, NULL, 0);
700 	result = acpi_battery_set_alarm(battery);
701       end:
702 	if (!result)
703 		return count;
704 	return result;
705 }
706 
707 typedef int(*print_func)(struct seq_file *seq, int result);
708 
709 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
710 	acpi_battery_print_info,
711 	acpi_battery_print_state,
712 	acpi_battery_print_alarm,
713 };
714 
715 static int acpi_battery_read(int fid, struct seq_file *seq)
716 {
717 	struct acpi_battery *battery = seq->private;
718 	int result = acpi_battery_update(battery);
719 	return acpi_print_funcs[fid](seq, result);
720 }
721 
722 #define DECLARE_FILE_FUNCTIONS(_name) \
723 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
724 { \
725 	return acpi_battery_read(_name##_tag, seq); \
726 } \
727 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
728 { \
729 	return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
730 }
731 
732 DECLARE_FILE_FUNCTIONS(info);
733 DECLARE_FILE_FUNCTIONS(state);
734 DECLARE_FILE_FUNCTIONS(alarm);
735 
736 #undef DECLARE_FILE_FUNCTIONS
737 
738 #define FILE_DESCRIPTION_RO(_name) \
739 	{ \
740 	.name = __stringify(_name), \
741 	.mode = S_IRUGO, \
742 	.ops = { \
743 		.open = acpi_battery_##_name##_open_fs, \
744 		.read = seq_read, \
745 		.llseek = seq_lseek, \
746 		.release = single_release, \
747 		.owner = THIS_MODULE, \
748 		}, \
749 	}
750 
751 #define FILE_DESCRIPTION_RW(_name) \
752 	{ \
753 	.name = __stringify(_name), \
754 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
755 	.ops = { \
756 		.open = acpi_battery_##_name##_open_fs, \
757 		.read = seq_read, \
758 		.llseek = seq_lseek, \
759 		.write = acpi_battery_write_##_name, \
760 		.release = single_release, \
761 		.owner = THIS_MODULE, \
762 		}, \
763 	}
764 
765 static struct battery_file {
766 	struct file_operations ops;
767 	mode_t mode;
768 	const char *name;
769 } acpi_battery_file[] = {
770 	FILE_DESCRIPTION_RO(info),
771 	FILE_DESCRIPTION_RO(state),
772 	FILE_DESCRIPTION_RW(alarm),
773 };
774 
775 #undef FILE_DESCRIPTION_RO
776 #undef FILE_DESCRIPTION_RW
777 
778 static int acpi_battery_add_fs(struct acpi_device *device)
779 {
780 	struct proc_dir_entry *entry = NULL;
781 	int i;
782 
783 	if (!acpi_device_dir(device)) {
784 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
785 						     acpi_battery_dir);
786 		if (!acpi_device_dir(device))
787 			return -ENODEV;
788 	}
789 
790 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
791 		entry = proc_create_data(acpi_battery_file[i].name,
792 					 acpi_battery_file[i].mode,
793 					 acpi_device_dir(device),
794 					 &acpi_battery_file[i].ops,
795 					 acpi_driver_data(device));
796 		if (!entry)
797 			return -ENODEV;
798 	}
799 	return 0;
800 }
801 
802 static void acpi_battery_remove_fs(struct acpi_device *device)
803 {
804 	int i;
805 	if (!acpi_device_dir(device))
806 		return;
807 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
808 		remove_proc_entry(acpi_battery_file[i].name,
809 				  acpi_device_dir(device));
810 
811 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
812 	acpi_device_dir(device) = NULL;
813 }
814 
815 #endif
816 
817 /* --------------------------------------------------------------------------
818                                  Driver Interface
819    -------------------------------------------------------------------------- */
820 
821 static void acpi_battery_notify(struct acpi_device *device, u32 event)
822 {
823 	struct acpi_battery *battery = acpi_driver_data(device);
824 
825 	if (!battery)
826 		return;
827 	acpi_battery_update(battery);
828 	acpi_bus_generate_proc_event(device, event,
829 				     acpi_battery_present(battery));
830 	acpi_bus_generate_netlink_event(device->pnp.device_class,
831 					dev_name(&device->dev), event,
832 					acpi_battery_present(battery));
833 #ifdef CONFIG_ACPI_SYSFS_POWER
834 	/* acpi_battery_update could remove power_supply object */
835 	if (battery->bat.dev)
836 		kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
837 #endif
838 }
839 
840 static int acpi_battery_add(struct acpi_device *device)
841 {
842 	int result = 0;
843 	struct acpi_battery *battery = NULL;
844 	if (!device)
845 		return -EINVAL;
846 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
847 	if (!battery)
848 		return -ENOMEM;
849 	battery->device = device;
850 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
851 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
852 	device->driver_data = battery;
853 	mutex_init(&battery->lock);
854 	acpi_battery_update(battery);
855 #ifdef CONFIG_ACPI_PROCFS_POWER
856 	result = acpi_battery_add_fs(device);
857 #endif
858 	if (!result) {
859 		printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
860 			ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
861 			device->status.battery_present ? "present" : "absent");
862 	} else {
863 #ifdef CONFIG_ACPI_PROCFS_POWER
864 		acpi_battery_remove_fs(device);
865 #endif
866 		kfree(battery);
867 	}
868 	return result;
869 }
870 
871 static int acpi_battery_remove(struct acpi_device *device, int type)
872 {
873 	struct acpi_battery *battery = NULL;
874 
875 	if (!device || !acpi_driver_data(device))
876 		return -EINVAL;
877 	battery = acpi_driver_data(device);
878 #ifdef CONFIG_ACPI_PROCFS_POWER
879 	acpi_battery_remove_fs(device);
880 #endif
881 #ifdef CONFIG_ACPI_SYSFS_POWER
882 	sysfs_remove_battery(battery);
883 #endif
884 	mutex_destroy(&battery->lock);
885 	kfree(battery);
886 	return 0;
887 }
888 
889 /* this is needed to learn about changes made in suspended state */
890 static int acpi_battery_resume(struct acpi_device *device)
891 {
892 	struct acpi_battery *battery;
893 	if (!device)
894 		return -EINVAL;
895 	battery = acpi_driver_data(device);
896 	battery->update_time = 0;
897 	acpi_battery_update(battery);
898 	return 0;
899 }
900 
901 static struct acpi_driver acpi_battery_driver = {
902 	.name = "battery",
903 	.class = ACPI_BATTERY_CLASS,
904 	.ids = battery_device_ids,
905 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
906 	.ops = {
907 		.add = acpi_battery_add,
908 		.resume = acpi_battery_resume,
909 		.remove = acpi_battery_remove,
910 		.notify = acpi_battery_notify,
911 		},
912 };
913 
914 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
915 {
916 	if (acpi_disabled)
917 		return;
918 #ifdef CONFIG_ACPI_PROCFS_POWER
919 	acpi_battery_dir = acpi_lock_battery_dir();
920 	if (!acpi_battery_dir)
921 		return;
922 #endif
923 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
924 #ifdef CONFIG_ACPI_PROCFS_POWER
925 		acpi_unlock_battery_dir(acpi_battery_dir);
926 #endif
927 		return;
928 	}
929 	return;
930 }
931 
932 static int __init acpi_battery_init(void)
933 {
934 	async_schedule(acpi_battery_init_async, NULL);
935 	return 0;
936 }
937 
938 static void __exit acpi_battery_exit(void)
939 {
940 	acpi_bus_unregister_driver(&acpi_battery_driver);
941 #ifdef CONFIG_ACPI_PROCFS_POWER
942 	acpi_unlock_battery_dir(acpi_battery_dir);
943 #endif
944 }
945 
946 module_init(acpi_battery_init);
947 module_exit(acpi_battery_exit);
948