xref: /linux/drivers/acpi/battery.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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/delay.h>
14 #include <linux/dmi.h>
15 #include <linux/jiffies.h>
16 #include <linux/kernel.h>
17 #include <linux/list.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/slab.h>
21 #include <linux/suspend.h>
22 #include <linux/types.h>
23 
24 #include <linux/unaligned.h>
25 
26 #include <linux/acpi.h>
27 #include <linux/power_supply.h>
28 
29 #include <acpi/battery.h>
30 
31 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
32 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
33 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
34 
35 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
36 
37 /* Battery power unit: 0 means mW, 1 means mA */
38 #define ACPI_BATTERY_POWER_UNIT_MA	1
39 
40 #define ACPI_BATTERY_STATE_DISCHARGING		0x1
41 #define ACPI_BATTERY_STATE_CHARGING		0x2
42 #define ACPI_BATTERY_STATE_CRITICAL		0x4
43 #define ACPI_BATTERY_STATE_CHARGE_LIMITING	0x8
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 int battery_bix_broken_package;
53 static int battery_notification_delay_ms;
54 static int battery_ac_is_broken;
55 static unsigned int cache_time = 1000;
56 module_param(cache_time, uint, 0644);
57 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
58 
59 static const struct acpi_device_id battery_device_ids[] = {
60 	{"PNP0C0A", 0},
61 
62 	/* Microsoft Surface Go 3 */
63 	{"MSHW0146", 0},
64 
65 	{"", 0},
66 };
67 
68 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
69 
70 enum {
71 	ACPI_BATTERY_ALARM_PRESENT,
72 	ACPI_BATTERY_XINFO_PRESENT,
73 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
74 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
75 	 * switches between mWh and mAh depending on whether the system
76 	 * is running on battery or not.  When mAh is the unit, most
77 	 * reported values are incorrect and need to be adjusted by
78 	 * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
79 	 * Pre-2010 and 2012 models appear to always report in mWh and
80 	 * are thus unaffected (tested with t42, t61, t500, x200, x300,
81 	 * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
82 	 *  the 2011 models that fixes the issue (tested on x220 with a
83 	 * post-1.29 BIOS), but as of Nov. 2012, no such update is
84 	 * available for the 2010 models.
85 	 */
86 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
87 	/* for batteries reporting current capacity with design capacity
88 	 * on a full charge, but showing degradation in full charge cap.
89 	 */
90 	ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
91 };
92 
93 struct acpi_battery {
94 	struct mutex update_lock;
95 	struct power_supply *bat;
96 	struct power_supply_desc bat_desc;
97 	struct acpi_device *device;
98 	struct notifier_block pm_nb;
99 	struct list_head list;
100 	unsigned long update_time;
101 	int revision;
102 	int rate_now;
103 	int capacity_now;
104 	int voltage_now;
105 	int design_capacity;
106 	int full_charge_capacity;
107 	int technology;
108 	int design_voltage;
109 	int design_capacity_warning;
110 	int design_capacity_low;
111 	int cycle_count;
112 	int measurement_accuracy;
113 	int max_sampling_time;
114 	int min_sampling_time;
115 	int max_averaging_interval;
116 	int min_averaging_interval;
117 	int capacity_granularity_1;
118 	int capacity_granularity_2;
119 	int alarm;
120 	char model_number[MAX_STRING_LENGTH];
121 	char serial_number[MAX_STRING_LENGTH];
122 	char type[MAX_STRING_LENGTH];
123 	char oem_info[MAX_STRING_LENGTH];
124 	int state;
125 	int power_unit;
126 	unsigned long flags;
127 };
128 
129 #define to_acpi_battery(x) power_supply_get_drvdata(x)
130 
131 static inline int acpi_battery_present(struct acpi_battery *battery)
132 {
133 	return battery->device->status.battery_present;
134 }
135 
136 static int acpi_battery_technology(struct acpi_battery *battery)
137 {
138 	if (!strcasecmp("NiCd", battery->type))
139 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
140 	if (!strcasecmp("NiMH", battery->type))
141 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
142 	if (!strcasecmp("LION", battery->type))
143 		return POWER_SUPPLY_TECHNOLOGY_LION;
144 	if (!strncasecmp("LI-ION", battery->type, 6))
145 		return POWER_SUPPLY_TECHNOLOGY_LION;
146 	if (!strcasecmp("LiP", battery->type))
147 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
148 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
149 }
150 
151 static int acpi_battery_get_state(struct acpi_battery *battery);
152 
153 static int acpi_battery_is_charged(struct acpi_battery *battery)
154 {
155 	/* charging, discharging, critical low or charge limited */
156 	if (battery->state != 0)
157 		return 0;
158 
159 	/* battery not reporting charge */
160 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
161 	    battery->capacity_now == 0)
162 		return 0;
163 
164 	/* good batteries update full_charge as the batteries degrade */
165 	if (battery->full_charge_capacity == battery->capacity_now)
166 		return 1;
167 
168 	/* fallback to using design values for broken batteries */
169 	if (battery->design_capacity <= battery->capacity_now)
170 		return 1;
171 
172 	/* we don't do any sort of metric based on percentages */
173 	return 0;
174 }
175 
176 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
177 {
178 	return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
179 		ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
180 		battery->full_charge_capacity < battery->design_capacity;
181 }
182 
183 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
184 {
185 	/*
186 	 * Some devices wrongly report discharging if the battery's charge level
187 	 * was above the device's start charging threshold atm the AC adapter
188 	 * was plugged in and the device thus did not start a new charge cycle.
189 	 */
190 	if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
191 	    battery->rate_now == 0)
192 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
193 
194 	return POWER_SUPPLY_STATUS_DISCHARGING;
195 }
196 
197 static int acpi_battery_get_property(struct power_supply *psy,
198 				     enum power_supply_property psp,
199 				     union power_supply_propval *val)
200 {
201 	int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
202 	struct acpi_battery *battery = to_acpi_battery(psy);
203 
204 	if (acpi_battery_present(battery)) {
205 		/* run battery update only if it is present */
206 		acpi_battery_get_state(battery);
207 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
208 		return -ENODEV;
209 	switch (psp) {
210 	case POWER_SUPPLY_PROP_STATUS:
211 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
212 			val->intval = acpi_battery_handle_discharging(battery);
213 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
214 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
215 		else if (battery->state & ACPI_BATTERY_STATE_CHARGE_LIMITING)
216 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
217 		else if (acpi_battery_is_charged(battery))
218 			val->intval = POWER_SUPPLY_STATUS_FULL;
219 		else
220 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
221 		break;
222 	case POWER_SUPPLY_PROP_PRESENT:
223 		val->intval = acpi_battery_present(battery);
224 		break;
225 	case POWER_SUPPLY_PROP_TECHNOLOGY:
226 		val->intval = acpi_battery_technology(battery);
227 		break;
228 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
229 		val->intval = battery->cycle_count;
230 		break;
231 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
232 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
233 			ret = -ENODEV;
234 		else
235 			val->intval = battery->design_voltage * 1000;
236 		break;
237 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
238 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
239 			ret = -ENODEV;
240 		else
241 			val->intval = battery->voltage_now * 1000;
242 		break;
243 	case POWER_SUPPLY_PROP_CURRENT_NOW:
244 	case POWER_SUPPLY_PROP_POWER_NOW:
245 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
246 			ret = -ENODEV;
247 		else
248 			val->intval = battery->rate_now * 1000;
249 		break;
250 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
251 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
252 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
253 			ret = -ENODEV;
254 		else
255 			val->intval = battery->design_capacity * 1000;
256 		break;
257 	case POWER_SUPPLY_PROP_CHARGE_FULL:
258 	case POWER_SUPPLY_PROP_ENERGY_FULL:
259 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
260 			ret = -ENODEV;
261 		else
262 			val->intval = battery->full_charge_capacity * 1000;
263 		break;
264 	case POWER_SUPPLY_PROP_CHARGE_NOW:
265 	case POWER_SUPPLY_PROP_ENERGY_NOW:
266 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
267 			ret = -ENODEV;
268 		else
269 			val->intval = battery->capacity_now * 1000;
270 		break;
271 	case POWER_SUPPLY_PROP_CAPACITY:
272 		if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
273 			full_capacity = battery->full_charge_capacity;
274 		else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
275 			full_capacity = battery->design_capacity;
276 
277 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
278 		    full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
279 			ret = -ENODEV;
280 		else
281 			val->intval = DIV_ROUND_CLOSEST_ULL(battery->capacity_now * 100ULL,
282 					full_capacity);
283 		break;
284 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
285 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
286 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
287 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
288 			(battery->capacity_now <= battery->alarm))
289 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
290 		else if (acpi_battery_is_charged(battery))
291 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
292 		else
293 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
294 		break;
295 	case POWER_SUPPLY_PROP_MODEL_NAME:
296 		val->strval = battery->model_number;
297 		break;
298 	case POWER_SUPPLY_PROP_MANUFACTURER:
299 		val->strval = battery->oem_info;
300 		break;
301 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
302 		val->strval = battery->serial_number;
303 		break;
304 	default:
305 		ret = -EINVAL;
306 	}
307 	return ret;
308 }
309 
310 static const enum power_supply_property charge_battery_props[] = {
311 	POWER_SUPPLY_PROP_STATUS,
312 	POWER_SUPPLY_PROP_PRESENT,
313 	POWER_SUPPLY_PROP_TECHNOLOGY,
314 	POWER_SUPPLY_PROP_CYCLE_COUNT,
315 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
316 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
317 	POWER_SUPPLY_PROP_CURRENT_NOW,
318 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
319 	POWER_SUPPLY_PROP_CHARGE_FULL,
320 	POWER_SUPPLY_PROP_CHARGE_NOW,
321 	POWER_SUPPLY_PROP_CAPACITY,
322 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
323 	POWER_SUPPLY_PROP_MODEL_NAME,
324 	POWER_SUPPLY_PROP_MANUFACTURER,
325 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
326 };
327 
328 static const enum power_supply_property charge_battery_full_cap_broken_props[] = {
329 	POWER_SUPPLY_PROP_STATUS,
330 	POWER_SUPPLY_PROP_PRESENT,
331 	POWER_SUPPLY_PROP_TECHNOLOGY,
332 	POWER_SUPPLY_PROP_CYCLE_COUNT,
333 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
334 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
335 	POWER_SUPPLY_PROP_CURRENT_NOW,
336 	POWER_SUPPLY_PROP_CHARGE_NOW,
337 	POWER_SUPPLY_PROP_MODEL_NAME,
338 	POWER_SUPPLY_PROP_MANUFACTURER,
339 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
340 };
341 
342 static const enum power_supply_property energy_battery_props[] = {
343 	POWER_SUPPLY_PROP_STATUS,
344 	POWER_SUPPLY_PROP_PRESENT,
345 	POWER_SUPPLY_PROP_TECHNOLOGY,
346 	POWER_SUPPLY_PROP_CYCLE_COUNT,
347 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
348 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
349 	POWER_SUPPLY_PROP_POWER_NOW,
350 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
351 	POWER_SUPPLY_PROP_ENERGY_FULL,
352 	POWER_SUPPLY_PROP_ENERGY_NOW,
353 	POWER_SUPPLY_PROP_CAPACITY,
354 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
355 	POWER_SUPPLY_PROP_MODEL_NAME,
356 	POWER_SUPPLY_PROP_MANUFACTURER,
357 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
358 };
359 
360 static const enum power_supply_property energy_battery_full_cap_broken_props[] = {
361 	POWER_SUPPLY_PROP_STATUS,
362 	POWER_SUPPLY_PROP_PRESENT,
363 	POWER_SUPPLY_PROP_TECHNOLOGY,
364 	POWER_SUPPLY_PROP_CYCLE_COUNT,
365 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
366 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
367 	POWER_SUPPLY_PROP_POWER_NOW,
368 	POWER_SUPPLY_PROP_ENERGY_NOW,
369 	POWER_SUPPLY_PROP_MODEL_NAME,
370 	POWER_SUPPLY_PROP_MANUFACTURER,
371 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
372 };
373 
374 /* Battery Management */
375 struct acpi_offsets {
376 	size_t offset;		/* offset inside struct acpi_sbs_battery */
377 	u8 mode;		/* int or string? */
378 };
379 
380 static const struct acpi_offsets state_offsets[] = {
381 	{offsetof(struct acpi_battery, state), 0},
382 	{offsetof(struct acpi_battery, rate_now), 0},
383 	{offsetof(struct acpi_battery, capacity_now), 0},
384 	{offsetof(struct acpi_battery, voltage_now), 0},
385 };
386 
387 static const struct acpi_offsets info_offsets[] = {
388 	{offsetof(struct acpi_battery, power_unit), 0},
389 	{offsetof(struct acpi_battery, design_capacity), 0},
390 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
391 	{offsetof(struct acpi_battery, technology), 0},
392 	{offsetof(struct acpi_battery, design_voltage), 0},
393 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
394 	{offsetof(struct acpi_battery, design_capacity_low), 0},
395 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
396 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
397 	{offsetof(struct acpi_battery, model_number), 1},
398 	{offsetof(struct acpi_battery, serial_number), 1},
399 	{offsetof(struct acpi_battery, type), 1},
400 	{offsetof(struct acpi_battery, oem_info), 1},
401 };
402 
403 static const struct acpi_offsets extended_info_offsets[] = {
404 	{offsetof(struct acpi_battery, revision), 0},
405 	{offsetof(struct acpi_battery, power_unit), 0},
406 	{offsetof(struct acpi_battery, design_capacity), 0},
407 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
408 	{offsetof(struct acpi_battery, technology), 0},
409 	{offsetof(struct acpi_battery, design_voltage), 0},
410 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
411 	{offsetof(struct acpi_battery, design_capacity_low), 0},
412 	{offsetof(struct acpi_battery, cycle_count), 0},
413 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
414 	{offsetof(struct acpi_battery, max_sampling_time), 0},
415 	{offsetof(struct acpi_battery, min_sampling_time), 0},
416 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
417 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
418 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
419 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
420 	{offsetof(struct acpi_battery, model_number), 1},
421 	{offsetof(struct acpi_battery, serial_number), 1},
422 	{offsetof(struct acpi_battery, type), 1},
423 	{offsetof(struct acpi_battery, oem_info), 1},
424 };
425 
426 static int extract_package(struct acpi_battery *battery,
427 			   union acpi_object *package,
428 			   const struct acpi_offsets *offsets, int num)
429 {
430 	int i;
431 	union acpi_object *element;
432 
433 	if (package->type != ACPI_TYPE_PACKAGE)
434 		return -EFAULT;
435 	for (i = 0; i < num; ++i) {
436 		if (package->package.count <= i)
437 			return -EFAULT;
438 		element = &package->package.elements[i];
439 		if (offsets[i].mode) {
440 			u8 *ptr = (u8 *)battery + offsets[i].offset;
441 			u32 len = MAX_STRING_LENGTH;
442 
443 			switch (element->type) {
444 			case ACPI_TYPE_BUFFER:
445 				if (len > element->buffer.length + 1)
446 					len = element->buffer.length + 1;
447 
448 				fallthrough;
449 			case ACPI_TYPE_STRING:
450 				strscpy(ptr, element->string.pointer, len);
451 
452 				break;
453 			case ACPI_TYPE_INTEGER:
454 				strscpy(ptr, (u8 *)&element->integer.value, sizeof(u64) + 1);
455 
456 				break;
457 			default:
458 				*ptr = 0; /* don't have value */
459 			}
460 		} else {
461 			int *x = (int *)((u8 *)battery + offsets[i].offset);
462 			*x = (element->type == ACPI_TYPE_INTEGER) ?
463 				element->integer.value : -1;
464 		}
465 	}
466 	return 0;
467 }
468 
469 static int acpi_battery_get_status(struct acpi_battery *battery)
470 {
471 	if (acpi_bus_get_status(battery->device)) {
472 		acpi_handle_info(battery->device->handle,
473 				 "_STA evaluation failed\n");
474 		return -ENODEV;
475 	}
476 	return 0;
477 }
478 
479 
480 static int extract_battery_info(const int use_bix,
481 			 struct acpi_battery *battery,
482 			 const struct acpi_buffer *buffer)
483 {
484 	int result = -EFAULT;
485 
486 	if (use_bix && battery_bix_broken_package)
487 		result = extract_package(battery, buffer->pointer,
488 				extended_info_offsets + 1,
489 				ARRAY_SIZE(extended_info_offsets) - 1);
490 	else if (use_bix)
491 		result = extract_package(battery, buffer->pointer,
492 				extended_info_offsets,
493 				ARRAY_SIZE(extended_info_offsets));
494 	else
495 		result = extract_package(battery, buffer->pointer,
496 				info_offsets, ARRAY_SIZE(info_offsets));
497 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
498 		battery->full_charge_capacity = battery->design_capacity;
499 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
500 	    battery->power_unit && battery->design_voltage) {
501 		battery->design_capacity = battery->design_capacity *
502 		    10000 / battery->design_voltage;
503 		battery->full_charge_capacity = battery->full_charge_capacity *
504 		    10000 / battery->design_voltage;
505 		battery->design_capacity_warning =
506 		    battery->design_capacity_warning *
507 		    10000 / battery->design_voltage;
508 		/* Curiously, design_capacity_low, unlike the rest of them,
509 		 *  is correct.
510 		 */
511 		/* capacity_granularity_* equal 1 on the systems tested, so
512 		 * it's impossible to tell if they would need an adjustment
513 		 * or not if their values were higher.
514 		 */
515 	}
516 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
517 	    battery->capacity_now > battery->full_charge_capacity)
518 		battery->capacity_now = battery->full_charge_capacity;
519 
520 	return result;
521 }
522 
523 static int acpi_battery_get_info(struct acpi_battery *battery)
524 {
525 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
526 	int use_bix;
527 	int result = -ENODEV;
528 
529 	if (!acpi_battery_present(battery))
530 		return 0;
531 
532 
533 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
534 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
535 		acpi_status status = AE_ERROR;
536 
537 		status = acpi_evaluate_object(battery->device->handle,
538 					      use_bix ? "_BIX":"_BIF",
539 					      NULL, &buffer);
540 
541 		if (ACPI_FAILURE(status)) {
542 			acpi_handle_info(battery->device->handle,
543 					 "%s evaluation failed: %s\n",
544 					 use_bix ? "_BIX":"_BIF",
545 					 acpi_format_exception(status));
546 		} else {
547 			result = extract_battery_info(use_bix,
548 						      battery,
549 						      &buffer);
550 
551 			kfree(buffer.pointer);
552 			break;
553 		}
554 	}
555 
556 	if (!result && !use_bix && xinfo)
557 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
558 
559 	return result;
560 }
561 
562 static int acpi_battery_get_state(struct acpi_battery *battery)
563 {
564 	int result = 0;
565 	acpi_status status = 0;
566 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
567 
568 	if (!acpi_battery_present(battery))
569 		return 0;
570 
571 	if (battery->update_time &&
572 	    time_before(jiffies, battery->update_time +
573 			msecs_to_jiffies(cache_time)))
574 		return 0;
575 
576 	status = acpi_evaluate_object(battery->device->handle, "_BST",
577 				      NULL, &buffer);
578 	if (ACPI_FAILURE(status)) {
579 		acpi_handle_info(battery->device->handle,
580 				 "_BST evaluation failed: %s",
581 				 acpi_format_exception(status));
582 		return -ENODEV;
583 	}
584 
585 	result = extract_package(battery, buffer.pointer,
586 				 state_offsets, ARRAY_SIZE(state_offsets));
587 	battery->update_time = jiffies;
588 	kfree(buffer.pointer);
589 
590 	/* For buggy DSDTs that report negative 16-bit values for either
591 	 * charging or discharging current and/or report 0 as 65536
592 	 * due to bad math.
593 	 */
594 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
595 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
596 		(s16)(battery->rate_now) < 0) {
597 		battery->rate_now = abs((s16)battery->rate_now);
598 		pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
599 	}
600 
601 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
602 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
603 		battery->capacity_now = (battery->capacity_now *
604 				battery->full_charge_capacity) / 100;
605 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
606 	    battery->power_unit && battery->design_voltage) {
607 		battery->capacity_now = battery->capacity_now *
608 		    10000 / battery->design_voltage;
609 	}
610 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
611 	    battery->capacity_now > battery->full_charge_capacity)
612 		battery->capacity_now = battery->full_charge_capacity;
613 
614 	return result;
615 }
616 
617 static int acpi_battery_set_alarm(struct acpi_battery *battery)
618 {
619 	acpi_status status = 0;
620 
621 	if (!acpi_battery_present(battery) ||
622 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
623 		return -ENODEV;
624 
625 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
626 					    battery->alarm);
627 	if (ACPI_FAILURE(status))
628 		return -ENODEV;
629 
630 	acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
631 			  battery->alarm);
632 
633 	return 0;
634 }
635 
636 static int acpi_battery_init_alarm(struct acpi_battery *battery)
637 {
638 	/* See if alarms are supported, and if so, set default */
639 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
640 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
641 		return 0;
642 	}
643 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
644 	if (!battery->alarm)
645 		battery->alarm = battery->design_capacity_warning;
646 	return acpi_battery_set_alarm(battery);
647 }
648 
649 static ssize_t acpi_battery_alarm_show(struct device *dev,
650 					struct device_attribute *attr,
651 					char *buf)
652 {
653 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
654 
655 	return sysfs_emit(buf, "%d\n", battery->alarm * 1000);
656 }
657 
658 static ssize_t acpi_battery_alarm_store(struct device *dev,
659 					struct device_attribute *attr,
660 					const char *buf, size_t count)
661 {
662 	unsigned long x;
663 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
664 
665 	if (sscanf(buf, "%lu\n", &x) == 1)
666 		battery->alarm = x/1000;
667 	if (acpi_battery_present(battery))
668 		acpi_battery_set_alarm(battery);
669 	return count;
670 }
671 
672 static struct device_attribute alarm_attr = {
673 	.attr = {.name = "alarm", .mode = 0644},
674 	.show = acpi_battery_alarm_show,
675 	.store = acpi_battery_alarm_store,
676 };
677 
678 static struct attribute *acpi_battery_attrs[] = {
679 	&alarm_attr.attr,
680 	NULL
681 };
682 ATTRIBUTE_GROUPS(acpi_battery);
683 
684 /*
685  * The Battery Hooking API
686  *
687  * This API is used inside other drivers that need to expose
688  * platform-specific behaviour within the generic driver in a
689  * generic way.
690  *
691  */
692 
693 static LIST_HEAD(acpi_battery_list);
694 static LIST_HEAD(battery_hook_list);
695 static DEFINE_MUTEX(hook_mutex);
696 
697 static void battery_hook_unregister_unlocked(struct acpi_battery_hook *hook)
698 {
699 	struct acpi_battery *battery;
700 
701 	/*
702 	 * In order to remove a hook, we first need to
703 	 * de-register all the batteries that are registered.
704 	 */
705 	list_for_each_entry(battery, &acpi_battery_list, list) {
706 		if (!hook->remove_battery(battery->bat, hook))
707 			power_supply_changed(battery->bat);
708 	}
709 	list_del_init(&hook->list);
710 
711 	pr_info("hook unregistered: %s\n", hook->name);
712 }
713 
714 void battery_hook_unregister(struct acpi_battery_hook *hook)
715 {
716 	mutex_lock(&hook_mutex);
717 	/*
718 	 * Ignore already unregistered battery hooks. This might happen
719 	 * if a battery hook was previously unloaded due to an error when
720 	 * adding a new battery.
721 	 */
722 	if (!list_empty(&hook->list))
723 		battery_hook_unregister_unlocked(hook);
724 
725 	mutex_unlock(&hook_mutex);
726 }
727 EXPORT_SYMBOL_GPL(battery_hook_unregister);
728 
729 void battery_hook_register(struct acpi_battery_hook *hook)
730 {
731 	struct acpi_battery *battery;
732 
733 	mutex_lock(&hook_mutex);
734 	list_add(&hook->list, &battery_hook_list);
735 	/*
736 	 * Now that the driver is registered, we need
737 	 * to notify the hook that a battery is available
738 	 * for each battery, so that the driver may add
739 	 * its attributes.
740 	 */
741 	list_for_each_entry(battery, &acpi_battery_list, list) {
742 		if (hook->add_battery(battery->bat, hook)) {
743 			/*
744 			 * If a add-battery returns non-zero,
745 			 * the registration of the hook has failed,
746 			 * and we will not add it to the list of loaded
747 			 * hooks.
748 			 */
749 			pr_err("hook failed to load: %s", hook->name);
750 			battery_hook_unregister_unlocked(hook);
751 			goto end;
752 		}
753 
754 		power_supply_changed(battery->bat);
755 	}
756 	pr_info("new hook: %s\n", hook->name);
757 end:
758 	mutex_unlock(&hook_mutex);
759 }
760 EXPORT_SYMBOL_GPL(battery_hook_register);
761 
762 static void devm_battery_hook_unregister(void *data)
763 {
764 	struct acpi_battery_hook *hook = data;
765 
766 	battery_hook_unregister(hook);
767 }
768 
769 int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook)
770 {
771 	battery_hook_register(hook);
772 
773 	return devm_add_action_or_reset(dev, devm_battery_hook_unregister, hook);
774 }
775 EXPORT_SYMBOL_GPL(devm_battery_hook_register);
776 
777 /*
778  * This function gets called right after the battery sysfs
779  * attributes have been added, so that the drivers that
780  * define custom sysfs attributes can add their own.
781  */
782 static void battery_hook_add_battery(struct acpi_battery *battery)
783 {
784 	struct acpi_battery_hook *hook_node, *tmp;
785 
786 	mutex_lock(&hook_mutex);
787 	INIT_LIST_HEAD(&battery->list);
788 	list_add(&battery->list, &acpi_battery_list);
789 	/*
790 	 * Since we added a new battery to the list, we need to
791 	 * iterate over the hooks and call add_battery for each
792 	 * hook that was registered. This usually happens
793 	 * when a battery gets hotplugged or initialized
794 	 * during the battery module initialization.
795 	 */
796 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
797 		if (hook_node->add_battery(battery->bat, hook_node)) {
798 			/*
799 			 * The notification of the hook has failed, to
800 			 * prevent further errors we will unload the hook.
801 			 */
802 			pr_err("error in hook, unloading: %s",
803 					hook_node->name);
804 			battery_hook_unregister_unlocked(hook_node);
805 		}
806 	}
807 	mutex_unlock(&hook_mutex);
808 }
809 
810 static void battery_hook_remove_battery(struct acpi_battery *battery)
811 {
812 	struct acpi_battery_hook *hook;
813 
814 	mutex_lock(&hook_mutex);
815 	/*
816 	 * Before removing the hook, we need to remove all
817 	 * custom attributes from the battery.
818 	 */
819 	list_for_each_entry(hook, &battery_hook_list, list) {
820 		hook->remove_battery(battery->bat, hook);
821 	}
822 	/* Then, just remove the battery from the list */
823 	list_del(&battery->list);
824 	mutex_unlock(&hook_mutex);
825 }
826 
827 static void __exit battery_hook_exit(void)
828 {
829 	struct acpi_battery_hook *hook;
830 	struct acpi_battery_hook *ptr;
831 	/*
832 	 * At this point, the acpi_bus_unregister_driver()
833 	 * has called remove for all batteries. We just
834 	 * need to remove the hooks.
835 	 */
836 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
837 		battery_hook_unregister(hook);
838 	}
839 	mutex_destroy(&hook_mutex);
840 }
841 
842 static int sysfs_add_battery(struct acpi_battery *battery)
843 {
844 	struct power_supply_config psy_cfg = {
845 		.drv_data = battery,
846 		.attr_grp = acpi_battery_groups,
847 		.no_wakeup_source = true,
848 	};
849 	bool full_cap_broken = false;
850 
851 	if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
852 	    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
853 		full_cap_broken = true;
854 
855 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
856 		if (full_cap_broken) {
857 			battery->bat_desc.properties =
858 			    charge_battery_full_cap_broken_props;
859 			battery->bat_desc.num_properties =
860 			    ARRAY_SIZE(charge_battery_full_cap_broken_props);
861 		} else {
862 			battery->bat_desc.properties = charge_battery_props;
863 			battery->bat_desc.num_properties =
864 			    ARRAY_SIZE(charge_battery_props);
865 		}
866 	} else {
867 		if (full_cap_broken) {
868 			battery->bat_desc.properties =
869 			    energy_battery_full_cap_broken_props;
870 			battery->bat_desc.num_properties =
871 			    ARRAY_SIZE(energy_battery_full_cap_broken_props);
872 		} else {
873 			battery->bat_desc.properties = energy_battery_props;
874 			battery->bat_desc.num_properties =
875 			    ARRAY_SIZE(energy_battery_props);
876 		}
877 	}
878 
879 	battery->bat_desc.name = acpi_device_bid(battery->device);
880 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
881 	battery->bat_desc.get_property = acpi_battery_get_property;
882 
883 	battery->bat = power_supply_register(&battery->device->dev,
884 				&battery->bat_desc, &psy_cfg);
885 
886 	if (IS_ERR(battery->bat)) {
887 		int result = PTR_ERR(battery->bat);
888 
889 		battery->bat = NULL;
890 		return result;
891 	}
892 	battery_hook_add_battery(battery);
893 	return 0;
894 }
895 
896 static void sysfs_remove_battery(struct acpi_battery *battery)
897 {
898 	if (!battery->bat)
899 		return;
900 
901 	battery_hook_remove_battery(battery);
902 	power_supply_unregister(battery->bat);
903 	battery->bat = NULL;
904 }
905 
906 static void find_battery(const struct dmi_header *dm, void *private)
907 {
908 	struct acpi_battery *battery = (struct acpi_battery *)private;
909 	/* Note: the hardcoded offsets below have been extracted from
910 	 * the source code of dmidecode.
911 	 */
912 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
913 		const u8 *dmi_data = (const u8 *)(dm + 1);
914 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
915 
916 		if (dm->length >= 18)
917 			dmi_capacity *= dmi_data[17];
918 		if (battery->design_capacity * battery->design_voltage / 1000
919 		    != dmi_capacity &&
920 		    battery->design_capacity * 10 == dmi_capacity)
921 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
922 				&battery->flags);
923 	}
924 }
925 
926 /*
927  * According to the ACPI spec, some kinds of primary batteries can
928  * report percentage battery remaining capacity directly to OS.
929  * In this case, it reports the Last Full Charged Capacity == 100
930  * and BatteryPresentRate == 0xFFFFFFFF.
931  *
932  * Now we found some battery reports percentage remaining capacity
933  * even if it's rechargeable.
934  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
935  *
936  * Handle this correctly so that they won't break userspace.
937  */
938 static void acpi_battery_quirks(struct acpi_battery *battery)
939 {
940 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
941 		return;
942 
943 	if (battery->full_charge_capacity == 100 &&
944 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
945 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
946 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
947 		battery->full_charge_capacity = battery->design_capacity;
948 		battery->capacity_now = (battery->capacity_now *
949 				battery->full_charge_capacity) / 100;
950 	}
951 
952 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
953 		return;
954 
955 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
956 		const char *s;
957 
958 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
959 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
960 			dmi_walk(find_battery, battery);
961 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
962 				     &battery->flags) &&
963 			    battery->design_voltage) {
964 				battery->design_capacity =
965 				    battery->design_capacity *
966 				    10000 / battery->design_voltage;
967 				battery->full_charge_capacity =
968 				    battery->full_charge_capacity *
969 				    10000 / battery->design_voltage;
970 				battery->design_capacity_warning =
971 				    battery->design_capacity_warning *
972 				    10000 / battery->design_voltage;
973 				battery->capacity_now = battery->capacity_now *
974 				    10000 / battery->design_voltage;
975 			}
976 		}
977 	}
978 
979 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
980 		return;
981 
982 	if (acpi_battery_is_degraded(battery) &&
983 	    battery->capacity_now > battery->full_charge_capacity) {
984 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
985 		battery->capacity_now = battery->full_charge_capacity;
986 	}
987 }
988 
989 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
990 {
991 	int result = acpi_battery_get_status(battery);
992 
993 	if (result)
994 		return result;
995 
996 	if (!acpi_battery_present(battery)) {
997 		sysfs_remove_battery(battery);
998 		battery->update_time = 0;
999 		return 0;
1000 	}
1001 
1002 	if (resume)
1003 		return 0;
1004 
1005 	if (!battery->update_time) {
1006 		result = acpi_battery_get_info(battery);
1007 		if (result)
1008 			return result;
1009 		acpi_battery_init_alarm(battery);
1010 	}
1011 
1012 	result = acpi_battery_get_state(battery);
1013 	if (result)
1014 		return result;
1015 	acpi_battery_quirks(battery);
1016 
1017 	if (!battery->bat) {
1018 		result = sysfs_add_battery(battery);
1019 		if (result)
1020 			return result;
1021 	}
1022 
1023 	/*
1024 	 * Wakeup the system if battery is critical low
1025 	 * or lower than the alarm level
1026 	 */
1027 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1028 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1029 	     (battery->capacity_now <= battery->alarm)))
1030 		acpi_pm_wakeup_event(&battery->device->dev);
1031 
1032 	return result;
1033 }
1034 
1035 static void acpi_battery_refresh(struct acpi_battery *battery)
1036 {
1037 	int power_unit;
1038 
1039 	if (!battery->bat)
1040 		return;
1041 
1042 	power_unit = battery->power_unit;
1043 
1044 	acpi_battery_get_info(battery);
1045 
1046 	if (power_unit == battery->power_unit)
1047 		return;
1048 
1049 	/* The battery has changed its reporting units. */
1050 	sysfs_remove_battery(battery);
1051 	sysfs_add_battery(battery);
1052 }
1053 
1054 /* Driver Interface */
1055 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
1056 {
1057 	struct acpi_device *device = data;
1058 	struct acpi_battery *battery = acpi_driver_data(device);
1059 	struct power_supply *old;
1060 
1061 	if (!battery)
1062 		return;
1063 
1064 	guard(mutex)(&battery->update_lock);
1065 
1066 	old = battery->bat;
1067 	/*
1068 	 * On Acer Aspire V5-573G notifications are sometimes triggered too
1069 	 * early. For example, when AC is unplugged and notification is
1070 	 * triggered, battery state is still reported as "Full", and changes to
1071 	 * "Discharging" only after short delay, without any notification.
1072 	 */
1073 	if (battery_notification_delay_ms > 0)
1074 		msleep(battery_notification_delay_ms);
1075 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1076 		acpi_battery_refresh(battery);
1077 	acpi_battery_update(battery, false);
1078 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1079 					dev_name(&device->dev), event,
1080 					acpi_battery_present(battery));
1081 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1082 	/* acpi_battery_update could remove power_supply object */
1083 	if (old && battery->bat)
1084 		power_supply_changed(battery->bat);
1085 }
1086 
1087 static int battery_notify(struct notifier_block *nb,
1088 			  unsigned long mode, void *_unused)
1089 {
1090 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1091 						    pm_nb);
1092 
1093 	if (mode == PM_POST_SUSPEND || mode == PM_POST_HIBERNATION) {
1094 		guard(mutex)(&battery->update_lock);
1095 
1096 		if (!acpi_battery_present(battery))
1097 			return 0;
1098 
1099 		if (battery->bat) {
1100 			acpi_battery_refresh(battery);
1101 		} else {
1102 			int result;
1103 
1104 			result = acpi_battery_get_info(battery);
1105 			if (result)
1106 				return result;
1107 
1108 			result = sysfs_add_battery(battery);
1109 			if (result)
1110 				return result;
1111 		}
1112 
1113 		acpi_battery_init_alarm(battery);
1114 		acpi_battery_get_state(battery);
1115 	}
1116 
1117 	return 0;
1118 }
1119 
1120 static int __init
1121 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1122 {
1123 	battery_bix_broken_package = 1;
1124 	return 0;
1125 }
1126 
1127 static int __init
1128 battery_notification_delay_quirk(const struct dmi_system_id *d)
1129 {
1130 	battery_notification_delay_ms = 1000;
1131 	return 0;
1132 }
1133 
1134 static int __init
1135 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1136 {
1137 	battery_ac_is_broken = 1;
1138 	return 0;
1139 }
1140 
1141 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1142 	{
1143 		/* NEC LZ750/LS */
1144 		.callback = battery_bix_broken_package_quirk,
1145 		.matches = {
1146 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1147 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1148 		},
1149 	},
1150 	{
1151 		/* Acer Aspire V5-573G */
1152 		.callback = battery_notification_delay_quirk,
1153 		.matches = {
1154 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1155 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1156 		},
1157 	},
1158 	{
1159 		/* Point of View mobii wintab p800w */
1160 		.callback = battery_ac_is_broken_quirk,
1161 		.matches = {
1162 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1163 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1164 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1165 			/* Above matches are too generic, add bios-date match */
1166 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1167 		},
1168 	},
1169 	{
1170 		/* Microsoft Surface Go 3 */
1171 		.callback = battery_notification_delay_quirk,
1172 		.matches = {
1173 			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1174 			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1175 		},
1176 	},
1177 	{},
1178 };
1179 
1180 /*
1181  * Some machines'(E,G Lenovo Z480) ECs are not stable
1182  * during boot up and this causes battery driver fails to be
1183  * probed due to failure of getting battery information
1184  * from EC sometimes. After several retries, the operation
1185  * may work. So add retry code here and 20ms sleep between
1186  * every retries.
1187  */
1188 static int acpi_battery_update_retry(struct acpi_battery *battery)
1189 {
1190 	int retry, ret;
1191 
1192 	guard(mutex)(&battery->update_lock);
1193 
1194 	for (retry = 5; retry; retry--) {
1195 		ret = acpi_battery_update(battery, false);
1196 		if (!ret)
1197 			break;
1198 
1199 		msleep(20);
1200 	}
1201 	return ret;
1202 }
1203 
1204 static void sysfs_battery_cleanup(struct acpi_battery *battery)
1205 {
1206 	guard(mutex)(&battery->update_lock);
1207 
1208 	sysfs_remove_battery(battery);
1209 }
1210 
1211 static int acpi_battery_add(struct acpi_device *device)
1212 {
1213 	int result = 0;
1214 	struct acpi_battery *battery;
1215 
1216 	if (!device)
1217 		return -EINVAL;
1218 
1219 	if (device->dep_unmet)
1220 		return -EPROBE_DEFER;
1221 
1222 	battery = devm_kzalloc(&device->dev, sizeof(*battery), GFP_KERNEL);
1223 	if (!battery)
1224 		return -ENOMEM;
1225 	battery->device = device;
1226 	strscpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1227 	strscpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1228 	device->driver_data = battery;
1229 
1230 	result = devm_mutex_init(&device->dev, &battery->update_lock);
1231 	if (result)
1232 		return result;
1233 
1234 	if (acpi_has_method(battery->device->handle, "_BIX"))
1235 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1236 
1237 	result = acpi_battery_update_retry(battery);
1238 	if (result)
1239 		goto fail;
1240 
1241 	pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1242 		device->status.battery_present ? "present" : "absent");
1243 
1244 	battery->pm_nb.notifier_call = battery_notify;
1245 	result = register_pm_notifier(&battery->pm_nb);
1246 	if (result)
1247 		goto fail;
1248 
1249 	device_init_wakeup(&device->dev, 1);
1250 
1251 	result = acpi_dev_install_notify_handler(device, ACPI_ALL_NOTIFY,
1252 						 acpi_battery_notify, device);
1253 	if (result)
1254 		goto fail_pm;
1255 
1256 	return 0;
1257 
1258 fail_pm:
1259 	device_init_wakeup(&device->dev, 0);
1260 	unregister_pm_notifier(&battery->pm_nb);
1261 fail:
1262 	sysfs_battery_cleanup(battery);
1263 
1264 	return result;
1265 }
1266 
1267 static void acpi_battery_remove(struct acpi_device *device)
1268 {
1269 	struct acpi_battery *battery;
1270 
1271 	if (!device || !acpi_driver_data(device))
1272 		return;
1273 
1274 	battery = acpi_driver_data(device);
1275 
1276 	acpi_dev_remove_notify_handler(device, ACPI_ALL_NOTIFY,
1277 				       acpi_battery_notify);
1278 
1279 	device_init_wakeup(&device->dev, 0);
1280 	unregister_pm_notifier(&battery->pm_nb);
1281 
1282 	guard(mutex)(&battery->update_lock);
1283 
1284 	sysfs_remove_battery(battery);
1285 }
1286 
1287 /* this is needed to learn about changes made in suspended state */
1288 static int acpi_battery_resume(struct device *dev)
1289 {
1290 	struct acpi_battery *battery;
1291 
1292 	if (!dev)
1293 		return -EINVAL;
1294 
1295 	battery = acpi_driver_data(to_acpi_device(dev));
1296 	if (!battery)
1297 		return -EINVAL;
1298 
1299 	battery->update_time = 0;
1300 
1301 	guard(mutex)(&battery->update_lock);
1302 
1303 	acpi_battery_update(battery, true);
1304 	return 0;
1305 }
1306 
1307 static DEFINE_SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1308 
1309 static struct acpi_driver acpi_battery_driver = {
1310 	.name = "battery",
1311 	.class = ACPI_BATTERY_CLASS,
1312 	.ids = battery_device_ids,
1313 	.ops = {
1314 		.add = acpi_battery_add,
1315 		.remove = acpi_battery_remove,
1316 		},
1317 	.drv.pm = pm_sleep_ptr(&acpi_battery_pm),
1318 	.drv.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1319 };
1320 
1321 static int __init acpi_battery_init(void)
1322 {
1323 	if (acpi_disabled || acpi_quirk_skip_acpi_ac_and_battery())
1324 		return -ENODEV;
1325 
1326 	dmi_check_system(bat_dmi_table);
1327 
1328 	return acpi_bus_register_driver(&acpi_battery_driver);
1329 }
1330 
1331 static void __exit acpi_battery_exit(void)
1332 {
1333 	acpi_bus_unregister_driver(&acpi_battery_driver);
1334 	battery_hook_exit();
1335 }
1336 
1337 module_init(acpi_battery_init);
1338 module_exit(acpi_battery_exit);
1339