xref: /openbmc/linux/drivers/acpi/battery.c (revision 1c95443e)
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 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 static struct attribute *acpi_battery_attrs[] = {
688 	&alarm_attr.attr,
689 	NULL
690 };
691 ATTRIBUTE_GROUPS(acpi_battery);
692 
693 /*
694  * The Battery Hooking API
695  *
696  * This API is used inside other drivers that need to expose
697  * platform-specific behaviour within the generic driver in a
698  * generic way.
699  *
700  */
701 
702 static LIST_HEAD(acpi_battery_list);
703 static LIST_HEAD(battery_hook_list);
704 static DEFINE_MUTEX(hook_mutex);
705 
706 static void battery_hook_unregister_unlocked(struct acpi_battery_hook *hook)
707 {
708 	struct acpi_battery *battery;
709 
710 	/*
711 	 * In order to remove a hook, we first need to
712 	 * de-register all the batteries that are registered.
713 	 */
714 	list_for_each_entry(battery, &acpi_battery_list, list) {
715 		if (!hook->remove_battery(battery->bat, hook))
716 			power_supply_changed(battery->bat);
717 	}
718 	list_del_init(&hook->list);
719 
720 	pr_info("extension unregistered: %s\n", hook->name);
721 }
722 
723 void battery_hook_unregister(struct acpi_battery_hook *hook)
724 {
725 	mutex_lock(&hook_mutex);
726 	/*
727 	 * Ignore already unregistered battery hooks. This might happen
728 	 * if a battery hook was previously unloaded due to an error when
729 	 * adding a new battery.
730 	 */
731 	if (!list_empty(&hook->list))
732 		battery_hook_unregister_unlocked(hook);
733 
734 	mutex_unlock(&hook_mutex);
735 }
736 EXPORT_SYMBOL_GPL(battery_hook_unregister);
737 
738 void battery_hook_register(struct acpi_battery_hook *hook)
739 {
740 	struct acpi_battery *battery;
741 
742 	mutex_lock(&hook_mutex);
743 	list_add(&hook->list, &battery_hook_list);
744 	/*
745 	 * Now that the driver is registered, we need
746 	 * to notify the hook that a battery is available
747 	 * for each battery, so that the driver may add
748 	 * its attributes.
749 	 */
750 	list_for_each_entry(battery, &acpi_battery_list, list) {
751 		if (hook->add_battery(battery->bat, hook)) {
752 			/*
753 			 * If a add-battery returns non-zero,
754 			 * the registration of the extension has failed,
755 			 * and we will not add it to the list of loaded
756 			 * hooks.
757 			 */
758 			pr_err("extension failed to load: %s", hook->name);
759 			battery_hook_unregister_unlocked(hook);
760 			goto end;
761 		}
762 
763 		power_supply_changed(battery->bat);
764 	}
765 	pr_info("new extension: %s\n", hook->name);
766 end:
767 	mutex_unlock(&hook_mutex);
768 }
769 EXPORT_SYMBOL_GPL(battery_hook_register);
770 
771 /*
772  * This function gets called right after the battery sysfs
773  * attributes have been added, so that the drivers that
774  * define custom sysfs attributes can add their own.
775  */
776 static void battery_hook_add_battery(struct acpi_battery *battery)
777 {
778 	struct acpi_battery_hook *hook_node, *tmp;
779 
780 	mutex_lock(&hook_mutex);
781 	INIT_LIST_HEAD(&battery->list);
782 	list_add(&battery->list, &acpi_battery_list);
783 	/*
784 	 * Since we added a new battery to the list, we need to
785 	 * iterate over the hooks and call add_battery for each
786 	 * hook that was registered. This usually happens
787 	 * when a battery gets hotplugged or initialized
788 	 * during the battery module initialization.
789 	 */
790 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
791 		if (hook_node->add_battery(battery->bat, hook_node)) {
792 			/*
793 			 * The notification of the extensions has failed, to
794 			 * prevent further errors we will unload the extension.
795 			 */
796 			pr_err("error in extension, unloading: %s",
797 					hook_node->name);
798 			battery_hook_unregister_unlocked(hook_node);
799 		}
800 	}
801 	mutex_unlock(&hook_mutex);
802 }
803 
804 static void battery_hook_remove_battery(struct acpi_battery *battery)
805 {
806 	struct acpi_battery_hook *hook;
807 
808 	mutex_lock(&hook_mutex);
809 	/*
810 	 * Before removing the hook, we need to remove all
811 	 * custom attributes from the battery.
812 	 */
813 	list_for_each_entry(hook, &battery_hook_list, list) {
814 		hook->remove_battery(battery->bat, hook);
815 	}
816 	/* Then, just remove the battery from the list */
817 	list_del(&battery->list);
818 	mutex_unlock(&hook_mutex);
819 }
820 
821 static void __exit battery_hook_exit(void)
822 {
823 	struct acpi_battery_hook *hook;
824 	struct acpi_battery_hook *ptr;
825 	/*
826 	 * At this point, the acpi_bus_unregister_driver()
827 	 * has called remove for all batteries. We just
828 	 * need to remove the hooks.
829 	 */
830 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
831 		battery_hook_unregister(hook);
832 	}
833 	mutex_destroy(&hook_mutex);
834 }
835 
836 static int sysfs_add_battery(struct acpi_battery *battery)
837 {
838 	struct power_supply_config psy_cfg = {
839 		.drv_data = battery,
840 		.attr_grp = acpi_battery_groups,
841 	};
842 	bool full_cap_broken = false;
843 
844 	if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
845 	    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
846 		full_cap_broken = true;
847 
848 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
849 		if (full_cap_broken) {
850 			battery->bat_desc.properties =
851 			    charge_battery_full_cap_broken_props;
852 			battery->bat_desc.num_properties =
853 			    ARRAY_SIZE(charge_battery_full_cap_broken_props);
854 		} else {
855 			battery->bat_desc.properties = charge_battery_props;
856 			battery->bat_desc.num_properties =
857 			    ARRAY_SIZE(charge_battery_props);
858 		}
859 	} else {
860 		if (full_cap_broken) {
861 			battery->bat_desc.properties =
862 			    energy_battery_full_cap_broken_props;
863 			battery->bat_desc.num_properties =
864 			    ARRAY_SIZE(energy_battery_full_cap_broken_props);
865 		} else {
866 			battery->bat_desc.properties = energy_battery_props;
867 			battery->bat_desc.num_properties =
868 			    ARRAY_SIZE(energy_battery_props);
869 		}
870 	}
871 
872 	battery->bat_desc.name = acpi_device_bid(battery->device);
873 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
874 	battery->bat_desc.get_property = acpi_battery_get_property;
875 
876 	battery->bat = power_supply_register_no_ws(&battery->device->dev,
877 				&battery->bat_desc, &psy_cfg);
878 
879 	if (IS_ERR(battery->bat)) {
880 		int result = PTR_ERR(battery->bat);
881 
882 		battery->bat = NULL;
883 		return result;
884 	}
885 	battery_hook_add_battery(battery);
886 	return 0;
887 }
888 
889 static void sysfs_remove_battery(struct acpi_battery *battery)
890 {
891 	mutex_lock(&battery->sysfs_lock);
892 	if (!battery->bat) {
893 		mutex_unlock(&battery->sysfs_lock);
894 		return;
895 	}
896 	battery_hook_remove_battery(battery);
897 	power_supply_unregister(battery->bat);
898 	battery->bat = NULL;
899 	mutex_unlock(&battery->sysfs_lock);
900 }
901 
902 static void find_battery(const struct dmi_header *dm, void *private)
903 {
904 	struct acpi_battery *battery = (struct acpi_battery *)private;
905 	/* Note: the hardcoded offsets below have been extracted from
906 	 * the source code of dmidecode.
907 	 */
908 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
909 		const u8 *dmi_data = (const u8 *)(dm + 1);
910 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
911 
912 		if (dm->length >= 18)
913 			dmi_capacity *= dmi_data[17];
914 		if (battery->design_capacity * battery->design_voltage / 1000
915 		    != dmi_capacity &&
916 		    battery->design_capacity * 10 == dmi_capacity)
917 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
918 				&battery->flags);
919 	}
920 }
921 
922 /*
923  * According to the ACPI spec, some kinds of primary batteries can
924  * report percentage battery remaining capacity directly to OS.
925  * In this case, it reports the Last Full Charged Capacity == 100
926  * and BatteryPresentRate == 0xFFFFFFFF.
927  *
928  * Now we found some battery reports percentage remaining capacity
929  * even if it's rechargeable.
930  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
931  *
932  * Handle this correctly so that they won't break userspace.
933  */
934 static void acpi_battery_quirks(struct acpi_battery *battery)
935 {
936 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
937 		return;
938 
939 	if (battery->full_charge_capacity == 100 &&
940 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
941 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
942 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
943 		battery->full_charge_capacity = battery->design_capacity;
944 		battery->capacity_now = (battery->capacity_now *
945 				battery->full_charge_capacity) / 100;
946 	}
947 
948 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
949 		return;
950 
951 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
952 		const char *s;
953 
954 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
955 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
956 			dmi_walk(find_battery, battery);
957 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
958 				     &battery->flags) &&
959 			    battery->design_voltage) {
960 				battery->design_capacity =
961 				    battery->design_capacity *
962 				    10000 / battery->design_voltage;
963 				battery->full_charge_capacity =
964 				    battery->full_charge_capacity *
965 				    10000 / battery->design_voltage;
966 				battery->design_capacity_warning =
967 				    battery->design_capacity_warning *
968 				    10000 / battery->design_voltage;
969 				battery->capacity_now = battery->capacity_now *
970 				    10000 / battery->design_voltage;
971 			}
972 		}
973 	}
974 
975 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
976 		return;
977 
978 	if (acpi_battery_is_degraded(battery) &&
979 	    battery->capacity_now > battery->full_charge_capacity) {
980 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
981 		battery->capacity_now = battery->full_charge_capacity;
982 	}
983 }
984 
985 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
986 {
987 	int result = acpi_battery_get_status(battery);
988 
989 	if (result)
990 		return result;
991 
992 	if (!acpi_battery_present(battery)) {
993 		sysfs_remove_battery(battery);
994 		battery->update_time = 0;
995 		return 0;
996 	}
997 
998 	if (resume)
999 		return 0;
1000 
1001 	if (!battery->update_time) {
1002 		result = acpi_battery_get_info(battery);
1003 		if (result)
1004 			return result;
1005 		acpi_battery_init_alarm(battery);
1006 	}
1007 
1008 	result = acpi_battery_get_state(battery);
1009 	if (result)
1010 		return result;
1011 	acpi_battery_quirks(battery);
1012 
1013 	if (!battery->bat) {
1014 		result = sysfs_add_battery(battery);
1015 		if (result)
1016 			return result;
1017 	}
1018 
1019 	/*
1020 	 * Wakeup the system if battery is critical low
1021 	 * or lower than the alarm level
1022 	 */
1023 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1024 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1025 	     (battery->capacity_now <= battery->alarm)))
1026 		acpi_pm_wakeup_event(&battery->device->dev);
1027 
1028 	return result;
1029 }
1030 
1031 static void acpi_battery_refresh(struct acpi_battery *battery)
1032 {
1033 	int power_unit;
1034 
1035 	if (!battery->bat)
1036 		return;
1037 
1038 	power_unit = battery->power_unit;
1039 
1040 	acpi_battery_get_info(battery);
1041 
1042 	if (power_unit == battery->power_unit)
1043 		return;
1044 
1045 	/* The battery has changed its reporting units. */
1046 	sysfs_remove_battery(battery);
1047 	sysfs_add_battery(battery);
1048 }
1049 
1050 /* Driver Interface */
1051 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
1052 {
1053 	struct acpi_device *device = data;
1054 	struct acpi_battery *battery = acpi_driver_data(device);
1055 	struct power_supply *old;
1056 
1057 	if (!battery)
1058 		return;
1059 	old = battery->bat;
1060 	/*
1061 	 * On Acer Aspire V5-573G notifications are sometimes triggered too
1062 	 * early. For example, when AC is unplugged and notification is
1063 	 * triggered, battery state is still reported as "Full", and changes to
1064 	 * "Discharging" only after short delay, without any notification.
1065 	 */
1066 	if (battery_notification_delay_ms > 0)
1067 		msleep(battery_notification_delay_ms);
1068 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1069 		acpi_battery_refresh(battery);
1070 	acpi_battery_update(battery, false);
1071 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1072 					dev_name(&device->dev), event,
1073 					acpi_battery_present(battery));
1074 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1075 	/* acpi_battery_update could remove power_supply object */
1076 	if (old && battery->bat)
1077 		power_supply_changed(battery->bat);
1078 }
1079 
1080 static int battery_notify(struct notifier_block *nb,
1081 			       unsigned long mode, void *_unused)
1082 {
1083 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1084 						    pm_nb);
1085 	int result;
1086 
1087 	switch (mode) {
1088 	case PM_POST_HIBERNATION:
1089 	case PM_POST_SUSPEND:
1090 		if (!acpi_battery_present(battery))
1091 			return 0;
1092 
1093 		if (battery->bat) {
1094 			acpi_battery_refresh(battery);
1095 		} else {
1096 			result = acpi_battery_get_info(battery);
1097 			if (result)
1098 				return result;
1099 
1100 			result = sysfs_add_battery(battery);
1101 			if (result)
1102 				return result;
1103 		}
1104 
1105 		acpi_battery_init_alarm(battery);
1106 		acpi_battery_get_state(battery);
1107 		break;
1108 	}
1109 
1110 	return 0;
1111 }
1112 
1113 static int __init
1114 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1115 {
1116 	battery_bix_broken_package = 1;
1117 	return 0;
1118 }
1119 
1120 static int __init
1121 battery_notification_delay_quirk(const struct dmi_system_id *d)
1122 {
1123 	battery_notification_delay_ms = 1000;
1124 	return 0;
1125 }
1126 
1127 static int __init
1128 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1129 {
1130 	battery_ac_is_broken = 1;
1131 	return 0;
1132 }
1133 
1134 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1135 	{
1136 		/* NEC LZ750/LS */
1137 		.callback = battery_bix_broken_package_quirk,
1138 		.matches = {
1139 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1140 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1141 		},
1142 	},
1143 	{
1144 		/* Acer Aspire V5-573G */
1145 		.callback = battery_notification_delay_quirk,
1146 		.matches = {
1147 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1148 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1149 		},
1150 	},
1151 	{
1152 		/* Point of View mobii wintab p800w */
1153 		.callback = battery_ac_is_broken_quirk,
1154 		.matches = {
1155 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1156 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1157 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1158 			/* Above matches are too generic, add bios-date match */
1159 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1160 		},
1161 	},
1162 	{
1163 		/* Microsoft Surface Go 3 */
1164 		.callback = battery_notification_delay_quirk,
1165 		.matches = {
1166 			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1167 			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1168 		},
1169 	},
1170 	{},
1171 };
1172 
1173 /*
1174  * Some machines'(E,G Lenovo Z480) ECs are not stable
1175  * during boot up and this causes battery driver fails to be
1176  * probed due to failure of getting battery information
1177  * from EC sometimes. After several retries, the operation
1178  * may work. So add retry code here and 20ms sleep between
1179  * every retries.
1180  */
1181 static int acpi_battery_update_retry(struct acpi_battery *battery)
1182 {
1183 	int retry, ret;
1184 
1185 	for (retry = 5; retry; retry--) {
1186 		ret = acpi_battery_update(battery, false);
1187 		if (!ret)
1188 			break;
1189 
1190 		msleep(20);
1191 	}
1192 	return ret;
1193 }
1194 
1195 static int acpi_battery_add(struct acpi_device *device)
1196 {
1197 	int result = 0;
1198 	struct acpi_battery *battery = NULL;
1199 
1200 	if (!device)
1201 		return -EINVAL;
1202 
1203 	if (device->dep_unmet)
1204 		return -EPROBE_DEFER;
1205 
1206 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1207 	if (!battery)
1208 		return -ENOMEM;
1209 	battery->device = device;
1210 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1211 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1212 	device->driver_data = battery;
1213 	mutex_init(&battery->lock);
1214 	mutex_init(&battery->sysfs_lock);
1215 	if (acpi_has_method(battery->device->handle, "_BIX"))
1216 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1217 
1218 	result = acpi_battery_update_retry(battery);
1219 	if (result)
1220 		goto fail;
1221 
1222 	pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1223 		device->status.battery_present ? "present" : "absent");
1224 
1225 	battery->pm_nb.notifier_call = battery_notify;
1226 	register_pm_notifier(&battery->pm_nb);
1227 
1228 	device_init_wakeup(&device->dev, 1);
1229 
1230 	result = acpi_dev_install_notify_handler(device, ACPI_ALL_NOTIFY,
1231 						 acpi_battery_notify);
1232 	if (result)
1233 		goto fail_pm;
1234 
1235 	return 0;
1236 
1237 fail_pm:
1238 	device_init_wakeup(&device->dev, 0);
1239 	unregister_pm_notifier(&battery->pm_nb);
1240 fail:
1241 	sysfs_remove_battery(battery);
1242 	mutex_destroy(&battery->lock);
1243 	mutex_destroy(&battery->sysfs_lock);
1244 	kfree(battery);
1245 
1246 	return result;
1247 }
1248 
1249 static void acpi_battery_remove(struct acpi_device *device)
1250 {
1251 	struct acpi_battery *battery = NULL;
1252 
1253 	if (!device || !acpi_driver_data(device))
1254 		return;
1255 
1256 	battery = acpi_driver_data(device);
1257 
1258 	acpi_dev_remove_notify_handler(device, ACPI_ALL_NOTIFY,
1259 				       acpi_battery_notify);
1260 
1261 	device_init_wakeup(&device->dev, 0);
1262 	unregister_pm_notifier(&battery->pm_nb);
1263 	sysfs_remove_battery(battery);
1264 
1265 	mutex_destroy(&battery->lock);
1266 	mutex_destroy(&battery->sysfs_lock);
1267 	kfree(battery);
1268 }
1269 
1270 #ifdef CONFIG_PM_SLEEP
1271 /* this is needed to learn about changes made in suspended state */
1272 static int acpi_battery_resume(struct device *dev)
1273 {
1274 	struct acpi_battery *battery;
1275 
1276 	if (!dev)
1277 		return -EINVAL;
1278 
1279 	battery = acpi_driver_data(to_acpi_device(dev));
1280 	if (!battery)
1281 		return -EINVAL;
1282 
1283 	battery->update_time = 0;
1284 	acpi_battery_update(battery, true);
1285 	return 0;
1286 }
1287 #else
1288 #define acpi_battery_resume NULL
1289 #endif
1290 
1291 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1292 
1293 static struct acpi_driver acpi_battery_driver = {
1294 	.name = "battery",
1295 	.class = ACPI_BATTERY_CLASS,
1296 	.ids = battery_device_ids,
1297 	.ops = {
1298 		.add = acpi_battery_add,
1299 		.remove = acpi_battery_remove,
1300 		},
1301 	.drv.pm = &acpi_battery_pm,
1302 };
1303 
1304 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1305 {
1306 	int result;
1307 
1308 	if (acpi_quirk_skip_acpi_ac_and_battery())
1309 		return;
1310 
1311 	dmi_check_system(bat_dmi_table);
1312 
1313 	result = acpi_bus_register_driver(&acpi_battery_driver);
1314 	battery_driver_registered = (result == 0);
1315 }
1316 
1317 static int __init acpi_battery_init(void)
1318 {
1319 	if (acpi_disabled)
1320 		return -ENODEV;
1321 
1322 	async_cookie = async_schedule(acpi_battery_init_async, NULL);
1323 	return 0;
1324 }
1325 
1326 static void __exit acpi_battery_exit(void)
1327 {
1328 	async_synchronize_cookie(async_cookie + 1);
1329 	if (battery_driver_registered) {
1330 		acpi_bus_unregister_driver(&acpi_battery_driver);
1331 		battery_hook_exit();
1332 	}
1333 }
1334 
1335 module_init(acpi_battery_init);
1336 module_exit(acpi_battery_exit);
1337