xref: /linux/drivers/acpi/battery.c (revision e724e7aaf9ca794670a4d4931af7a7e24e37fec3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  battery.c - ACPI Battery Driver (Revision: 2.0)
4  *
5  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
6  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  */
10 
11 #define pr_fmt(fmt) "ACPI: battery: " fmt
12 
13 #include <linux/async.h>
14 #include <linux/delay.h>
15 #include <linux/dmi.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/suspend.h>
23 #include <linux/types.h>
24 
25 #include <asm/unaligned.h>
26 
27 #include <linux/acpi.h>
28 #include <linux/power_supply.h>
29 
30 #include <acpi/battery.h>
31 
32 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
33 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
34 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
35 
36 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
37 
38 /* Battery power unit: 0 means mW, 1 means mA */
39 #define ACPI_BATTERY_POWER_UNIT_MA	1
40 
41 #define ACPI_BATTERY_STATE_DISCHARGING	0x1
42 #define ACPI_BATTERY_STATE_CHARGING	0x2
43 #define ACPI_BATTERY_STATE_CRITICAL	0x4
44 
45 #define MAX_STRING_LENGTH	64
46 
47 MODULE_AUTHOR("Paul Diefenbaugh");
48 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
49 MODULE_DESCRIPTION("ACPI Battery Driver");
50 MODULE_LICENSE("GPL");
51 
52 static async_cookie_t async_cookie;
53 static bool battery_driver_registered;
54 static int battery_bix_broken_package;
55 static int battery_notification_delay_ms;
56 static int battery_ac_is_broken;
57 static unsigned int cache_time = 1000;
58 module_param(cache_time, uint, 0644);
59 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
60 
61 static const struct acpi_device_id battery_device_ids[] = {
62 	{"PNP0C0A", 0},
63 
64 	/* Microsoft Surface Go 3 */
65 	{"MSHW0146", 0},
66 
67 	{"", 0},
68 };
69 
70 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
71 
72 enum {
73 	ACPI_BATTERY_ALARM_PRESENT,
74 	ACPI_BATTERY_XINFO_PRESENT,
75 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
76 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
77 	 * switches between mWh and mAh depending on whether the system
78 	 * is running on battery or not.  When mAh is the unit, most
79 	 * reported values are incorrect and need to be adjusted by
80 	 * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
81 	 * Pre-2010 and 2012 models appear to always report in mWh and
82 	 * are thus unaffected (tested with t42, t61, t500, x200, x300,
83 	 * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
84 	 *  the 2011 models that fixes the issue (tested on x220 with a
85 	 * post-1.29 BIOS), but as of Nov. 2012, no such update is
86 	 * available for the 2010 models.
87 	 */
88 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
89 	/* for batteries reporting current capacity with design capacity
90 	 * on a full charge, but showing degradation in full charge cap.
91 	 */
92 	ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
93 };
94 
95 struct acpi_battery {
96 	struct mutex lock;
97 	struct mutex sysfs_lock;
98 	struct power_supply *bat;
99 	struct power_supply_desc bat_desc;
100 	struct acpi_device *device;
101 	struct notifier_block pm_nb;
102 	struct list_head list;
103 	unsigned long update_time;
104 	int revision;
105 	int rate_now;
106 	int capacity_now;
107 	int voltage_now;
108 	int design_capacity;
109 	int full_charge_capacity;
110 	int technology;
111 	int design_voltage;
112 	int design_capacity_warning;
113 	int design_capacity_low;
114 	int cycle_count;
115 	int measurement_accuracy;
116 	int max_sampling_time;
117 	int min_sampling_time;
118 	int max_averaging_interval;
119 	int min_averaging_interval;
120 	int capacity_granularity_1;
121 	int capacity_granularity_2;
122 	int alarm;
123 	char model_number[MAX_STRING_LENGTH];
124 	char serial_number[MAX_STRING_LENGTH];
125 	char type[MAX_STRING_LENGTH];
126 	char oem_info[MAX_STRING_LENGTH];
127 	int state;
128 	int power_unit;
129 	unsigned long flags;
130 };
131 
132 #define to_acpi_battery(x) power_supply_get_drvdata(x)
133 
134 static inline int acpi_battery_present(struct acpi_battery *battery)
135 {
136 	return battery->device->status.battery_present;
137 }
138 
139 static int acpi_battery_technology(struct acpi_battery *battery)
140 {
141 	if (!strcasecmp("NiCd", battery->type))
142 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
143 	if (!strcasecmp("NiMH", battery->type))
144 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
145 	if (!strcasecmp("LION", battery->type))
146 		return POWER_SUPPLY_TECHNOLOGY_LION;
147 	if (!strncasecmp("LI-ION", battery->type, 6))
148 		return POWER_SUPPLY_TECHNOLOGY_LION;
149 	if (!strcasecmp("LiP", battery->type))
150 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
151 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
152 }
153 
154 static int acpi_battery_get_state(struct acpi_battery *battery);
155 
156 static int acpi_battery_is_charged(struct acpi_battery *battery)
157 {
158 	/* charging, discharging or critical low */
159 	if (battery->state != 0)
160 		return 0;
161 
162 	/* battery not reporting charge */
163 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
164 	    battery->capacity_now == 0)
165 		return 0;
166 
167 	/* good batteries update full_charge as the batteries degrade */
168 	if (battery->full_charge_capacity == battery->capacity_now)
169 		return 1;
170 
171 	/* fallback to using design values for broken batteries */
172 	if (battery->design_capacity <= battery->capacity_now)
173 		return 1;
174 
175 	/* we don't do any sort of metric based on percentages */
176 	return 0;
177 }
178 
179 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
180 {
181 	return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
182 		ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
183 		battery->full_charge_capacity < battery->design_capacity;
184 }
185 
186 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
187 {
188 	/*
189 	 * Some devices wrongly report discharging if the battery's charge level
190 	 * was above the device's start charging threshold atm the AC adapter
191 	 * was plugged in and the device thus did not start a new charge cycle.
192 	 */
193 	if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
194 	    battery->rate_now == 0)
195 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
196 
197 	return POWER_SUPPLY_STATUS_DISCHARGING;
198 }
199 
200 static int acpi_battery_get_property(struct power_supply *psy,
201 				     enum power_supply_property psp,
202 				     union power_supply_propval *val)
203 {
204 	int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
205 	struct acpi_battery *battery = to_acpi_battery(psy);
206 
207 	if (acpi_battery_present(battery)) {
208 		/* run battery update only if it is present */
209 		acpi_battery_get_state(battery);
210 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
211 		return -ENODEV;
212 	switch (psp) {
213 	case POWER_SUPPLY_PROP_STATUS:
214 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
215 			val->intval = acpi_battery_handle_discharging(battery);
216 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
217 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
218 		else if (acpi_battery_is_charged(battery))
219 			val->intval = POWER_SUPPLY_STATUS_FULL;
220 		else
221 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
222 		break;
223 	case POWER_SUPPLY_PROP_PRESENT:
224 		val->intval = acpi_battery_present(battery);
225 		break;
226 	case POWER_SUPPLY_PROP_TECHNOLOGY:
227 		val->intval = acpi_battery_technology(battery);
228 		break;
229 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
230 		val->intval = battery->cycle_count;
231 		break;
232 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
233 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
234 			ret = -ENODEV;
235 		else
236 			val->intval = battery->design_voltage * 1000;
237 		break;
238 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
239 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
240 			ret = -ENODEV;
241 		else
242 			val->intval = battery->voltage_now * 1000;
243 		break;
244 	case POWER_SUPPLY_PROP_CURRENT_NOW:
245 	case POWER_SUPPLY_PROP_POWER_NOW:
246 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
247 			ret = -ENODEV;
248 		else
249 			val->intval = battery->rate_now * 1000;
250 		break;
251 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
252 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
253 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
254 			ret = -ENODEV;
255 		else
256 			val->intval = battery->design_capacity * 1000;
257 		break;
258 	case POWER_SUPPLY_PROP_CHARGE_FULL:
259 	case POWER_SUPPLY_PROP_ENERGY_FULL:
260 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
261 			ret = -ENODEV;
262 		else
263 			val->intval = battery->full_charge_capacity * 1000;
264 		break;
265 	case POWER_SUPPLY_PROP_CHARGE_NOW:
266 	case POWER_SUPPLY_PROP_ENERGY_NOW:
267 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
268 			ret = -ENODEV;
269 		else
270 			val->intval = battery->capacity_now * 1000;
271 		break;
272 	case POWER_SUPPLY_PROP_CAPACITY:
273 		if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
274 			full_capacity = battery->full_charge_capacity;
275 		else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
276 			full_capacity = battery->design_capacity;
277 
278 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
279 		    full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
280 			ret = -ENODEV;
281 		else
282 			val->intval = battery->capacity_now * 100/
283 					full_capacity;
284 		break;
285 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
286 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
287 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
288 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
289 			(battery->capacity_now <= battery->alarm))
290 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
291 		else if (acpi_battery_is_charged(battery))
292 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
293 		else
294 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
295 		break;
296 	case POWER_SUPPLY_PROP_MODEL_NAME:
297 		val->strval = battery->model_number;
298 		break;
299 	case POWER_SUPPLY_PROP_MANUFACTURER:
300 		val->strval = battery->oem_info;
301 		break;
302 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
303 		val->strval = battery->serial_number;
304 		break;
305 	default:
306 		ret = -EINVAL;
307 	}
308 	return ret;
309 }
310 
311 static enum power_supply_property charge_battery_props[] = {
312 	POWER_SUPPLY_PROP_STATUS,
313 	POWER_SUPPLY_PROP_PRESENT,
314 	POWER_SUPPLY_PROP_TECHNOLOGY,
315 	POWER_SUPPLY_PROP_CYCLE_COUNT,
316 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
317 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
318 	POWER_SUPPLY_PROP_CURRENT_NOW,
319 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
320 	POWER_SUPPLY_PROP_CHARGE_FULL,
321 	POWER_SUPPLY_PROP_CHARGE_NOW,
322 	POWER_SUPPLY_PROP_CAPACITY,
323 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
324 	POWER_SUPPLY_PROP_MODEL_NAME,
325 	POWER_SUPPLY_PROP_MANUFACTURER,
326 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
327 };
328 
329 static enum power_supply_property charge_battery_full_cap_broken_props[] = {
330 	POWER_SUPPLY_PROP_STATUS,
331 	POWER_SUPPLY_PROP_PRESENT,
332 	POWER_SUPPLY_PROP_TECHNOLOGY,
333 	POWER_SUPPLY_PROP_CYCLE_COUNT,
334 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
335 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
336 	POWER_SUPPLY_PROP_CURRENT_NOW,
337 	POWER_SUPPLY_PROP_CHARGE_NOW,
338 	POWER_SUPPLY_PROP_MODEL_NAME,
339 	POWER_SUPPLY_PROP_MANUFACTURER,
340 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
341 };
342 
343 static enum power_supply_property energy_battery_props[] = {
344 	POWER_SUPPLY_PROP_STATUS,
345 	POWER_SUPPLY_PROP_PRESENT,
346 	POWER_SUPPLY_PROP_TECHNOLOGY,
347 	POWER_SUPPLY_PROP_CYCLE_COUNT,
348 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
349 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
350 	POWER_SUPPLY_PROP_POWER_NOW,
351 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
352 	POWER_SUPPLY_PROP_ENERGY_FULL,
353 	POWER_SUPPLY_PROP_ENERGY_NOW,
354 	POWER_SUPPLY_PROP_CAPACITY,
355 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
356 	POWER_SUPPLY_PROP_MODEL_NAME,
357 	POWER_SUPPLY_PROP_MANUFACTURER,
358 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
359 };
360 
361 static enum power_supply_property energy_battery_full_cap_broken_props[] = {
362 	POWER_SUPPLY_PROP_STATUS,
363 	POWER_SUPPLY_PROP_PRESENT,
364 	POWER_SUPPLY_PROP_TECHNOLOGY,
365 	POWER_SUPPLY_PROP_CYCLE_COUNT,
366 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
367 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
368 	POWER_SUPPLY_PROP_POWER_NOW,
369 	POWER_SUPPLY_PROP_ENERGY_NOW,
370 	POWER_SUPPLY_PROP_MODEL_NAME,
371 	POWER_SUPPLY_PROP_MANUFACTURER,
372 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
373 };
374 
375 /* Battery Management */
376 struct acpi_offsets {
377 	size_t offset;		/* offset inside struct acpi_sbs_battery */
378 	u8 mode;		/* int or string? */
379 };
380 
381 static const struct acpi_offsets state_offsets[] = {
382 	{offsetof(struct acpi_battery, state), 0},
383 	{offsetof(struct acpi_battery, rate_now), 0},
384 	{offsetof(struct acpi_battery, capacity_now), 0},
385 	{offsetof(struct acpi_battery, voltage_now), 0},
386 };
387 
388 static const struct acpi_offsets info_offsets[] = {
389 	{offsetof(struct acpi_battery, power_unit), 0},
390 	{offsetof(struct acpi_battery, design_capacity), 0},
391 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
392 	{offsetof(struct acpi_battery, technology), 0},
393 	{offsetof(struct acpi_battery, design_voltage), 0},
394 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
395 	{offsetof(struct acpi_battery, design_capacity_low), 0},
396 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
397 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
398 	{offsetof(struct acpi_battery, model_number), 1},
399 	{offsetof(struct acpi_battery, serial_number), 1},
400 	{offsetof(struct acpi_battery, type), 1},
401 	{offsetof(struct acpi_battery, oem_info), 1},
402 };
403 
404 static const struct acpi_offsets extended_info_offsets[] = {
405 	{offsetof(struct acpi_battery, revision), 0},
406 	{offsetof(struct acpi_battery, power_unit), 0},
407 	{offsetof(struct acpi_battery, design_capacity), 0},
408 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
409 	{offsetof(struct acpi_battery, technology), 0},
410 	{offsetof(struct acpi_battery, design_voltage), 0},
411 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
412 	{offsetof(struct acpi_battery, design_capacity_low), 0},
413 	{offsetof(struct acpi_battery, cycle_count), 0},
414 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
415 	{offsetof(struct acpi_battery, max_sampling_time), 0},
416 	{offsetof(struct acpi_battery, min_sampling_time), 0},
417 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
418 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
419 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
420 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
421 	{offsetof(struct acpi_battery, model_number), 1},
422 	{offsetof(struct acpi_battery, serial_number), 1},
423 	{offsetof(struct acpi_battery, type), 1},
424 	{offsetof(struct acpi_battery, oem_info), 1},
425 };
426 
427 static int extract_package(struct acpi_battery *battery,
428 			   union acpi_object *package,
429 			   const struct acpi_offsets *offsets, int num)
430 {
431 	int i;
432 	union acpi_object *element;
433 
434 	if (package->type != ACPI_TYPE_PACKAGE)
435 		return -EFAULT;
436 	for (i = 0; i < num; ++i) {
437 		if (package->package.count <= i)
438 			return -EFAULT;
439 		element = &package->package.elements[i];
440 		if (offsets[i].mode) {
441 			u8 *ptr = (u8 *)battery + offsets[i].offset;
442 			u32 len = MAX_STRING_LENGTH;
443 
444 			switch (element->type) {
445 			case ACPI_TYPE_BUFFER:
446 				if (len > element->buffer.length + 1)
447 					len = element->buffer.length + 1;
448 
449 				fallthrough;
450 			case ACPI_TYPE_STRING:
451 				strscpy(ptr, element->string.pointer, len);
452 
453 				break;
454 			case ACPI_TYPE_INTEGER:
455 				strscpy(ptr, (u8 *)&element->integer.value, sizeof(u64) + 1);
456 
457 				break;
458 			default:
459 				*ptr = 0; /* don't have value */
460 			}
461 		} else {
462 			int *x = (int *)((u8 *)battery + offsets[i].offset);
463 			*x = (element->type == ACPI_TYPE_INTEGER) ?
464 				element->integer.value : -1;
465 		}
466 	}
467 	return 0;
468 }
469 
470 static int acpi_battery_get_status(struct acpi_battery *battery)
471 {
472 	if (acpi_bus_get_status(battery->device)) {
473 		acpi_handle_info(battery->device->handle,
474 				 "_STA evaluation failed\n");
475 		return -ENODEV;
476 	}
477 	return 0;
478 }
479 
480 
481 static int extract_battery_info(const int use_bix,
482 			 struct acpi_battery *battery,
483 			 const struct acpi_buffer *buffer)
484 {
485 	int result = -EFAULT;
486 
487 	if (use_bix && battery_bix_broken_package)
488 		result = extract_package(battery, buffer->pointer,
489 				extended_info_offsets + 1,
490 				ARRAY_SIZE(extended_info_offsets) - 1);
491 	else if (use_bix)
492 		result = extract_package(battery, buffer->pointer,
493 				extended_info_offsets,
494 				ARRAY_SIZE(extended_info_offsets));
495 	else
496 		result = extract_package(battery, buffer->pointer,
497 				info_offsets, ARRAY_SIZE(info_offsets));
498 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
499 		battery->full_charge_capacity = battery->design_capacity;
500 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
501 	    battery->power_unit && battery->design_voltage) {
502 		battery->design_capacity = battery->design_capacity *
503 		    10000 / battery->design_voltage;
504 		battery->full_charge_capacity = battery->full_charge_capacity *
505 		    10000 / battery->design_voltage;
506 		battery->design_capacity_warning =
507 		    battery->design_capacity_warning *
508 		    10000 / battery->design_voltage;
509 		/* Curiously, design_capacity_low, unlike the rest of them,
510 		 *  is correct.
511 		 */
512 		/* capacity_granularity_* equal 1 on the systems tested, so
513 		 * it's impossible to tell if they would need an adjustment
514 		 * or not if their values were higher.
515 		 */
516 	}
517 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
518 	    battery->capacity_now > battery->full_charge_capacity)
519 		battery->capacity_now = battery->full_charge_capacity;
520 
521 	return result;
522 }
523 
524 static int acpi_battery_get_info(struct acpi_battery *battery)
525 {
526 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
527 	int use_bix;
528 	int result = -ENODEV;
529 
530 	if (!acpi_battery_present(battery))
531 		return 0;
532 
533 
534 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
535 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
536 		acpi_status status = AE_ERROR;
537 
538 		mutex_lock(&battery->lock);
539 		status = acpi_evaluate_object(battery->device->handle,
540 					      use_bix ? "_BIX":"_BIF",
541 					      NULL, &buffer);
542 		mutex_unlock(&battery->lock);
543 
544 		if (ACPI_FAILURE(status)) {
545 			acpi_handle_info(battery->device->handle,
546 					 "%s evaluation failed: %s\n",
547 					 use_bix ? "_BIX":"_BIF",
548 					 acpi_format_exception(status));
549 		} else {
550 			result = extract_battery_info(use_bix,
551 						      battery,
552 						      &buffer);
553 
554 			kfree(buffer.pointer);
555 			break;
556 		}
557 	}
558 
559 	if (!result && !use_bix && xinfo)
560 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
561 
562 	return result;
563 }
564 
565 static int acpi_battery_get_state(struct acpi_battery *battery)
566 {
567 	int result = 0;
568 	acpi_status status = 0;
569 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
570 
571 	if (!acpi_battery_present(battery))
572 		return 0;
573 
574 	if (battery->update_time &&
575 	    time_before(jiffies, battery->update_time +
576 			msecs_to_jiffies(cache_time)))
577 		return 0;
578 
579 	mutex_lock(&battery->lock);
580 	status = acpi_evaluate_object(battery->device->handle, "_BST",
581 				      NULL, &buffer);
582 	mutex_unlock(&battery->lock);
583 
584 	if (ACPI_FAILURE(status)) {
585 		acpi_handle_info(battery->device->handle,
586 				 "_BST evaluation failed: %s",
587 				 acpi_format_exception(status));
588 		return -ENODEV;
589 	}
590 
591 	result = extract_package(battery, buffer.pointer,
592 				 state_offsets, ARRAY_SIZE(state_offsets));
593 	battery->update_time = jiffies;
594 	kfree(buffer.pointer);
595 
596 	/* For buggy DSDTs that report negative 16-bit values for either
597 	 * charging or discharging current and/or report 0 as 65536
598 	 * due to bad math.
599 	 */
600 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
601 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
602 		(s16)(battery->rate_now) < 0) {
603 		battery->rate_now = abs((s16)battery->rate_now);
604 		pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
605 	}
606 
607 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
608 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
609 		battery->capacity_now = (battery->capacity_now *
610 				battery->full_charge_capacity) / 100;
611 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
612 	    battery->power_unit && battery->design_voltage) {
613 		battery->capacity_now = battery->capacity_now *
614 		    10000 / battery->design_voltage;
615 	}
616 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
617 	    battery->capacity_now > battery->full_charge_capacity)
618 		battery->capacity_now = battery->full_charge_capacity;
619 
620 	return result;
621 }
622 
623 static int acpi_battery_set_alarm(struct acpi_battery *battery)
624 {
625 	acpi_status status = 0;
626 
627 	if (!acpi_battery_present(battery) ||
628 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
629 		return -ENODEV;
630 
631 	mutex_lock(&battery->lock);
632 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
633 					    battery->alarm);
634 	mutex_unlock(&battery->lock);
635 
636 	if (ACPI_FAILURE(status))
637 		return -ENODEV;
638 
639 	acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
640 			  battery->alarm);
641 
642 	return 0;
643 }
644 
645 static int acpi_battery_init_alarm(struct acpi_battery *battery)
646 {
647 	/* See if alarms are supported, and if so, set default */
648 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
649 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
650 		return 0;
651 	}
652 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
653 	if (!battery->alarm)
654 		battery->alarm = battery->design_capacity_warning;
655 	return acpi_battery_set_alarm(battery);
656 }
657 
658 static ssize_t acpi_battery_alarm_show(struct device *dev,
659 					struct device_attribute *attr,
660 					char *buf)
661 {
662 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
663 
664 	return sprintf(buf, "%d\n", battery->alarm * 1000);
665 }
666 
667 static ssize_t acpi_battery_alarm_store(struct device *dev,
668 					struct device_attribute *attr,
669 					const char *buf, size_t count)
670 {
671 	unsigned long x;
672 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
673 
674 	if (sscanf(buf, "%lu\n", &x) == 1)
675 		battery->alarm = x/1000;
676 	if (acpi_battery_present(battery))
677 		acpi_battery_set_alarm(battery);
678 	return count;
679 }
680 
681 static const struct device_attribute alarm_attr = {
682 	.attr = {.name = "alarm", .mode = 0644},
683 	.show = acpi_battery_alarm_show,
684 	.store = acpi_battery_alarm_store,
685 };
686 
687 /*
688  * The Battery Hooking API
689  *
690  * This API is used inside other drivers that need to expose
691  * platform-specific behaviour within the generic driver in a
692  * generic way.
693  *
694  */
695 
696 static LIST_HEAD(acpi_battery_list);
697 static LIST_HEAD(battery_hook_list);
698 static DEFINE_MUTEX(hook_mutex);
699 
700 static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
701 {
702 	struct acpi_battery *battery;
703 	/*
704 	 * In order to remove a hook, we first need to
705 	 * de-register all the batteries that are registered.
706 	 */
707 	if (lock)
708 		mutex_lock(&hook_mutex);
709 	list_for_each_entry(battery, &acpi_battery_list, list) {
710 		if (!hook->remove_battery(battery->bat, hook))
711 			power_supply_changed(battery->bat);
712 	}
713 	list_del(&hook->list);
714 	if (lock)
715 		mutex_unlock(&hook_mutex);
716 	pr_info("extension unregistered: %s\n", hook->name);
717 }
718 
719 void battery_hook_unregister(struct acpi_battery_hook *hook)
720 {
721 	__battery_hook_unregister(hook, 1);
722 }
723 EXPORT_SYMBOL_GPL(battery_hook_unregister);
724 
725 void battery_hook_register(struct acpi_battery_hook *hook)
726 {
727 	struct acpi_battery *battery;
728 
729 	mutex_lock(&hook_mutex);
730 	INIT_LIST_HEAD(&hook->list);
731 	list_add(&hook->list, &battery_hook_list);
732 	/*
733 	 * Now that the driver is registered, we need
734 	 * to notify the hook that a battery is available
735 	 * for each battery, so that the driver may add
736 	 * its attributes.
737 	 */
738 	list_for_each_entry(battery, &acpi_battery_list, list) {
739 		if (hook->add_battery(battery->bat, hook)) {
740 			/*
741 			 * If a add-battery returns non-zero,
742 			 * the registration of the extension has failed,
743 			 * and we will not add it to the list of loaded
744 			 * hooks.
745 			 */
746 			pr_err("extension failed to load: %s", hook->name);
747 			__battery_hook_unregister(hook, 0);
748 			goto end;
749 		}
750 
751 		power_supply_changed(battery->bat);
752 	}
753 	pr_info("new extension: %s\n", hook->name);
754 end:
755 	mutex_unlock(&hook_mutex);
756 }
757 EXPORT_SYMBOL_GPL(battery_hook_register);
758 
759 /*
760  * This function gets called right after the battery sysfs
761  * attributes have been added, so that the drivers that
762  * define custom sysfs attributes can add their own.
763  */
764 static void battery_hook_add_battery(struct acpi_battery *battery)
765 {
766 	struct acpi_battery_hook *hook_node, *tmp;
767 
768 	mutex_lock(&hook_mutex);
769 	INIT_LIST_HEAD(&battery->list);
770 	list_add(&battery->list, &acpi_battery_list);
771 	/*
772 	 * Since we added a new battery to the list, we need to
773 	 * iterate over the hooks and call add_battery for each
774 	 * hook that was registered. This usually happens
775 	 * when a battery gets hotplugged or initialized
776 	 * during the battery module initialization.
777 	 */
778 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
779 		if (hook_node->add_battery(battery->bat, hook_node)) {
780 			/*
781 			 * The notification of the extensions has failed, to
782 			 * prevent further errors we will unload the extension.
783 			 */
784 			pr_err("error in extension, unloading: %s",
785 					hook_node->name);
786 			__battery_hook_unregister(hook_node, 0);
787 		}
788 	}
789 	mutex_unlock(&hook_mutex);
790 }
791 
792 static void battery_hook_remove_battery(struct acpi_battery *battery)
793 {
794 	struct acpi_battery_hook *hook;
795 
796 	mutex_lock(&hook_mutex);
797 	/*
798 	 * Before removing the hook, we need to remove all
799 	 * custom attributes from the battery.
800 	 */
801 	list_for_each_entry(hook, &battery_hook_list, list) {
802 		hook->remove_battery(battery->bat, hook);
803 	}
804 	/* Then, just remove the battery from the list */
805 	list_del(&battery->list);
806 	mutex_unlock(&hook_mutex);
807 }
808 
809 static void __exit battery_hook_exit(void)
810 {
811 	struct acpi_battery_hook *hook;
812 	struct acpi_battery_hook *ptr;
813 	/*
814 	 * At this point, the acpi_bus_unregister_driver()
815 	 * has called remove for all batteries. We just
816 	 * need to remove the hooks.
817 	 */
818 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
819 		__battery_hook_unregister(hook, 1);
820 	}
821 	mutex_destroy(&hook_mutex);
822 }
823 
824 static int sysfs_add_battery(struct acpi_battery *battery)
825 {
826 	struct power_supply_config psy_cfg = { .drv_data = battery, };
827 	bool full_cap_broken = false;
828 
829 	if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
830 	    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
831 		full_cap_broken = true;
832 
833 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
834 		if (full_cap_broken) {
835 			battery->bat_desc.properties =
836 			    charge_battery_full_cap_broken_props;
837 			battery->bat_desc.num_properties =
838 			    ARRAY_SIZE(charge_battery_full_cap_broken_props);
839 		} else {
840 			battery->bat_desc.properties = charge_battery_props;
841 			battery->bat_desc.num_properties =
842 			    ARRAY_SIZE(charge_battery_props);
843 		}
844 	} else {
845 		if (full_cap_broken) {
846 			battery->bat_desc.properties =
847 			    energy_battery_full_cap_broken_props;
848 			battery->bat_desc.num_properties =
849 			    ARRAY_SIZE(energy_battery_full_cap_broken_props);
850 		} else {
851 			battery->bat_desc.properties = energy_battery_props;
852 			battery->bat_desc.num_properties =
853 			    ARRAY_SIZE(energy_battery_props);
854 		}
855 	}
856 
857 	battery->bat_desc.name = acpi_device_bid(battery->device);
858 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
859 	battery->bat_desc.get_property = acpi_battery_get_property;
860 
861 	battery->bat = power_supply_register_no_ws(&battery->device->dev,
862 				&battery->bat_desc, &psy_cfg);
863 
864 	if (IS_ERR(battery->bat)) {
865 		int result = PTR_ERR(battery->bat);
866 
867 		battery->bat = NULL;
868 		return result;
869 	}
870 	battery_hook_add_battery(battery);
871 	return device_create_file(&battery->bat->dev, &alarm_attr);
872 }
873 
874 static void sysfs_remove_battery(struct acpi_battery *battery)
875 {
876 	mutex_lock(&battery->sysfs_lock);
877 	if (!battery->bat) {
878 		mutex_unlock(&battery->sysfs_lock);
879 		return;
880 	}
881 	battery_hook_remove_battery(battery);
882 	device_remove_file(&battery->bat->dev, &alarm_attr);
883 	power_supply_unregister(battery->bat);
884 	battery->bat = NULL;
885 	mutex_unlock(&battery->sysfs_lock);
886 }
887 
888 static void find_battery(const struct dmi_header *dm, void *private)
889 {
890 	struct acpi_battery *battery = (struct acpi_battery *)private;
891 	/* Note: the hardcoded offsets below have been extracted from
892 	 * the source code of dmidecode.
893 	 */
894 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
895 		const u8 *dmi_data = (const u8 *)(dm + 1);
896 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
897 
898 		if (dm->length >= 18)
899 			dmi_capacity *= dmi_data[17];
900 		if (battery->design_capacity * battery->design_voltage / 1000
901 		    != dmi_capacity &&
902 		    battery->design_capacity * 10 == dmi_capacity)
903 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
904 				&battery->flags);
905 	}
906 }
907 
908 /*
909  * According to the ACPI spec, some kinds of primary batteries can
910  * report percentage battery remaining capacity directly to OS.
911  * In this case, it reports the Last Full Charged Capacity == 100
912  * and BatteryPresentRate == 0xFFFFFFFF.
913  *
914  * Now we found some battery reports percentage remaining capacity
915  * even if it's rechargeable.
916  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
917  *
918  * Handle this correctly so that they won't break userspace.
919  */
920 static void acpi_battery_quirks(struct acpi_battery *battery)
921 {
922 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
923 		return;
924 
925 	if (battery->full_charge_capacity == 100 &&
926 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
927 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
928 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
929 		battery->full_charge_capacity = battery->design_capacity;
930 		battery->capacity_now = (battery->capacity_now *
931 				battery->full_charge_capacity) / 100;
932 	}
933 
934 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
935 		return;
936 
937 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
938 		const char *s;
939 
940 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
941 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
942 			dmi_walk(find_battery, battery);
943 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
944 				     &battery->flags) &&
945 			    battery->design_voltage) {
946 				battery->design_capacity =
947 				    battery->design_capacity *
948 				    10000 / battery->design_voltage;
949 				battery->full_charge_capacity =
950 				    battery->full_charge_capacity *
951 				    10000 / battery->design_voltage;
952 				battery->design_capacity_warning =
953 				    battery->design_capacity_warning *
954 				    10000 / battery->design_voltage;
955 				battery->capacity_now = battery->capacity_now *
956 				    10000 / battery->design_voltage;
957 			}
958 		}
959 	}
960 
961 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
962 		return;
963 
964 	if (acpi_battery_is_degraded(battery) &&
965 	    battery->capacity_now > battery->full_charge_capacity) {
966 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
967 		battery->capacity_now = battery->full_charge_capacity;
968 	}
969 }
970 
971 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
972 {
973 	int result = acpi_battery_get_status(battery);
974 
975 	if (result)
976 		return result;
977 
978 	if (!acpi_battery_present(battery)) {
979 		sysfs_remove_battery(battery);
980 		battery->update_time = 0;
981 		return 0;
982 	}
983 
984 	if (resume)
985 		return 0;
986 
987 	if (!battery->update_time) {
988 		result = acpi_battery_get_info(battery);
989 		if (result)
990 			return result;
991 		acpi_battery_init_alarm(battery);
992 	}
993 
994 	result = acpi_battery_get_state(battery);
995 	if (result)
996 		return result;
997 	acpi_battery_quirks(battery);
998 
999 	if (!battery->bat) {
1000 		result = sysfs_add_battery(battery);
1001 		if (result)
1002 			return result;
1003 	}
1004 
1005 	/*
1006 	 * Wakeup the system if battery is critical low
1007 	 * or lower than the alarm level
1008 	 */
1009 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1010 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1011 	     (battery->capacity_now <= battery->alarm)))
1012 		acpi_pm_wakeup_event(&battery->device->dev);
1013 
1014 	return result;
1015 }
1016 
1017 static void acpi_battery_refresh(struct acpi_battery *battery)
1018 {
1019 	int power_unit;
1020 
1021 	if (!battery->bat)
1022 		return;
1023 
1024 	power_unit = battery->power_unit;
1025 
1026 	acpi_battery_get_info(battery);
1027 
1028 	if (power_unit == battery->power_unit)
1029 		return;
1030 
1031 	/* The battery has changed its reporting units. */
1032 	sysfs_remove_battery(battery);
1033 	sysfs_add_battery(battery);
1034 }
1035 
1036 /* Driver Interface */
1037 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1038 {
1039 	struct acpi_battery *battery = acpi_driver_data(device);
1040 	struct power_supply *old;
1041 
1042 	if (!battery)
1043 		return;
1044 	old = battery->bat;
1045 	/*
1046 	 * On Acer Aspire V5-573G notifications are sometimes triggered too
1047 	 * early. For example, when AC is unplugged and notification is
1048 	 * triggered, battery state is still reported as "Full", and changes to
1049 	 * "Discharging" only after short delay, without any notification.
1050 	 */
1051 	if (battery_notification_delay_ms > 0)
1052 		msleep(battery_notification_delay_ms);
1053 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1054 		acpi_battery_refresh(battery);
1055 	acpi_battery_update(battery, false);
1056 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1057 					dev_name(&device->dev), event,
1058 					acpi_battery_present(battery));
1059 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1060 	/* acpi_battery_update could remove power_supply object */
1061 	if (old && battery->bat)
1062 		power_supply_changed(battery->bat);
1063 }
1064 
1065 static int battery_notify(struct notifier_block *nb,
1066 			       unsigned long mode, void *_unused)
1067 {
1068 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1069 						    pm_nb);
1070 	int result;
1071 
1072 	switch (mode) {
1073 	case PM_POST_HIBERNATION:
1074 	case PM_POST_SUSPEND:
1075 		if (!acpi_battery_present(battery))
1076 			return 0;
1077 
1078 		if (battery->bat) {
1079 			acpi_battery_refresh(battery);
1080 		} else {
1081 			result = acpi_battery_get_info(battery);
1082 			if (result)
1083 				return result;
1084 
1085 			result = sysfs_add_battery(battery);
1086 			if (result)
1087 				return result;
1088 		}
1089 
1090 		acpi_battery_init_alarm(battery);
1091 		acpi_battery_get_state(battery);
1092 		break;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
1098 static int __init
1099 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1100 {
1101 	battery_bix_broken_package = 1;
1102 	return 0;
1103 }
1104 
1105 static int __init
1106 battery_notification_delay_quirk(const struct dmi_system_id *d)
1107 {
1108 	battery_notification_delay_ms = 1000;
1109 	return 0;
1110 }
1111 
1112 static int __init
1113 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1114 {
1115 	battery_ac_is_broken = 1;
1116 	return 0;
1117 }
1118 
1119 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1120 	{
1121 		/* NEC LZ750/LS */
1122 		.callback = battery_bix_broken_package_quirk,
1123 		.matches = {
1124 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1125 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1126 		},
1127 	},
1128 	{
1129 		/* Acer Aspire V5-573G */
1130 		.callback = battery_notification_delay_quirk,
1131 		.matches = {
1132 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1133 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1134 		},
1135 	},
1136 	{
1137 		/* Point of View mobii wintab p800w */
1138 		.callback = battery_ac_is_broken_quirk,
1139 		.matches = {
1140 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1141 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1142 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1143 			/* Above matches are too generic, add bios-date match */
1144 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1145 		},
1146 	},
1147 	{
1148 		/* Microsoft Surface Go 3 */
1149 		.callback = battery_notification_delay_quirk,
1150 		.matches = {
1151 			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1152 			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1153 		},
1154 	},
1155 	{},
1156 };
1157 
1158 /*
1159  * Some machines'(E,G Lenovo Z480) ECs are not stable
1160  * during boot up and this causes battery driver fails to be
1161  * probed due to failure of getting battery information
1162  * from EC sometimes. After several retries, the operation
1163  * may work. So add retry code here and 20ms sleep between
1164  * every retries.
1165  */
1166 static int acpi_battery_update_retry(struct acpi_battery *battery)
1167 {
1168 	int retry, ret;
1169 
1170 	for (retry = 5; retry; retry--) {
1171 		ret = acpi_battery_update(battery, false);
1172 		if (!ret)
1173 			break;
1174 
1175 		msleep(20);
1176 	}
1177 	return ret;
1178 }
1179 
1180 static int acpi_battery_add(struct acpi_device *device)
1181 {
1182 	int result = 0;
1183 	struct acpi_battery *battery = NULL;
1184 
1185 	if (!device)
1186 		return -EINVAL;
1187 
1188 	if (device->dep_unmet)
1189 		return -EPROBE_DEFER;
1190 
1191 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1192 	if (!battery)
1193 		return -ENOMEM;
1194 	battery->device = device;
1195 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1196 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1197 	device->driver_data = battery;
1198 	mutex_init(&battery->lock);
1199 	mutex_init(&battery->sysfs_lock);
1200 	if (acpi_has_method(battery->device->handle, "_BIX"))
1201 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1202 
1203 	result = acpi_battery_update_retry(battery);
1204 	if (result)
1205 		goto fail;
1206 
1207 	pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1208 		device->status.battery_present ? "present" : "absent");
1209 
1210 	battery->pm_nb.notifier_call = battery_notify;
1211 	register_pm_notifier(&battery->pm_nb);
1212 
1213 	device_init_wakeup(&device->dev, 1);
1214 
1215 	return result;
1216 
1217 fail:
1218 	sysfs_remove_battery(battery);
1219 	mutex_destroy(&battery->lock);
1220 	mutex_destroy(&battery->sysfs_lock);
1221 	kfree(battery);
1222 	return result;
1223 }
1224 
1225 static void acpi_battery_remove(struct acpi_device *device)
1226 {
1227 	struct acpi_battery *battery = NULL;
1228 
1229 	if (!device || !acpi_driver_data(device))
1230 		return;
1231 	device_init_wakeup(&device->dev, 0);
1232 	battery = acpi_driver_data(device);
1233 	unregister_pm_notifier(&battery->pm_nb);
1234 	sysfs_remove_battery(battery);
1235 	mutex_destroy(&battery->lock);
1236 	mutex_destroy(&battery->sysfs_lock);
1237 	kfree(battery);
1238 }
1239 
1240 #ifdef CONFIG_PM_SLEEP
1241 /* this is needed to learn about changes made in suspended state */
1242 static int acpi_battery_resume(struct device *dev)
1243 {
1244 	struct acpi_battery *battery;
1245 
1246 	if (!dev)
1247 		return -EINVAL;
1248 
1249 	battery = acpi_driver_data(to_acpi_device(dev));
1250 	if (!battery)
1251 		return -EINVAL;
1252 
1253 	battery->update_time = 0;
1254 	acpi_battery_update(battery, true);
1255 	return 0;
1256 }
1257 #else
1258 #define acpi_battery_resume NULL
1259 #endif
1260 
1261 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1262 
1263 static struct acpi_driver acpi_battery_driver = {
1264 	.name = "battery",
1265 	.class = ACPI_BATTERY_CLASS,
1266 	.ids = battery_device_ids,
1267 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1268 	.ops = {
1269 		.add = acpi_battery_add,
1270 		.remove = acpi_battery_remove,
1271 		.notify = acpi_battery_notify,
1272 		},
1273 	.drv.pm = &acpi_battery_pm,
1274 };
1275 
1276 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1277 {
1278 	int result;
1279 
1280 	if (acpi_quirk_skip_acpi_ac_and_battery())
1281 		return;
1282 
1283 	dmi_check_system(bat_dmi_table);
1284 
1285 	result = acpi_bus_register_driver(&acpi_battery_driver);
1286 	battery_driver_registered = (result == 0);
1287 }
1288 
1289 static int __init acpi_battery_init(void)
1290 {
1291 	if (acpi_disabled)
1292 		return -ENODEV;
1293 
1294 	async_cookie = async_schedule(acpi_battery_init_async, NULL);
1295 	return 0;
1296 }
1297 
1298 static void __exit acpi_battery_exit(void)
1299 {
1300 	async_synchronize_cookie(async_cookie + 1);
1301 	if (battery_driver_registered) {
1302 		acpi_bus_unregister_driver(&acpi_battery_driver);
1303 		battery_hook_exit();
1304 	}
1305 }
1306 
1307 module_init(acpi_battery_init);
1308 module_exit(acpi_battery_exit);
1309