xref: /linux/drivers/acpi/battery.c (revision 21af603b6509e1e2297de5c159317639477dcbf3)
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/ctype.h>
14 #include <linux/delay.h>
15 #include <linux/dmi.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/kfifo.h>
19 #include <linux/list.h>
20 #include <linux/lockdep.h>
21 #include <linux/module.h>
22 #include <linux/mutex.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/suspend.h>
26 #include <linux/types.h>
27 #include <linux/workqueue.h>
28 
29 #include <linux/unaligned.h>
30 
31 #include <linux/acpi.h>
32 #include <linux/power_supply.h>
33 
34 #include <acpi/battery.h>
35 
36 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
37 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
38 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
39 
40 /* Battery power unit: 0 means mW, 1 means mA */
41 #define ACPI_BATTERY_POWER_UNIT_MA	1
42 
43 #define ACPI_BATTERY_STATE_DISCHARGING		0x1
44 #define ACPI_BATTERY_STATE_CHARGING		0x2
45 #define ACPI_BATTERY_STATE_CRITICAL		0x4
46 #define ACPI_BATTERY_STATE_CHARGE_LIMITING	0x8
47 
48 #define MAX_STRING_LENGTH	64
49 
50 #define MAX_QUEUED_EVENTS	16
51 #define NOTIF_MERGING_MS	10
52 
53 MODULE_AUTHOR("Paul Diefenbaugh");
54 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
55 MODULE_DESCRIPTION("ACPI Battery Driver");
56 MODULE_LICENSE("GPL");
57 
58 static int battery_bix_broken_package;
59 static int battery_notification_delay_ms;
60 static int battery_ac_is_broken;
61 static unsigned int cache_time = 1000;
62 module_param(cache_time, uint, 0644);
63 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
64 
65 static const struct acpi_device_id battery_device_ids[] = {
66 	{"PNP0C0A", 0},
67 
68 	/* Microsoft Surface Go 3 */
69 	{"MSHW0146", 0},
70 
71 	{"", 0},
72 };
73 
74 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
75 
76 enum {
77 	ACPI_BATTERY_ALARM_PRESENT,
78 	ACPI_BATTERY_XINFO_PRESENT,
79 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
80 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
81 	 * switches between mWh and mAh depending on whether the system
82 	 * is running on battery or not.  When mAh is the unit, most
83 	 * reported values are incorrect and need to be adjusted by
84 	 * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
85 	 * Pre-2010 and 2012 models appear to always report in mWh and
86 	 * are thus unaffected (tested with t42, t61, t500, x200, x300,
87 	 * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
88 	 *  the 2011 models that fixes the issue (tested on x220 with a
89 	 * post-1.29 BIOS), but as of Nov. 2012, no such update is
90 	 * available for the 2010 models.
91 	 */
92 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
93 	/* for batteries reporting current capacity with design capacity
94 	 * on a full charge, but showing degradation in full charge cap.
95 	 */
96 	ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
97 };
98 
99 struct acpi_battery {
100 	struct mutex update_lock;
101 	struct power_supply *bat;
102 	struct power_supply_desc bat_desc;
103 	struct acpi_device *device;
104 	struct device *phys_dev;
105 	struct kfifo acpi_notif_fifo;
106 	struct delayed_work acpi_notif_dwork;
107 	struct notifier_block pm_nb;
108 	struct list_head list;
109 	unsigned long flags;
110 
111 	struct mutex property_lock; /* Protects properties below. */
112 	unsigned long update_time;
113 	int revision;
114 	int rate_now;
115 	int capacity_now;
116 	int voltage_now;
117 	int design_capacity;
118 	int full_charge_capacity;
119 	int technology;
120 	int design_voltage;
121 	int design_capacity_warning;
122 	int design_capacity_low;
123 	int cycle_count;
124 	int measurement_accuracy;
125 	int max_sampling_time;
126 	int min_sampling_time;
127 	int max_averaging_interval;
128 	int min_averaging_interval;
129 	int capacity_granularity_1;
130 	int capacity_granularity_2;
131 	int alarm;
132 	char model_number[MAX_STRING_LENGTH];
133 	char serial_number[MAX_STRING_LENGTH];
134 	char type[MAX_STRING_LENGTH];
135 	char oem_info[MAX_STRING_LENGTH];
136 	int state;
137 	int power_unit;
138 };
139 
140 #define to_acpi_battery(x) power_supply_get_drvdata(x)
141 
142 static inline int acpi_battery_present(struct acpi_battery *battery)
143 {
144 	return battery->device->status.battery_present;
145 }
146 
147 static int acpi_battery_technology(struct acpi_battery *battery)
148 {
149 	if (!strcasecmp("NiCd", battery->type))
150 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
151 	if (!strcasecmp("NiMH", battery->type))
152 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
153 	if (!strcasecmp("LION", battery->type))
154 		return POWER_SUPPLY_TECHNOLOGY_LION;
155 	if (!strncasecmp("LI-ION", battery->type, 6))
156 		return POWER_SUPPLY_TECHNOLOGY_LION;
157 	if (!strcasecmp("LiP", battery->type))
158 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
159 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
160 }
161 
162 static int acpi_battery_get_state(struct acpi_battery *battery);
163 
164 static bool acpi_battery_is_full(struct acpi_battery *battery)
165 {
166 	/* battery not reporting charge */
167 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
168 	    battery->capacity_now == 0)
169 		return false;
170 
171 	/* good batteries update full_charge as the batteries degrade */
172 	if (battery->full_charge_capacity == battery->capacity_now)
173 		return true;
174 
175 	/* fallback to using design values for broken batteries */
176 	return battery->design_capacity <= battery->capacity_now;
177 }
178 
179 static int acpi_battery_is_charged(struct acpi_battery *battery)
180 {
181 	/* charging, discharging, critical low or charge limited */
182 	if (battery->state != 0)
183 		return 0;
184 
185 	return acpi_battery_is_full(battery);
186 }
187 
188 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
189 {
190 	return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
191 		ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
192 		battery->full_charge_capacity < battery->design_capacity;
193 }
194 
195 static int acpi_battery_get_property(struct power_supply *psy,
196 				     enum power_supply_property psp,
197 				     union power_supply_propval *val)
198 {
199 	int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
200 	struct acpi_battery *battery = to_acpi_battery(psy);
201 
202 	/* run battery update only if it is present */
203 	if (!acpi_battery_present(battery)) {
204 		switch (psp) {
205 		case POWER_SUPPLY_PROP_PRESENT:
206 			val->intval = 0;
207 			return 0;
208 		default:
209 			return -ENODEV;
210 		}
211 	}
212 
213 	mutex_lock(&battery->property_lock);
214 
215 	acpi_battery_get_state(battery);
216 
217 	switch (psp) {
218 	case POWER_SUPPLY_PROP_STATUS:
219 		/*
220 		 * Some devices wrongly report discharging if the battery's charge level
221 		 * was above the device's start charging threshold atm the AC adapter
222 		 * was plugged in and the device thus did not start a new charge cycle.
223 		 */
224 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
225 			if (battery->rate_now != 0) {
226 				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
227 			} else if (battery_ac_is_broken) {
228 				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
229 			} else {
230 				mutex_unlock(&battery->property_lock);
231 
232 				val->intval = power_supply_is_system_supplied()
233 					? POWER_SUPPLY_STATUS_NOT_CHARGING
234 					: POWER_SUPPLY_STATUS_DISCHARGING;
235 				return 0;
236 			}
237 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
238 			/* Check the rate and capacity to validate the status. */
239 			if (!acpi_battery_is_full(battery) ||
240 			    (battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
241 			     battery->rate_now > 0)) {
242 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
243 			} else {
244 				/* Full and zero rate. */
245 				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
246 			}
247 		else if (battery->state & ACPI_BATTERY_STATE_CHARGE_LIMITING)
248 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
249 		else if (acpi_battery_is_charged(battery))
250 			val->intval = POWER_SUPPLY_STATUS_FULL;
251 		else
252 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
253 		break;
254 	case POWER_SUPPLY_PROP_PRESENT:
255 		val->intval = acpi_battery_present(battery);
256 		break;
257 	case POWER_SUPPLY_PROP_TECHNOLOGY:
258 		val->intval = acpi_battery_technology(battery);
259 		break;
260 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
261 		val->intval = battery->cycle_count;
262 		break;
263 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
264 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
265 			ret = -ENODEV;
266 		else
267 			val->intval = battery->design_voltage * 1000;
268 		break;
269 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
270 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
271 			ret = -ENODEV;
272 		else
273 			val->intval = battery->voltage_now * 1000;
274 		break;
275 	case POWER_SUPPLY_PROP_CURRENT_NOW:
276 	case POWER_SUPPLY_PROP_POWER_NOW:
277 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
278 			ret = -ENODEV;
279 		else
280 			val->intval = battery->rate_now * 1000;
281 		break;
282 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
283 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
284 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
285 			ret = -ENODEV;
286 		else
287 			val->intval = battery->design_capacity * 1000;
288 		break;
289 	case POWER_SUPPLY_PROP_CHARGE_FULL:
290 	case POWER_SUPPLY_PROP_ENERGY_FULL:
291 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
292 			ret = -ENODEV;
293 		else
294 			val->intval = battery->full_charge_capacity * 1000;
295 		break;
296 	case POWER_SUPPLY_PROP_CHARGE_NOW:
297 	case POWER_SUPPLY_PROP_ENERGY_NOW:
298 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
299 			ret = -ENODEV;
300 		else
301 			val->intval = battery->capacity_now * 1000;
302 		break;
303 	case POWER_SUPPLY_PROP_CAPACITY:
304 		if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
305 			full_capacity = battery->full_charge_capacity;
306 		else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
307 			full_capacity = battery->design_capacity;
308 
309 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
310 		    full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
311 			ret = -ENODEV;
312 		else
313 			val->intval = DIV_ROUND_CLOSEST_ULL(battery->capacity_now * 100ULL,
314 					full_capacity);
315 		break;
316 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
317 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
318 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
319 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
320 			(battery->capacity_now <= battery->alarm))
321 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
322 		else if (acpi_battery_is_charged(battery))
323 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
324 		else
325 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
326 		break;
327 	case POWER_SUPPLY_PROP_MODEL_NAME:
328 		val->strval = battery->model_number;
329 		break;
330 	case POWER_SUPPLY_PROP_MANUFACTURER:
331 		val->strval = battery->oem_info;
332 		break;
333 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
334 		val->strval = battery->serial_number;
335 		break;
336 	default:
337 		ret = -EINVAL;
338 	}
339 
340 	mutex_unlock(&battery->property_lock);
341 	return ret;
342 }
343 
344 /* For devices supporting the _BIX ACPI control method */
345 
346 static const enum power_supply_property charge_battery_extended_props[] = {
347 	POWER_SUPPLY_PROP_STATUS,
348 	POWER_SUPPLY_PROP_PRESENT,
349 	POWER_SUPPLY_PROP_TECHNOLOGY,
350 	POWER_SUPPLY_PROP_CYCLE_COUNT,
351 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
352 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
353 	POWER_SUPPLY_PROP_CURRENT_NOW,
354 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
355 	POWER_SUPPLY_PROP_CHARGE_FULL,
356 	POWER_SUPPLY_PROP_CHARGE_NOW,
357 	POWER_SUPPLY_PROP_CAPACITY,
358 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
359 	POWER_SUPPLY_PROP_MODEL_NAME,
360 	POWER_SUPPLY_PROP_MANUFACTURER,
361 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
362 };
363 
364 static const enum power_supply_property charge_battery_full_cap_broken_extended_props[] = {
365 	POWER_SUPPLY_PROP_STATUS,
366 	POWER_SUPPLY_PROP_PRESENT,
367 	POWER_SUPPLY_PROP_TECHNOLOGY,
368 	POWER_SUPPLY_PROP_CYCLE_COUNT,
369 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
370 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
371 	POWER_SUPPLY_PROP_CURRENT_NOW,
372 	POWER_SUPPLY_PROP_CHARGE_NOW,
373 	POWER_SUPPLY_PROP_MODEL_NAME,
374 	POWER_SUPPLY_PROP_MANUFACTURER,
375 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
376 };
377 
378 static const enum power_supply_property energy_battery_extended_props[] = {
379 	POWER_SUPPLY_PROP_STATUS,
380 	POWER_SUPPLY_PROP_PRESENT,
381 	POWER_SUPPLY_PROP_TECHNOLOGY,
382 	POWER_SUPPLY_PROP_CYCLE_COUNT,
383 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
384 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
385 	POWER_SUPPLY_PROP_POWER_NOW,
386 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
387 	POWER_SUPPLY_PROP_ENERGY_FULL,
388 	POWER_SUPPLY_PROP_ENERGY_NOW,
389 	POWER_SUPPLY_PROP_CAPACITY,
390 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
391 	POWER_SUPPLY_PROP_MODEL_NAME,
392 	POWER_SUPPLY_PROP_MANUFACTURER,
393 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
394 };
395 
396 static const enum power_supply_property energy_battery_full_cap_broken_extended_props[] = {
397 	POWER_SUPPLY_PROP_STATUS,
398 	POWER_SUPPLY_PROP_PRESENT,
399 	POWER_SUPPLY_PROP_TECHNOLOGY,
400 	POWER_SUPPLY_PROP_CYCLE_COUNT,
401 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
402 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
403 	POWER_SUPPLY_PROP_POWER_NOW,
404 	POWER_SUPPLY_PROP_ENERGY_NOW,
405 	POWER_SUPPLY_PROP_MODEL_NAME,
406 	POWER_SUPPLY_PROP_MANUFACTURER,
407 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
408 };
409 
410 /* For devices supporting only the _BIF ACPI control method */
411 
412 static const enum power_supply_property charge_battery_props[] = {
413 	POWER_SUPPLY_PROP_STATUS,
414 	POWER_SUPPLY_PROP_PRESENT,
415 	POWER_SUPPLY_PROP_TECHNOLOGY,
416 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
417 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
418 	POWER_SUPPLY_PROP_CURRENT_NOW,
419 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
420 	POWER_SUPPLY_PROP_CHARGE_FULL,
421 	POWER_SUPPLY_PROP_CHARGE_NOW,
422 	POWER_SUPPLY_PROP_CAPACITY,
423 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
424 	POWER_SUPPLY_PROP_MODEL_NAME,
425 	POWER_SUPPLY_PROP_MANUFACTURER,
426 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
427 };
428 
429 static const enum power_supply_property charge_battery_full_cap_broken_props[] = {
430 	POWER_SUPPLY_PROP_STATUS,
431 	POWER_SUPPLY_PROP_PRESENT,
432 	POWER_SUPPLY_PROP_TECHNOLOGY,
433 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
434 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
435 	POWER_SUPPLY_PROP_CURRENT_NOW,
436 	POWER_SUPPLY_PROP_CHARGE_NOW,
437 	POWER_SUPPLY_PROP_MODEL_NAME,
438 	POWER_SUPPLY_PROP_MANUFACTURER,
439 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
440 };
441 
442 static const enum power_supply_property energy_battery_props[] = {
443 	POWER_SUPPLY_PROP_STATUS,
444 	POWER_SUPPLY_PROP_PRESENT,
445 	POWER_SUPPLY_PROP_TECHNOLOGY,
446 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
447 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
448 	POWER_SUPPLY_PROP_POWER_NOW,
449 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
450 	POWER_SUPPLY_PROP_ENERGY_FULL,
451 	POWER_SUPPLY_PROP_ENERGY_NOW,
452 	POWER_SUPPLY_PROP_CAPACITY,
453 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
454 	POWER_SUPPLY_PROP_MODEL_NAME,
455 	POWER_SUPPLY_PROP_MANUFACTURER,
456 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
457 };
458 
459 static const enum power_supply_property energy_battery_full_cap_broken_props[] = {
460 	POWER_SUPPLY_PROP_STATUS,
461 	POWER_SUPPLY_PROP_PRESENT,
462 	POWER_SUPPLY_PROP_TECHNOLOGY,
463 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
464 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
465 	POWER_SUPPLY_PROP_POWER_NOW,
466 	POWER_SUPPLY_PROP_ENERGY_NOW,
467 	POWER_SUPPLY_PROP_MODEL_NAME,
468 	POWER_SUPPLY_PROP_MANUFACTURER,
469 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
470 };
471 
472 /* Battery Management */
473 struct acpi_offsets {
474 	size_t offset;		/* offset inside struct acpi_sbs_battery */
475 	u8 mode;		/* int or string? */
476 };
477 
478 static const struct acpi_offsets state_offsets[] = {
479 	{offsetof(struct acpi_battery, state), 0},
480 	{offsetof(struct acpi_battery, rate_now), 0},
481 	{offsetof(struct acpi_battery, capacity_now), 0},
482 	{offsetof(struct acpi_battery, voltage_now), 0},
483 };
484 
485 static const struct acpi_offsets info_offsets[] = {
486 	{offsetof(struct acpi_battery, power_unit), 0},
487 	{offsetof(struct acpi_battery, design_capacity), 0},
488 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
489 	{offsetof(struct acpi_battery, technology), 0},
490 	{offsetof(struct acpi_battery, design_voltage), 0},
491 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
492 	{offsetof(struct acpi_battery, design_capacity_low), 0},
493 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
494 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
495 	{offsetof(struct acpi_battery, model_number), 1},
496 	{offsetof(struct acpi_battery, serial_number), 1},
497 	{offsetof(struct acpi_battery, type), 1},
498 	{offsetof(struct acpi_battery, oem_info), 1},
499 };
500 
501 static const struct acpi_offsets extended_info_offsets[] = {
502 	{offsetof(struct acpi_battery, revision), 0},
503 	{offsetof(struct acpi_battery, power_unit), 0},
504 	{offsetof(struct acpi_battery, design_capacity), 0},
505 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
506 	{offsetof(struct acpi_battery, technology), 0},
507 	{offsetof(struct acpi_battery, design_voltage), 0},
508 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
509 	{offsetof(struct acpi_battery, design_capacity_low), 0},
510 	{offsetof(struct acpi_battery, cycle_count), 0},
511 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
512 	{offsetof(struct acpi_battery, max_sampling_time), 0},
513 	{offsetof(struct acpi_battery, min_sampling_time), 0},
514 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
515 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
516 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
517 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
518 	{offsetof(struct acpi_battery, model_number), 1},
519 	{offsetof(struct acpi_battery, serial_number), 1},
520 	{offsetof(struct acpi_battery, type), 1},
521 	{offsetof(struct acpi_battery, oem_info), 1},
522 };
523 
524 static int extract_package(struct acpi_battery *battery,
525 			   union acpi_object *package,
526 			   const struct acpi_offsets *offsets, int num)
527 {
528 	int i;
529 	union acpi_object *element;
530 
531 	if (package->type != ACPI_TYPE_PACKAGE)
532 		return -EFAULT;
533 	for (i = 0; i < num; ++i) {
534 		if (package->package.count <= i)
535 			return -EFAULT;
536 		element = &package->package.elements[i];
537 		if (offsets[i].mode) {
538 			u8 *ptr = (u8 *)battery + offsets[i].offset;
539 			u32 len = MAX_STRING_LENGTH;
540 
541 			switch (element->type) {
542 			case ACPI_TYPE_BUFFER:
543 				if (len > element->buffer.length + 1)
544 					len = element->buffer.length + 1;
545 
546 				fallthrough;
547 			case ACPI_TYPE_STRING:
548 				strscpy(ptr, element->string.pointer, len);
549 
550 				break;
551 			case ACPI_TYPE_INTEGER:
552 				strscpy(ptr, (u8 *)&element->integer.value, sizeof(u64) + 1);
553 
554 				break;
555 			default:
556 				*ptr = 0; /* don't have value */
557 			}
558 		} else {
559 			int *x = (int *)((u8 *)battery + offsets[i].offset);
560 			*x = (element->type == ACPI_TYPE_INTEGER) ?
561 				element->integer.value : -1;
562 		}
563 	}
564 	return 0;
565 }
566 
567 static int acpi_battery_get_status(struct acpi_battery *battery)
568 {
569 	if (acpi_bus_get_status(battery->device)) {
570 		acpi_handle_info(battery->device->handle,
571 				 "_STA evaluation failed\n");
572 		return -ENODEV;
573 	}
574 	return 0;
575 }
576 
577 static void acpi_battery_clean_unprintable_chars(char *str, size_t length)
578 {
579 	for (unsigned int i = 0; i < length; i++) {
580 		if (!isascii(str[i]) || !isprint(str[i])) {
581 			str[i] = '\0';
582 			break;
583 		}
584 	}
585 }
586 
587 static int extract_battery_info(const int use_bix,
588 			 struct acpi_battery *battery,
589 			 const struct acpi_buffer *buffer)
590 {
591 	int result = -EFAULT;
592 
593 	if (use_bix && battery_bix_broken_package)
594 		result = extract_package(battery, buffer->pointer,
595 				extended_info_offsets + 1,
596 				ARRAY_SIZE(extended_info_offsets) - 1);
597 	else if (use_bix)
598 		result = extract_package(battery, buffer->pointer,
599 				extended_info_offsets,
600 				ARRAY_SIZE(extended_info_offsets));
601 	else
602 		result = extract_package(battery, buffer->pointer,
603 				info_offsets, ARRAY_SIZE(info_offsets));
604 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
605 		battery->full_charge_capacity = battery->design_capacity;
606 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
607 	    battery->power_unit && battery->design_voltage) {
608 		battery->design_capacity = battery->design_capacity *
609 		    10000 / battery->design_voltage;
610 		battery->full_charge_capacity = battery->full_charge_capacity *
611 		    10000 / battery->design_voltage;
612 		battery->design_capacity_warning =
613 		    battery->design_capacity_warning *
614 		    10000 / battery->design_voltage;
615 		/* Curiously, design_capacity_low, unlike the rest of them,
616 		 *  is correct.
617 		 */
618 		/* capacity_granularity_* equal 1 on the systems tested, so
619 		 * it's impossible to tell if they would need an adjustment
620 		 * or not if their values were higher.
621 		 */
622 	}
623 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
624 	    battery->capacity_now > battery->full_charge_capacity)
625 		battery->capacity_now = battery->full_charge_capacity;
626 
627 	if (!result)
628 		acpi_battery_clean_unprintable_chars(battery->model_number,
629 					ARRAY_SIZE(battery->model_number));
630 
631 	return result;
632 }
633 
634 static int acpi_battery_get_info(struct acpi_battery *battery)
635 {
636 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
637 	int use_bix;
638 	int result = -ENODEV;
639 
640 	lockdep_assert_held(&battery->property_lock);
641 
642 	if (!acpi_battery_present(battery))
643 		return 0;
644 
645 
646 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
647 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
648 		acpi_status status = AE_ERROR;
649 
650 		status = acpi_evaluate_object(battery->device->handle,
651 					      use_bix ? "_BIX":"_BIF",
652 					      NULL, &buffer);
653 
654 		if (ACPI_FAILURE(status)) {
655 			acpi_handle_info(battery->device->handle,
656 					 "%s evaluation failed: %s\n",
657 					 use_bix ? "_BIX":"_BIF",
658 					 acpi_format_exception(status));
659 		} else {
660 			result = extract_battery_info(use_bix,
661 						      battery,
662 						      &buffer);
663 
664 			kfree(buffer.pointer);
665 			break;
666 		}
667 	}
668 
669 	if (!result && !use_bix && xinfo)
670 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
671 
672 	return result;
673 }
674 
675 static int acpi_battery_get_state(struct acpi_battery *battery)
676 {
677 	int result = 0;
678 	acpi_status status = 0;
679 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
680 
681 	lockdep_assert_held(&battery->property_lock);
682 
683 	if (!acpi_battery_present(battery))
684 		return 0;
685 
686 	if (battery->update_time &&
687 	    time_before(jiffies, battery->update_time +
688 			msecs_to_jiffies(cache_time)))
689 		return 0;
690 
691 	status = acpi_evaluate_object(battery->device->handle, "_BST",
692 				      NULL, &buffer);
693 	if (ACPI_FAILURE(status)) {
694 		acpi_handle_info(battery->device->handle,
695 				 "_BST evaluation failed: %s",
696 				 acpi_format_exception(status));
697 		return -ENODEV;
698 	}
699 
700 	result = extract_package(battery, buffer.pointer,
701 				 state_offsets, ARRAY_SIZE(state_offsets));
702 	battery->update_time = jiffies;
703 	kfree(buffer.pointer);
704 
705 	/* For buggy DSDTs that report negative 16-bit values for either
706 	 * charging or discharging current and/or report 0 as 65536
707 	 * due to bad math.
708 	 */
709 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
710 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
711 		(s16)(battery->rate_now) < 0) {
712 		battery->rate_now = abs((s16)battery->rate_now);
713 		pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
714 	}
715 
716 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
717 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
718 		battery->capacity_now = (battery->capacity_now *
719 				battery->full_charge_capacity) / 100;
720 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
721 	    battery->power_unit && battery->design_voltage) {
722 		battery->capacity_now = battery->capacity_now *
723 		    10000 / battery->design_voltage;
724 	}
725 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
726 	    battery->capacity_now > battery->full_charge_capacity)
727 		battery->capacity_now = battery->full_charge_capacity;
728 
729 	return result;
730 }
731 
732 static int acpi_battery_set_alarm(struct acpi_battery *battery)
733 {
734 	acpi_status status = 0;
735 
736 	lockdep_assert_held(&battery->property_lock);
737 
738 	if (!acpi_battery_present(battery) ||
739 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
740 		return -ENODEV;
741 
742 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
743 					    battery->alarm);
744 	if (ACPI_FAILURE(status))
745 		return -ENODEV;
746 
747 	acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
748 			  battery->alarm);
749 
750 	return 0;
751 }
752 
753 static int acpi_battery_init_alarm(struct acpi_battery *battery)
754 {
755 	lockdep_assert_held(&battery->property_lock);
756 
757 	/* See if alarms are supported, and if so, set default */
758 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
759 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
760 		return 0;
761 	}
762 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
763 	if (!battery->alarm)
764 		battery->alarm = battery->design_capacity_warning;
765 	return acpi_battery_set_alarm(battery);
766 }
767 
768 static ssize_t acpi_battery_alarm_show(struct device *dev,
769 					struct device_attribute *attr,
770 					char *buf)
771 {
772 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
773 
774 	guard(mutex)(&battery->property_lock);
775 
776 	return sysfs_emit(buf, "%d\n", battery->alarm * 1000);
777 }
778 
779 static ssize_t acpi_battery_alarm_store(struct device *dev,
780 					struct device_attribute *attr,
781 					const char *buf, size_t count)
782 {
783 	unsigned long x;
784 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
785 	int err;
786 
787 	err = kstrtoul(buf, 10, &x);
788 	if (err)
789 		return err;
790 
791 	guard(mutex)(&battery->property_lock);
792 
793 	battery->alarm = x / 1000;
794 	if (acpi_battery_present(battery))
795 		acpi_battery_set_alarm(battery);
796 	return count;
797 }
798 
799 static struct device_attribute alarm_attr = {
800 	.attr = {.name = "alarm", .mode = 0644},
801 	.show = acpi_battery_alarm_show,
802 	.store = acpi_battery_alarm_store,
803 };
804 
805 static struct attribute *acpi_battery_attrs[] = {
806 	&alarm_attr.attr,
807 	NULL
808 };
809 ATTRIBUTE_GROUPS(acpi_battery);
810 
811 /*
812  * The Battery Hooking API
813  *
814  * This API is used inside other drivers that need to expose
815  * platform-specific behaviour within the generic driver in a
816  * generic way.
817  *
818  */
819 
820 static LIST_HEAD(acpi_battery_list);
821 static LIST_HEAD(battery_hook_list);
822 static DEFINE_MUTEX(hook_mutex);
823 
824 static void battery_hook_unregister_unlocked(struct acpi_battery_hook *hook)
825 {
826 	struct acpi_battery *battery;
827 
828 	/*
829 	 * In order to remove a hook, we first need to
830 	 * de-register all the batteries that are registered.
831 	 */
832 	list_for_each_entry(battery, &acpi_battery_list, list) {
833 		if (!hook->remove_battery(battery->bat, hook))
834 			power_supply_changed(battery->bat);
835 	}
836 	list_del_init(&hook->list);
837 
838 	pr_info("hook unregistered: %s\n", hook->name);
839 }
840 
841 void battery_hook_unregister(struct acpi_battery_hook *hook)
842 {
843 	mutex_lock(&hook_mutex);
844 	/*
845 	 * Ignore already unregistered battery hooks. This might happen
846 	 * if a battery hook was previously unloaded due to an error when
847 	 * adding a new battery.
848 	 */
849 	if (!list_empty(&hook->list))
850 		battery_hook_unregister_unlocked(hook);
851 
852 	mutex_unlock(&hook_mutex);
853 }
854 EXPORT_SYMBOL_GPL(battery_hook_unregister);
855 
856 void battery_hook_register(struct acpi_battery_hook *hook)
857 {
858 	struct acpi_battery *battery;
859 
860 	mutex_lock(&hook_mutex);
861 	list_add(&hook->list, &battery_hook_list);
862 	/*
863 	 * Now that the driver is registered, we need
864 	 * to notify the hook that a battery is available
865 	 * for each battery, so that the driver may add
866 	 * its attributes.
867 	 */
868 	list_for_each_entry(battery, &acpi_battery_list, list) {
869 		if (hook->add_battery(battery->bat, hook)) {
870 			/*
871 			 * If a add-battery returns non-zero,
872 			 * the registration of the hook has failed,
873 			 * and we will not add it to the list of loaded
874 			 * hooks.
875 			 */
876 			pr_err("hook failed to load: %s", hook->name);
877 			battery_hook_unregister_unlocked(hook);
878 			goto end;
879 		}
880 
881 		power_supply_changed(battery->bat);
882 	}
883 	pr_info("new hook: %s\n", hook->name);
884 end:
885 	mutex_unlock(&hook_mutex);
886 }
887 EXPORT_SYMBOL_GPL(battery_hook_register);
888 
889 static void devm_battery_hook_unregister(void *data)
890 {
891 	struct acpi_battery_hook *hook = data;
892 
893 	battery_hook_unregister(hook);
894 }
895 
896 int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook)
897 {
898 	battery_hook_register(hook);
899 
900 	return devm_add_action_or_reset(dev, devm_battery_hook_unregister, hook);
901 }
902 EXPORT_SYMBOL_GPL(devm_battery_hook_register);
903 
904 /*
905  * This function gets called right after the battery sysfs
906  * attributes have been added, so that the drivers that
907  * define custom sysfs attributes can add their own.
908  */
909 static void battery_hook_add_battery(struct acpi_battery *battery)
910 {
911 	struct acpi_battery_hook *hook_node, *tmp;
912 
913 	mutex_lock(&hook_mutex);
914 	INIT_LIST_HEAD(&battery->list);
915 	list_add(&battery->list, &acpi_battery_list);
916 	/*
917 	 * Since we added a new battery to the list, we need to
918 	 * iterate over the hooks and call add_battery for each
919 	 * hook that was registered. This usually happens
920 	 * when a battery gets hotplugged or initialized
921 	 * during the battery module initialization.
922 	 */
923 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
924 		if (hook_node->add_battery(battery->bat, hook_node)) {
925 			/*
926 			 * The notification of the hook has failed, to
927 			 * prevent further errors we will unload the hook.
928 			 */
929 			pr_err("error in hook, unloading: %s",
930 					hook_node->name);
931 			battery_hook_unregister_unlocked(hook_node);
932 		}
933 	}
934 	mutex_unlock(&hook_mutex);
935 }
936 
937 static void battery_hook_remove_battery(struct acpi_battery *battery)
938 {
939 	struct acpi_battery_hook *hook;
940 
941 	mutex_lock(&hook_mutex);
942 	/*
943 	 * Before removing the hook, we need to remove all
944 	 * custom attributes from the battery.
945 	 */
946 	list_for_each_entry(hook, &battery_hook_list, list) {
947 		hook->remove_battery(battery->bat, hook);
948 	}
949 	/* Then, just remove the battery from the list */
950 	list_del(&battery->list);
951 	mutex_unlock(&hook_mutex);
952 }
953 
954 static void __exit battery_hook_exit(void)
955 {
956 	struct acpi_battery_hook *hook;
957 	struct acpi_battery_hook *ptr;
958 	/*
959 	 * At this point, the acpi_bus_unregister_driver()
960 	 * has called remove for all batteries. We just
961 	 * need to remove the hooks.
962 	 */
963 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
964 		battery_hook_unregister(hook);
965 	}
966 	mutex_destroy(&hook_mutex);
967 }
968 
969 static int sysfs_add_battery(struct acpi_battery *battery)
970 {
971 	bool extended_info_available = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
972 	struct power_supply_config psy_cfg = {
973 		.drv_data = battery,
974 		.attr_grp = acpi_battery_groups,
975 		.no_wakeup_source = true,
976 	};
977 	bool full_cap_broken = false;
978 	int power_unit;
979 
980 	scoped_guard(mutex, &battery->property_lock) {
981 		power_unit = battery->power_unit;
982 
983 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
984 		    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
985 			full_cap_broken = true;
986 	}
987 
988 	if (power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
989 		if (full_cap_broken) {
990 			if (extended_info_available) {
991 				battery->bat_desc.properties =
992 					charge_battery_full_cap_broken_extended_props;
993 				battery->bat_desc.num_properties =
994 					ARRAY_SIZE(charge_battery_full_cap_broken_extended_props);
995 			} else {
996 				battery->bat_desc.properties =
997 					charge_battery_full_cap_broken_props;
998 				battery->bat_desc.num_properties =
999 					ARRAY_SIZE(charge_battery_full_cap_broken_props);
1000 			}
1001 		} else {
1002 			if (extended_info_available) {
1003 				battery->bat_desc.properties =
1004 					charge_battery_extended_props;
1005 				battery->bat_desc.num_properties =
1006 					ARRAY_SIZE(charge_battery_extended_props);
1007 			} else {
1008 				battery->bat_desc.properties =
1009 					charge_battery_props;
1010 				battery->bat_desc.num_properties =
1011 					ARRAY_SIZE(charge_battery_props);
1012 			}
1013 		}
1014 	} else {
1015 		if (full_cap_broken) {
1016 			if (extended_info_available) {
1017 				battery->bat_desc.properties =
1018 					energy_battery_full_cap_broken_extended_props;
1019 				battery->bat_desc.num_properties =
1020 					ARRAY_SIZE(energy_battery_full_cap_broken_extended_props);
1021 			} else {
1022 				battery->bat_desc.properties =
1023 					energy_battery_full_cap_broken_props;
1024 				battery->bat_desc.num_properties =
1025 					ARRAY_SIZE(energy_battery_full_cap_broken_props);
1026 			}
1027 		} else {
1028 			if (extended_info_available) {
1029 				battery->bat_desc.properties =
1030 					energy_battery_extended_props;
1031 				battery->bat_desc.num_properties =
1032 					ARRAY_SIZE(energy_battery_extended_props);
1033 			} else {
1034 				battery->bat_desc.properties =
1035 					energy_battery_props;
1036 				battery->bat_desc.num_properties =
1037 					ARRAY_SIZE(energy_battery_props);
1038 			}
1039 		}
1040 	}
1041 
1042 	battery->bat_desc.name = acpi_device_bid(battery->device);
1043 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
1044 	battery->bat_desc.get_property = acpi_battery_get_property;
1045 
1046 	battery->bat = power_supply_register(&battery->device->dev,
1047 				&battery->bat_desc, &psy_cfg);
1048 
1049 	if (IS_ERR(battery->bat)) {
1050 		int result = PTR_ERR(battery->bat);
1051 
1052 		battery->bat = NULL;
1053 		return result;
1054 	}
1055 	battery_hook_add_battery(battery);
1056 	return 0;
1057 }
1058 
1059 static void sysfs_remove_battery(struct acpi_battery *battery)
1060 {
1061 	if (!battery->bat)
1062 		return;
1063 
1064 	battery_hook_remove_battery(battery);
1065 	power_supply_unregister(battery->bat);
1066 	battery->bat = NULL;
1067 }
1068 
1069 static void find_battery(const struct dmi_header *dm, void *private)
1070 {
1071 	struct acpi_battery *battery = (struct acpi_battery *)private;
1072 
1073 	lockdep_assert_held(&battery->property_lock);
1074 
1075 	/* Note: the hardcoded offsets below have been extracted from
1076 	 * the source code of dmidecode.
1077 	 */
1078 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
1079 		const u8 *dmi_data = (const u8 *)(dm + 1);
1080 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
1081 
1082 		if (dm->length >= 18)
1083 			dmi_capacity *= dmi_data[17];
1084 		if (battery->design_capacity * battery->design_voltage / 1000
1085 		    != dmi_capacity &&
1086 		    battery->design_capacity * 10 == dmi_capacity)
1087 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
1088 				&battery->flags);
1089 	}
1090 }
1091 
1092 /*
1093  * According to the ACPI spec, some kinds of primary batteries can
1094  * report percentage battery remaining capacity directly to OS.
1095  * In this case, it reports the Last Full Charged Capacity == 100
1096  * and BatteryPresentRate == 0xFFFFFFFF.
1097  *
1098  * Now we found some battery reports percentage remaining capacity
1099  * even if it's rechargeable.
1100  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
1101  *
1102  * Handle this correctly so that they won't break userspace.
1103  */
1104 static void acpi_battery_quirks(struct acpi_battery *battery)
1105 {
1106 	lockdep_assert_held(&battery->property_lock);
1107 
1108 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
1109 		return;
1110 
1111 	if (battery->full_charge_capacity == 100 &&
1112 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
1113 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
1114 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
1115 		battery->full_charge_capacity = battery->design_capacity;
1116 		battery->capacity_now = (battery->capacity_now *
1117 				battery->full_charge_capacity) / 100;
1118 	}
1119 
1120 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
1121 		return;
1122 
1123 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
1124 		const char *s;
1125 
1126 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
1127 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
1128 			dmi_walk(find_battery, battery);
1129 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
1130 				     &battery->flags) &&
1131 			    battery->design_voltage) {
1132 				battery->design_capacity =
1133 				    battery->design_capacity *
1134 				    10000 / battery->design_voltage;
1135 				battery->full_charge_capacity =
1136 				    battery->full_charge_capacity *
1137 				    10000 / battery->design_voltage;
1138 				battery->design_capacity_warning =
1139 				    battery->design_capacity_warning *
1140 				    10000 / battery->design_voltage;
1141 				battery->capacity_now = battery->capacity_now *
1142 				    10000 / battery->design_voltage;
1143 			}
1144 		}
1145 	}
1146 
1147 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
1148 		return;
1149 
1150 	if (acpi_battery_is_degraded(battery) &&
1151 	    battery->capacity_now > battery->full_charge_capacity) {
1152 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
1153 		battery->capacity_now = battery->full_charge_capacity;
1154 	}
1155 }
1156 
1157 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
1158 {
1159 	int result = acpi_battery_get_status(battery);
1160 	bool wakeup;
1161 
1162 	if (result)
1163 		return result;
1164 
1165 	if (!acpi_battery_present(battery)) {
1166 		sysfs_remove_battery(battery);
1167 		scoped_guard(mutex, &battery->property_lock)
1168 			battery->update_time = 0;
1169 		return 0;
1170 	}
1171 
1172 	if (resume)
1173 		return 0;
1174 
1175 	scoped_guard(mutex, &battery->property_lock) {
1176 		if (!battery->update_time) {
1177 			result = acpi_battery_get_info(battery);
1178 			if (result)
1179 				return result;
1180 			acpi_battery_init_alarm(battery);
1181 		}
1182 
1183 		result = acpi_battery_get_state(battery);
1184 		if (result)
1185 			return result;
1186 		acpi_battery_quirks(battery);
1187 
1188 		wakeup = ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1189 			  (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1190 			   (battery->capacity_now <= battery->alarm)));
1191 	}
1192 
1193 	if (!battery->bat) {
1194 		result = sysfs_add_battery(battery);
1195 		if (result)
1196 			return result;
1197 	}
1198 
1199 	/*
1200 	 * Wakeup the system if battery is critical low
1201 	 * or lower than the alarm level
1202 	 */
1203 	if (wakeup)
1204 		acpi_pm_wakeup_event(battery->phys_dev);
1205 
1206 	return result;
1207 }
1208 
1209 static void acpi_battery_refresh(struct acpi_battery *battery)
1210 {
1211 	int power_unit;
1212 
1213 	if (!battery->bat)
1214 		return;
1215 
1216 	scoped_guard(mutex, &battery->property_lock) {
1217 		power_unit = battery->power_unit;
1218 
1219 		acpi_battery_get_info(battery);
1220 
1221 		if (power_unit == battery->power_unit)
1222 			return;
1223 	}
1224 
1225 	/* The battery has changed its reporting units. */
1226 	sysfs_remove_battery(battery);
1227 	sysfs_add_battery(battery);
1228 }
1229 
1230 /* Driver Interface */
1231 static void acpi_battery_notification_worker(struct work_struct *work)
1232 {
1233 	struct acpi_battery *battery = container_of(work, struct acpi_battery,
1234 						    acpi_notif_dwork.work);
1235 	struct acpi_device *device = battery->device;
1236 	u32 events[MAX_QUEUED_EVENTS];
1237 	struct power_supply *old;
1238 	unsigned int count, i;
1239 
1240 	guard(mutex)(&battery->update_lock);
1241 
1242 	count = kfifo_out(&battery->acpi_notif_fifo, events, sizeof(events));
1243 	count /= sizeof(events[0]);
1244 	if (!count)
1245 		return;
1246 
1247 	pr_debug("merged %u battery notifications within %dms\n", count, NOTIF_MERGING_MS);
1248 
1249 	old = battery->bat;
1250 	/*
1251 	 * On Acer Aspire V5-573G notifications are sometimes triggered too
1252 	 * early. For example, when AC is unplugged and notification is
1253 	 * triggered, battery state is still reported as "Full", and changes to
1254 	 * "Discharging" only after short delay, without any notification.
1255 	 */
1256 	if (battery_notification_delay_ms > 0)
1257 		msleep(battery_notification_delay_ms);
1258 
1259 	for (i = 0; i < count; i++) {
1260 		if (events[i] == ACPI_BATTERY_NOTIFY_INFO) {
1261 			acpi_battery_refresh(battery);
1262 			break;
1263 		}
1264 	}
1265 
1266 	acpi_battery_update(battery, false);
1267 
1268 	for (i = 0; i < count; i++) {
1269 		acpi_bus_generate_netlink_event(ACPI_BATTERY_CLASS,
1270 						dev_name(&device->dev), events[i],
1271 						acpi_battery_present(battery));
1272 		acpi_notifier_call_chain(ACPI_BATTERY_CLASS, acpi_device_bid(device),
1273 					 events[i], acpi_battery_present(battery));
1274 	}
1275 
1276 	/* acpi_battery_update could remove power_supply object */
1277 	if (old && battery->bat)
1278 		power_supply_changed(battery->bat);
1279 }
1280 
1281 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
1282 {
1283 	struct acpi_battery *battery = data;
1284 
1285 	guard(mutex)(&battery->update_lock);
1286 
1287 	if (kfifo_avail(&battery->acpi_notif_fifo) >= sizeof(event)) {
1288 		kfifo_in(&battery->acpi_notif_fifo, &event, sizeof(event));
1289 		schedule_delayed_work(&battery->acpi_notif_dwork,
1290 				      msecs_to_jiffies(NOTIF_MERGING_MS));
1291 
1292 		return;
1293 	}
1294 
1295 	pr_err_ratelimited("too many battery notifications within %dms\n", NOTIF_MERGING_MS);
1296 }
1297 
1298 static int battery_notify(struct notifier_block *nb,
1299 			  unsigned long mode, void *_unused)
1300 {
1301 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1302 						    pm_nb);
1303 
1304 	if (mode == PM_POST_SUSPEND || mode == PM_POST_HIBERNATION) {
1305 		guard(mutex)(&battery->update_lock);
1306 
1307 		if (!acpi_battery_present(battery))
1308 			return 0;
1309 
1310 		if (battery->bat) {
1311 			acpi_battery_refresh(battery);
1312 		} else {
1313 			int result;
1314 
1315 			scoped_guard(mutex, &battery->property_lock) {
1316 				result = acpi_battery_get_info(battery);
1317 				if (result)
1318 					return result;
1319 			}
1320 
1321 			result = sysfs_add_battery(battery);
1322 			if (result)
1323 				return result;
1324 		}
1325 
1326 		scoped_guard(mutex, &battery->property_lock) {
1327 			acpi_battery_init_alarm(battery);
1328 			acpi_battery_get_state(battery);
1329 		}
1330 	}
1331 
1332 	return 0;
1333 }
1334 
1335 static int __init
1336 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1337 {
1338 	battery_bix_broken_package = 1;
1339 	return 0;
1340 }
1341 
1342 static int __init
1343 battery_notification_delay_quirk(const struct dmi_system_id *d)
1344 {
1345 	battery_notification_delay_ms = 1000;
1346 	return 0;
1347 }
1348 
1349 static int __init
1350 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1351 {
1352 	battery_ac_is_broken = 1;
1353 	return 0;
1354 }
1355 
1356 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1357 	{
1358 		/* NEC LZ750/LS */
1359 		.callback = battery_bix_broken_package_quirk,
1360 		.matches = {
1361 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1362 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1363 		},
1364 	},
1365 	{
1366 		/* Acer Aspire V5-573G */
1367 		.callback = battery_notification_delay_quirk,
1368 		.matches = {
1369 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1370 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1371 		},
1372 	},
1373 	{
1374 		/* Point of View mobii wintab p800w */
1375 		.callback = battery_ac_is_broken_quirk,
1376 		.matches = {
1377 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1378 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1379 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1380 			/* Above matches are too generic, add bios-date match */
1381 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1382 		},
1383 	},
1384 	{
1385 		/* Microsoft Surface Go 3 */
1386 		.callback = battery_notification_delay_quirk,
1387 		.matches = {
1388 			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1389 			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1390 		},
1391 	},
1392 	{},
1393 };
1394 
1395 static void acpi_battery_wakeup_cleanup(void *data)
1396 {
1397 	device_init_wakeup(data, false);
1398 }
1399 
1400 static int devm_acpi_battery_init_wakeup(struct device *dev)
1401 {
1402 	device_init_wakeup(dev, true);
1403 	return devm_add_action_or_reset(dev, acpi_battery_wakeup_cleanup, dev);
1404 }
1405 
1406 static void sysfs_battery_cleanup(void *data)
1407 {
1408 	struct acpi_battery *battery = data;
1409 
1410 	guard(mutex)(&battery->update_lock);
1411 
1412 	sysfs_remove_battery(battery);
1413 }
1414 
1415 /*
1416  * Some machines'(E,G Lenovo Z480) ECs are not stable
1417  * during boot up and this causes battery driver fails to be
1418  * probed due to failure of getting battery information
1419  * from EC sometimes. After several retries, the operation
1420  * may work. So add retry code here and 20ms sleep between
1421  * every retries.
1422  */
1423 static int devm_acpi_battery_update_retry(struct device *dev,
1424 					  struct acpi_battery *battery)
1425 {
1426 	int retry, ret;
1427 
1428 	ret = devm_add_action(dev, sysfs_battery_cleanup, battery);
1429 	if (ret)
1430 		return ret;
1431 
1432 	guard(mutex)(&battery->update_lock);
1433 
1434 	for (retry = 5; retry; retry--) {
1435 		ret = acpi_battery_update(battery, false);
1436 		if (!ret)
1437 			break;
1438 
1439 		msleep(20);
1440 	}
1441 	return ret;
1442 }
1443 
1444 static void acpi_battery_notify_dwork_cleanup(void *data)
1445 {
1446 	struct acpi_battery *battery = data;
1447 
1448 	cancel_delayed_work_sync(&battery->acpi_notif_dwork);
1449 	kfifo_free(&battery->acpi_notif_fifo);
1450 }
1451 
1452 static int devm_acpi_battery_init_notify_dwork(struct device *dev,
1453 					       struct acpi_battery *battery)
1454 {
1455 	int ret;
1456 
1457 	INIT_DELAYED_WORK(&battery->acpi_notif_dwork, acpi_battery_notification_worker);
1458 
1459 	ret = kfifo_alloc(&battery->acpi_notif_fifo,
1460 			  MAX_QUEUED_EVENTS * sizeof(u32), GFP_KERNEL);
1461 	if (ret)
1462 		return ret;
1463 
1464 	return devm_add_action_or_reset(dev, acpi_battery_notify_dwork_cleanup, battery);
1465 }
1466 
1467 static int acpi_battery_probe(struct platform_device *pdev)
1468 {
1469 	struct device *dev = &pdev->dev;
1470 	struct acpi_battery *battery;
1471 	struct acpi_device *device;
1472 	int result;
1473 
1474 	device = ACPI_COMPANION(dev);
1475 	if (!device)
1476 		return -ENODEV;
1477 
1478 	if (device->dep_unmet)
1479 		return -EPROBE_DEFER;
1480 
1481 	battery = devm_kzalloc(dev, sizeof(*battery), GFP_KERNEL);
1482 	if (!battery)
1483 		return -ENOMEM;
1484 
1485 	platform_set_drvdata(pdev, battery);
1486 
1487 	battery->phys_dev = &pdev->dev;
1488 	battery->device = device;
1489 
1490 	result = devm_mutex_init(dev, &battery->update_lock);
1491 	if (result)
1492 		return result;
1493 
1494 	result = devm_mutex_init(&pdev->dev, &battery->property_lock);
1495 	if (result)
1496 		return result;
1497 
1498 	if (acpi_has_method(battery->device->handle, "_BIX"))
1499 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1500 
1501 	result = devm_acpi_battery_update_retry(dev, battery);
1502 	if (result)
1503 		return result;
1504 
1505 	pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1506 		device->status.battery_present ? "present" : "absent");
1507 
1508 	result = devm_acpi_battery_init_wakeup(dev);
1509 	if (result)
1510 		return result;
1511 
1512 	result = devm_acpi_battery_init_notify_dwork(dev, battery);
1513 	if (result)
1514 		return result;
1515 
1516 	result = devm_acpi_install_notify_handler(dev, ACPI_ALL_NOTIFY,
1517 						  acpi_battery_notify, battery);
1518 	if (result)
1519 		return result;
1520 
1521 	battery->pm_nb.notifier_call = battery_notify;
1522 	return register_pm_notifier(&battery->pm_nb);
1523 }
1524 
1525 static void acpi_battery_remove(struct platform_device *pdev)
1526 {
1527 	struct acpi_battery *battery = platform_get_drvdata(pdev);
1528 
1529 	unregister_pm_notifier(&battery->pm_nb);
1530 }
1531 
1532 /* this is needed to learn about changes made in suspended state */
1533 static int acpi_battery_resume(struct device *dev)
1534 {
1535 	struct acpi_battery *battery = dev_get_drvdata(dev);
1536 
1537 	if (!battery)
1538 		return -EINVAL;
1539 
1540 	battery->update_time = 0;
1541 
1542 	guard(mutex)(&battery->update_lock);
1543 
1544 	acpi_battery_update(battery, true);
1545 	return 0;
1546 }
1547 
1548 static DEFINE_SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1549 
1550 static struct platform_driver acpi_battery_driver = {
1551 	.probe = acpi_battery_probe,
1552 	.remove = acpi_battery_remove,
1553 	.driver = {
1554 		.name = "acpi-battery",
1555 		.acpi_match_table = battery_device_ids,
1556 		.pm = pm_sleep_ptr(&acpi_battery_pm),
1557 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1558 	},
1559 };
1560 
1561 static int __init acpi_battery_init(void)
1562 {
1563 	if (acpi_disabled || acpi_quirk_skip_acpi_ac_and_battery())
1564 		return -ENODEV;
1565 
1566 	dmi_check_system(bat_dmi_table);
1567 
1568 	return platform_driver_register(&acpi_battery_driver);
1569 }
1570 
1571 static void __exit acpi_battery_exit(void)
1572 {
1573 	platform_driver_unregister(&acpi_battery_driver);
1574 	battery_hook_exit();
1575 }
1576 
1577 module_init(acpi_battery_init);
1578 module_exit(acpi_battery_exit);
1579