xref: /linux/drivers/acpi/battery.c (revision c118478665f467e57d06b2354de65974b246b82b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  battery.c - ACPI Battery Driver (Revision: 2.0)
4  *
5  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
6  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  */
10 
11 #define pr_fmt(fmt) "ACPI: battery: " fmt
12 
13 #include <linux/async.h>
14 #include <linux/delay.h>
15 #include <linux/dmi.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/suspend.h>
23 #include <linux/types.h>
24 
25 #include <asm/unaligned.h>
26 
27 #include <linux/acpi.h>
28 #include <linux/power_supply.h>
29 
30 #include <acpi/battery.h>
31 
32 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
33 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
34 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
35 
36 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
37 
38 /* Battery power unit: 0 means mW, 1 means mA */
39 #define ACPI_BATTERY_POWER_UNIT_MA	1
40 
41 #define ACPI_BATTERY_STATE_DISCHARGING		0x1
42 #define ACPI_BATTERY_STATE_CHARGING		0x2
43 #define ACPI_BATTERY_STATE_CRITICAL		0x4
44 #define ACPI_BATTERY_STATE_CHARGE_LIMITING	0x8
45 
46 #define MAX_STRING_LENGTH	64
47 
48 MODULE_AUTHOR("Paul Diefenbaugh");
49 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
50 MODULE_DESCRIPTION("ACPI Battery Driver");
51 MODULE_LICENSE("GPL");
52 
53 static async_cookie_t async_cookie;
54 static bool battery_driver_registered;
55 static int battery_bix_broken_package;
56 static int battery_notification_delay_ms;
57 static int battery_ac_is_broken;
58 static unsigned int cache_time = 1000;
59 module_param(cache_time, uint, 0644);
60 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
61 
62 static const struct acpi_device_id battery_device_ids[] = {
63 	{"PNP0C0A", 0},
64 
65 	/* Microsoft Surface Go 3 */
66 	{"MSHW0146", 0},
67 
68 	{"", 0},
69 };
70 
71 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
72 
73 enum {
74 	ACPI_BATTERY_ALARM_PRESENT,
75 	ACPI_BATTERY_XINFO_PRESENT,
76 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
77 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
78 	 * switches between mWh and mAh depending on whether the system
79 	 * is running on battery or not.  When mAh is the unit, most
80 	 * reported values are incorrect and need to be adjusted by
81 	 * 10000/design_voltage.  Verified on x201, t410, t410s, and x220.
82 	 * Pre-2010 and 2012 models appear to always report in mWh and
83 	 * are thus unaffected (tested with t42, t61, t500, x200, x300,
84 	 * and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
85 	 *  the 2011 models that fixes the issue (tested on x220 with a
86 	 * post-1.29 BIOS), but as of Nov. 2012, no such update is
87 	 * available for the 2010 models.
88 	 */
89 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
90 	/* for batteries reporting current capacity with design capacity
91 	 * on a full charge, but showing degradation in full charge cap.
92 	 */
93 	ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
94 };
95 
96 struct acpi_battery {
97 	struct mutex lock;
98 	struct mutex sysfs_lock;
99 	struct power_supply *bat;
100 	struct power_supply_desc bat_desc;
101 	struct acpi_device *device;
102 	struct notifier_block pm_nb;
103 	struct list_head list;
104 	unsigned long update_time;
105 	int revision;
106 	int rate_now;
107 	int capacity_now;
108 	int voltage_now;
109 	int design_capacity;
110 	int full_charge_capacity;
111 	int technology;
112 	int design_voltage;
113 	int design_capacity_warning;
114 	int design_capacity_low;
115 	int cycle_count;
116 	int measurement_accuracy;
117 	int max_sampling_time;
118 	int min_sampling_time;
119 	int max_averaging_interval;
120 	int min_averaging_interval;
121 	int capacity_granularity_1;
122 	int capacity_granularity_2;
123 	int alarm;
124 	char model_number[MAX_STRING_LENGTH];
125 	char serial_number[MAX_STRING_LENGTH];
126 	char type[MAX_STRING_LENGTH];
127 	char oem_info[MAX_STRING_LENGTH];
128 	int state;
129 	int power_unit;
130 	unsigned long flags;
131 };
132 
133 #define to_acpi_battery(x) power_supply_get_drvdata(x)
134 
135 static inline int acpi_battery_present(struct acpi_battery *battery)
136 {
137 	return battery->device->status.battery_present;
138 }
139 
140 static int acpi_battery_technology(struct acpi_battery *battery)
141 {
142 	if (!strcasecmp("NiCd", battery->type))
143 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
144 	if (!strcasecmp("NiMH", battery->type))
145 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
146 	if (!strcasecmp("LION", battery->type))
147 		return POWER_SUPPLY_TECHNOLOGY_LION;
148 	if (!strncasecmp("LI-ION", battery->type, 6))
149 		return POWER_SUPPLY_TECHNOLOGY_LION;
150 	if (!strcasecmp("LiP", battery->type))
151 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
152 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
153 }
154 
155 static int acpi_battery_get_state(struct acpi_battery *battery);
156 
157 static int acpi_battery_is_charged(struct acpi_battery *battery)
158 {
159 	/* charging, discharging, critical low or charge limited */
160 	if (battery->state != 0)
161 		return 0;
162 
163 	/* battery not reporting charge */
164 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
165 	    battery->capacity_now == 0)
166 		return 0;
167 
168 	/* good batteries update full_charge as the batteries degrade */
169 	if (battery->full_charge_capacity == battery->capacity_now)
170 		return 1;
171 
172 	/* fallback to using design values for broken batteries */
173 	if (battery->design_capacity <= battery->capacity_now)
174 		return 1;
175 
176 	/* we don't do any sort of metric based on percentages */
177 	return 0;
178 }
179 
180 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
181 {
182 	return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
183 		ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
184 		battery->full_charge_capacity < battery->design_capacity;
185 }
186 
187 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
188 {
189 	/*
190 	 * Some devices wrongly report discharging if the battery's charge level
191 	 * was above the device's start charging threshold atm the AC adapter
192 	 * was plugged in and the device thus did not start a new charge cycle.
193 	 */
194 	if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
195 	    battery->rate_now == 0)
196 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
197 
198 	return POWER_SUPPLY_STATUS_DISCHARGING;
199 }
200 
201 static int acpi_battery_get_property(struct power_supply *psy,
202 				     enum power_supply_property psp,
203 				     union power_supply_propval *val)
204 {
205 	int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
206 	struct acpi_battery *battery = to_acpi_battery(psy);
207 
208 	if (acpi_battery_present(battery)) {
209 		/* run battery update only if it is present */
210 		acpi_battery_get_state(battery);
211 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
212 		return -ENODEV;
213 	switch (psp) {
214 	case POWER_SUPPLY_PROP_STATUS:
215 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
216 			val->intval = acpi_battery_handle_discharging(battery);
217 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
218 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
219 		else if (battery->state & ACPI_BATTERY_STATE_CHARGE_LIMITING)
220 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
221 		else if (acpi_battery_is_charged(battery))
222 			val->intval = POWER_SUPPLY_STATUS_FULL;
223 		else
224 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
225 		break;
226 	case POWER_SUPPLY_PROP_PRESENT:
227 		val->intval = acpi_battery_present(battery);
228 		break;
229 	case POWER_SUPPLY_PROP_TECHNOLOGY:
230 		val->intval = acpi_battery_technology(battery);
231 		break;
232 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
233 		val->intval = battery->cycle_count;
234 		break;
235 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
236 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
237 			ret = -ENODEV;
238 		else
239 			val->intval = battery->design_voltage * 1000;
240 		break;
241 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
242 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
243 			ret = -ENODEV;
244 		else
245 			val->intval = battery->voltage_now * 1000;
246 		break;
247 	case POWER_SUPPLY_PROP_CURRENT_NOW:
248 	case POWER_SUPPLY_PROP_POWER_NOW:
249 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
250 			ret = -ENODEV;
251 		else
252 			val->intval = battery->rate_now * 1000;
253 		break;
254 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
255 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
256 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
257 			ret = -ENODEV;
258 		else
259 			val->intval = battery->design_capacity * 1000;
260 		break;
261 	case POWER_SUPPLY_PROP_CHARGE_FULL:
262 	case POWER_SUPPLY_PROP_ENERGY_FULL:
263 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
264 			ret = -ENODEV;
265 		else
266 			val->intval = battery->full_charge_capacity * 1000;
267 		break;
268 	case POWER_SUPPLY_PROP_CHARGE_NOW:
269 	case POWER_SUPPLY_PROP_ENERGY_NOW:
270 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
271 			ret = -ENODEV;
272 		else
273 			val->intval = battery->capacity_now * 1000;
274 		break;
275 	case POWER_SUPPLY_PROP_CAPACITY:
276 		if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
277 			full_capacity = battery->full_charge_capacity;
278 		else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
279 			full_capacity = battery->design_capacity;
280 
281 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
282 		    full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
283 			ret = -ENODEV;
284 		else
285 			val->intval = battery->capacity_now * 100/
286 					full_capacity;
287 		break;
288 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
289 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
290 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
291 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
292 			(battery->capacity_now <= battery->alarm))
293 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
294 		else if (acpi_battery_is_charged(battery))
295 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
296 		else
297 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
298 		break;
299 	case POWER_SUPPLY_PROP_MODEL_NAME:
300 		val->strval = battery->model_number;
301 		break;
302 	case POWER_SUPPLY_PROP_MANUFACTURER:
303 		val->strval = battery->oem_info;
304 		break;
305 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
306 		val->strval = battery->serial_number;
307 		break;
308 	default:
309 		ret = -EINVAL;
310 	}
311 	return ret;
312 }
313 
314 static const enum power_supply_property charge_battery_props[] = {
315 	POWER_SUPPLY_PROP_STATUS,
316 	POWER_SUPPLY_PROP_PRESENT,
317 	POWER_SUPPLY_PROP_TECHNOLOGY,
318 	POWER_SUPPLY_PROP_CYCLE_COUNT,
319 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
320 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
321 	POWER_SUPPLY_PROP_CURRENT_NOW,
322 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
323 	POWER_SUPPLY_PROP_CHARGE_FULL,
324 	POWER_SUPPLY_PROP_CHARGE_NOW,
325 	POWER_SUPPLY_PROP_CAPACITY,
326 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
327 	POWER_SUPPLY_PROP_MODEL_NAME,
328 	POWER_SUPPLY_PROP_MANUFACTURER,
329 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
330 };
331 
332 static const enum power_supply_property charge_battery_full_cap_broken_props[] = {
333 	POWER_SUPPLY_PROP_STATUS,
334 	POWER_SUPPLY_PROP_PRESENT,
335 	POWER_SUPPLY_PROP_TECHNOLOGY,
336 	POWER_SUPPLY_PROP_CYCLE_COUNT,
337 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
338 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
339 	POWER_SUPPLY_PROP_CURRENT_NOW,
340 	POWER_SUPPLY_PROP_CHARGE_NOW,
341 	POWER_SUPPLY_PROP_MODEL_NAME,
342 	POWER_SUPPLY_PROP_MANUFACTURER,
343 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
344 };
345 
346 static const enum power_supply_property energy_battery_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_POWER_NOW,
354 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
355 	POWER_SUPPLY_PROP_ENERGY_FULL,
356 	POWER_SUPPLY_PROP_ENERGY_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 energy_battery_full_cap_broken_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_POWER_NOW,
372 	POWER_SUPPLY_PROP_ENERGY_NOW,
373 	POWER_SUPPLY_PROP_MODEL_NAME,
374 	POWER_SUPPLY_PROP_MANUFACTURER,
375 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
376 };
377 
378 /* Battery Management */
379 struct acpi_offsets {
380 	size_t offset;		/* offset inside struct acpi_sbs_battery */
381 	u8 mode;		/* int or string? */
382 };
383 
384 static const struct acpi_offsets state_offsets[] = {
385 	{offsetof(struct acpi_battery, state), 0},
386 	{offsetof(struct acpi_battery, rate_now), 0},
387 	{offsetof(struct acpi_battery, capacity_now), 0},
388 	{offsetof(struct acpi_battery, voltage_now), 0},
389 };
390 
391 static const struct acpi_offsets info_offsets[] = {
392 	{offsetof(struct acpi_battery, power_unit), 0},
393 	{offsetof(struct acpi_battery, design_capacity), 0},
394 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
395 	{offsetof(struct acpi_battery, technology), 0},
396 	{offsetof(struct acpi_battery, design_voltage), 0},
397 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
398 	{offsetof(struct acpi_battery, design_capacity_low), 0},
399 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
400 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
401 	{offsetof(struct acpi_battery, model_number), 1},
402 	{offsetof(struct acpi_battery, serial_number), 1},
403 	{offsetof(struct acpi_battery, type), 1},
404 	{offsetof(struct acpi_battery, oem_info), 1},
405 };
406 
407 static const struct acpi_offsets extended_info_offsets[] = {
408 	{offsetof(struct acpi_battery, revision), 0},
409 	{offsetof(struct acpi_battery, power_unit), 0},
410 	{offsetof(struct acpi_battery, design_capacity), 0},
411 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
412 	{offsetof(struct acpi_battery, technology), 0},
413 	{offsetof(struct acpi_battery, design_voltage), 0},
414 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
415 	{offsetof(struct acpi_battery, design_capacity_low), 0},
416 	{offsetof(struct acpi_battery, cycle_count), 0},
417 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
418 	{offsetof(struct acpi_battery, max_sampling_time), 0},
419 	{offsetof(struct acpi_battery, min_sampling_time), 0},
420 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
421 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
422 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
423 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
424 	{offsetof(struct acpi_battery, model_number), 1},
425 	{offsetof(struct acpi_battery, serial_number), 1},
426 	{offsetof(struct acpi_battery, type), 1},
427 	{offsetof(struct acpi_battery, oem_info), 1},
428 };
429 
430 static int extract_package(struct acpi_battery *battery,
431 			   union acpi_object *package,
432 			   const struct acpi_offsets *offsets, int num)
433 {
434 	int i;
435 	union acpi_object *element;
436 
437 	if (package->type != ACPI_TYPE_PACKAGE)
438 		return -EFAULT;
439 	for (i = 0; i < num; ++i) {
440 		if (package->package.count <= i)
441 			return -EFAULT;
442 		element = &package->package.elements[i];
443 		if (offsets[i].mode) {
444 			u8 *ptr = (u8 *)battery + offsets[i].offset;
445 			u32 len = MAX_STRING_LENGTH;
446 
447 			switch (element->type) {
448 			case ACPI_TYPE_BUFFER:
449 				if (len > element->buffer.length + 1)
450 					len = element->buffer.length + 1;
451 
452 				fallthrough;
453 			case ACPI_TYPE_STRING:
454 				strscpy(ptr, element->string.pointer, len);
455 
456 				break;
457 			case ACPI_TYPE_INTEGER:
458 				strscpy(ptr, (u8 *)&element->integer.value, sizeof(u64) + 1);
459 
460 				break;
461 			default:
462 				*ptr = 0; /* don't have value */
463 			}
464 		} else {
465 			int *x = (int *)((u8 *)battery + offsets[i].offset);
466 			*x = (element->type == ACPI_TYPE_INTEGER) ?
467 				element->integer.value : -1;
468 		}
469 	}
470 	return 0;
471 }
472 
473 static int acpi_battery_get_status(struct acpi_battery *battery)
474 {
475 	if (acpi_bus_get_status(battery->device)) {
476 		acpi_handle_info(battery->device->handle,
477 				 "_STA evaluation failed\n");
478 		return -ENODEV;
479 	}
480 	return 0;
481 }
482 
483 
484 static int extract_battery_info(const int use_bix,
485 			 struct acpi_battery *battery,
486 			 const struct acpi_buffer *buffer)
487 {
488 	int result = -EFAULT;
489 
490 	if (use_bix && battery_bix_broken_package)
491 		result = extract_package(battery, buffer->pointer,
492 				extended_info_offsets + 1,
493 				ARRAY_SIZE(extended_info_offsets) - 1);
494 	else if (use_bix)
495 		result = extract_package(battery, buffer->pointer,
496 				extended_info_offsets,
497 				ARRAY_SIZE(extended_info_offsets));
498 	else
499 		result = extract_package(battery, buffer->pointer,
500 				info_offsets, ARRAY_SIZE(info_offsets));
501 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
502 		battery->full_charge_capacity = battery->design_capacity;
503 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
504 	    battery->power_unit && battery->design_voltage) {
505 		battery->design_capacity = battery->design_capacity *
506 		    10000 / battery->design_voltage;
507 		battery->full_charge_capacity = battery->full_charge_capacity *
508 		    10000 / battery->design_voltage;
509 		battery->design_capacity_warning =
510 		    battery->design_capacity_warning *
511 		    10000 / battery->design_voltage;
512 		/* Curiously, design_capacity_low, unlike the rest of them,
513 		 *  is correct.
514 		 */
515 		/* capacity_granularity_* equal 1 on the systems tested, so
516 		 * it's impossible to tell if they would need an adjustment
517 		 * or not if their values were higher.
518 		 */
519 	}
520 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
521 	    battery->capacity_now > battery->full_charge_capacity)
522 		battery->capacity_now = battery->full_charge_capacity;
523 
524 	return result;
525 }
526 
527 static int acpi_battery_get_info(struct acpi_battery *battery)
528 {
529 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
530 	int use_bix;
531 	int result = -ENODEV;
532 
533 	if (!acpi_battery_present(battery))
534 		return 0;
535 
536 
537 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
538 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
539 		acpi_status status = AE_ERROR;
540 
541 		mutex_lock(&battery->lock);
542 		status = acpi_evaluate_object(battery->device->handle,
543 					      use_bix ? "_BIX":"_BIF",
544 					      NULL, &buffer);
545 		mutex_unlock(&battery->lock);
546 
547 		if (ACPI_FAILURE(status)) {
548 			acpi_handle_info(battery->device->handle,
549 					 "%s evaluation failed: %s\n",
550 					 use_bix ? "_BIX":"_BIF",
551 					 acpi_format_exception(status));
552 		} else {
553 			result = extract_battery_info(use_bix,
554 						      battery,
555 						      &buffer);
556 
557 			kfree(buffer.pointer);
558 			break;
559 		}
560 	}
561 
562 	if (!result && !use_bix && xinfo)
563 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
564 
565 	return result;
566 }
567 
568 static int acpi_battery_get_state(struct acpi_battery *battery)
569 {
570 	int result = 0;
571 	acpi_status status = 0;
572 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
573 
574 	if (!acpi_battery_present(battery))
575 		return 0;
576 
577 	if (battery->update_time &&
578 	    time_before(jiffies, battery->update_time +
579 			msecs_to_jiffies(cache_time)))
580 		return 0;
581 
582 	mutex_lock(&battery->lock);
583 	status = acpi_evaluate_object(battery->device->handle, "_BST",
584 				      NULL, &buffer);
585 	mutex_unlock(&battery->lock);
586 
587 	if (ACPI_FAILURE(status)) {
588 		acpi_handle_info(battery->device->handle,
589 				 "_BST evaluation failed: %s",
590 				 acpi_format_exception(status));
591 		return -ENODEV;
592 	}
593 
594 	result = extract_package(battery, buffer.pointer,
595 				 state_offsets, ARRAY_SIZE(state_offsets));
596 	battery->update_time = jiffies;
597 	kfree(buffer.pointer);
598 
599 	/* For buggy DSDTs that report negative 16-bit values for either
600 	 * charging or discharging current and/or report 0 as 65536
601 	 * due to bad math.
602 	 */
603 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
604 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
605 		(s16)(battery->rate_now) < 0) {
606 		battery->rate_now = abs((s16)battery->rate_now);
607 		pr_warn_once(FW_BUG "(dis)charge rate invalid.\n");
608 	}
609 
610 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
611 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
612 		battery->capacity_now = (battery->capacity_now *
613 				battery->full_charge_capacity) / 100;
614 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
615 	    battery->power_unit && battery->design_voltage) {
616 		battery->capacity_now = battery->capacity_now *
617 		    10000 / battery->design_voltage;
618 	}
619 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
620 	    battery->capacity_now > battery->full_charge_capacity)
621 		battery->capacity_now = battery->full_charge_capacity;
622 
623 	return result;
624 }
625 
626 static int acpi_battery_set_alarm(struct acpi_battery *battery)
627 {
628 	acpi_status status = 0;
629 
630 	if (!acpi_battery_present(battery) ||
631 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
632 		return -ENODEV;
633 
634 	mutex_lock(&battery->lock);
635 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
636 					    battery->alarm);
637 	mutex_unlock(&battery->lock);
638 
639 	if (ACPI_FAILURE(status))
640 		return -ENODEV;
641 
642 	acpi_handle_debug(battery->device->handle, "Alarm set to %d\n",
643 			  battery->alarm);
644 
645 	return 0;
646 }
647 
648 static int acpi_battery_init_alarm(struct acpi_battery *battery)
649 {
650 	/* See if alarms are supported, and if so, set default */
651 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
652 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
653 		return 0;
654 	}
655 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
656 	if (!battery->alarm)
657 		battery->alarm = battery->design_capacity_warning;
658 	return acpi_battery_set_alarm(battery);
659 }
660 
661 static ssize_t acpi_battery_alarm_show(struct device *dev,
662 					struct device_attribute *attr,
663 					char *buf)
664 {
665 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
666 
667 	return sysfs_emit(buf, "%d\n", battery->alarm * 1000);
668 }
669 
670 static ssize_t acpi_battery_alarm_store(struct device *dev,
671 					struct device_attribute *attr,
672 					const char *buf, size_t count)
673 {
674 	unsigned long x;
675 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
676 
677 	if (sscanf(buf, "%lu\n", &x) == 1)
678 		battery->alarm = x/1000;
679 	if (acpi_battery_present(battery))
680 		acpi_battery_set_alarm(battery);
681 	return count;
682 }
683 
684 static struct device_attribute alarm_attr = {
685 	.attr = {.name = "alarm", .mode = 0644},
686 	.show = acpi_battery_alarm_show,
687 	.store = acpi_battery_alarm_store,
688 };
689 
690 static struct attribute *acpi_battery_attrs[] = {
691 	&alarm_attr.attr,
692 	NULL
693 };
694 ATTRIBUTE_GROUPS(acpi_battery);
695 
696 /*
697  * The Battery Hooking API
698  *
699  * This API is used inside other drivers that need to expose
700  * platform-specific behaviour within the generic driver in a
701  * generic way.
702  *
703  */
704 
705 static LIST_HEAD(acpi_battery_list);
706 static LIST_HEAD(battery_hook_list);
707 static DEFINE_MUTEX(hook_mutex);
708 
709 static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
710 {
711 	struct acpi_battery *battery;
712 	/*
713 	 * In order to remove a hook, we first need to
714 	 * de-register all the batteries that are registered.
715 	 */
716 	if (lock)
717 		mutex_lock(&hook_mutex);
718 	list_for_each_entry(battery, &acpi_battery_list, list) {
719 		if (!hook->remove_battery(battery->bat, hook))
720 			power_supply_changed(battery->bat);
721 	}
722 	list_del(&hook->list);
723 	if (lock)
724 		mutex_unlock(&hook_mutex);
725 	pr_info("extension unregistered: %s\n", hook->name);
726 }
727 
728 void battery_hook_unregister(struct acpi_battery_hook *hook)
729 {
730 	__battery_hook_unregister(hook, 1);
731 }
732 EXPORT_SYMBOL_GPL(battery_hook_unregister);
733 
734 void battery_hook_register(struct acpi_battery_hook *hook)
735 {
736 	struct acpi_battery *battery;
737 
738 	mutex_lock(&hook_mutex);
739 	INIT_LIST_HEAD(&hook->list);
740 	list_add(&hook->list, &battery_hook_list);
741 	/*
742 	 * Now that the driver is registered, we need
743 	 * to notify the hook that a battery is available
744 	 * for each battery, so that the driver may add
745 	 * its attributes.
746 	 */
747 	list_for_each_entry(battery, &acpi_battery_list, list) {
748 		if (hook->add_battery(battery->bat, hook)) {
749 			/*
750 			 * If a add-battery returns non-zero,
751 			 * the registration of the extension has failed,
752 			 * and we will not add it to the list of loaded
753 			 * hooks.
754 			 */
755 			pr_err("extension failed to load: %s", hook->name);
756 			__battery_hook_unregister(hook, 0);
757 			goto end;
758 		}
759 
760 		power_supply_changed(battery->bat);
761 	}
762 	pr_info("new extension: %s\n", hook->name);
763 end:
764 	mutex_unlock(&hook_mutex);
765 }
766 EXPORT_SYMBOL_GPL(battery_hook_register);
767 
768 static void devm_battery_hook_unregister(void *data)
769 {
770 	struct acpi_battery_hook *hook = data;
771 
772 	battery_hook_unregister(hook);
773 }
774 
775 int devm_battery_hook_register(struct device *dev, struct acpi_battery_hook *hook)
776 {
777 	battery_hook_register(hook);
778 
779 	return devm_add_action_or_reset(dev, devm_battery_hook_unregister, hook);
780 }
781 EXPORT_SYMBOL_GPL(devm_battery_hook_register);
782 
783 /*
784  * This function gets called right after the battery sysfs
785  * attributes have been added, so that the drivers that
786  * define custom sysfs attributes can add their own.
787  */
788 static void battery_hook_add_battery(struct acpi_battery *battery)
789 {
790 	struct acpi_battery_hook *hook_node, *tmp;
791 
792 	mutex_lock(&hook_mutex);
793 	INIT_LIST_HEAD(&battery->list);
794 	list_add(&battery->list, &acpi_battery_list);
795 	/*
796 	 * Since we added a new battery to the list, we need to
797 	 * iterate over the hooks and call add_battery for each
798 	 * hook that was registered. This usually happens
799 	 * when a battery gets hotplugged or initialized
800 	 * during the battery module initialization.
801 	 */
802 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
803 		if (hook_node->add_battery(battery->bat, hook_node)) {
804 			/*
805 			 * The notification of the extensions has failed, to
806 			 * prevent further errors we will unload the extension.
807 			 */
808 			pr_err("error in extension, unloading: %s",
809 					hook_node->name);
810 			__battery_hook_unregister(hook_node, 0);
811 		}
812 	}
813 	mutex_unlock(&hook_mutex);
814 }
815 
816 static void battery_hook_remove_battery(struct acpi_battery *battery)
817 {
818 	struct acpi_battery_hook *hook;
819 
820 	mutex_lock(&hook_mutex);
821 	/*
822 	 * Before removing the hook, we need to remove all
823 	 * custom attributes from the battery.
824 	 */
825 	list_for_each_entry(hook, &battery_hook_list, list) {
826 		hook->remove_battery(battery->bat, hook);
827 	}
828 	/* Then, just remove the battery from the list */
829 	list_del(&battery->list);
830 	mutex_unlock(&hook_mutex);
831 }
832 
833 static void __exit battery_hook_exit(void)
834 {
835 	struct acpi_battery_hook *hook;
836 	struct acpi_battery_hook *ptr;
837 	/*
838 	 * At this point, the acpi_bus_unregister_driver()
839 	 * has called remove for all batteries. We just
840 	 * need to remove the hooks.
841 	 */
842 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
843 		__battery_hook_unregister(hook, 1);
844 	}
845 	mutex_destroy(&hook_mutex);
846 }
847 
848 static int sysfs_add_battery(struct acpi_battery *battery)
849 {
850 	struct power_supply_config psy_cfg = {
851 		.drv_data = battery,
852 		.attr_grp = acpi_battery_groups,
853 	};
854 	bool full_cap_broken = false;
855 
856 	if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
857 	    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
858 		full_cap_broken = true;
859 
860 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
861 		if (full_cap_broken) {
862 			battery->bat_desc.properties =
863 			    charge_battery_full_cap_broken_props;
864 			battery->bat_desc.num_properties =
865 			    ARRAY_SIZE(charge_battery_full_cap_broken_props);
866 		} else {
867 			battery->bat_desc.properties = charge_battery_props;
868 			battery->bat_desc.num_properties =
869 			    ARRAY_SIZE(charge_battery_props);
870 		}
871 	} else {
872 		if (full_cap_broken) {
873 			battery->bat_desc.properties =
874 			    energy_battery_full_cap_broken_props;
875 			battery->bat_desc.num_properties =
876 			    ARRAY_SIZE(energy_battery_full_cap_broken_props);
877 		} else {
878 			battery->bat_desc.properties = energy_battery_props;
879 			battery->bat_desc.num_properties =
880 			    ARRAY_SIZE(energy_battery_props);
881 		}
882 	}
883 
884 	battery->bat_desc.name = acpi_device_bid(battery->device);
885 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
886 	battery->bat_desc.get_property = acpi_battery_get_property;
887 
888 	battery->bat = power_supply_register_no_ws(&battery->device->dev,
889 				&battery->bat_desc, &psy_cfg);
890 
891 	if (IS_ERR(battery->bat)) {
892 		int result = PTR_ERR(battery->bat);
893 
894 		battery->bat = NULL;
895 		return result;
896 	}
897 	battery_hook_add_battery(battery);
898 	return 0;
899 }
900 
901 static void sysfs_remove_battery(struct acpi_battery *battery)
902 {
903 	mutex_lock(&battery->sysfs_lock);
904 	if (!battery->bat) {
905 		mutex_unlock(&battery->sysfs_lock);
906 		return;
907 	}
908 	battery_hook_remove_battery(battery);
909 	power_supply_unregister(battery->bat);
910 	battery->bat = NULL;
911 	mutex_unlock(&battery->sysfs_lock);
912 }
913 
914 static void find_battery(const struct dmi_header *dm, void *private)
915 {
916 	struct acpi_battery *battery = (struct acpi_battery *)private;
917 	/* Note: the hardcoded offsets below have been extracted from
918 	 * the source code of dmidecode.
919 	 */
920 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
921 		const u8 *dmi_data = (const u8 *)(dm + 1);
922 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
923 
924 		if (dm->length >= 18)
925 			dmi_capacity *= dmi_data[17];
926 		if (battery->design_capacity * battery->design_voltage / 1000
927 		    != dmi_capacity &&
928 		    battery->design_capacity * 10 == dmi_capacity)
929 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
930 				&battery->flags);
931 	}
932 }
933 
934 /*
935  * According to the ACPI spec, some kinds of primary batteries can
936  * report percentage battery remaining capacity directly to OS.
937  * In this case, it reports the Last Full Charged Capacity == 100
938  * and BatteryPresentRate == 0xFFFFFFFF.
939  *
940  * Now we found some battery reports percentage remaining capacity
941  * even if it's rechargeable.
942  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
943  *
944  * Handle this correctly so that they won't break userspace.
945  */
946 static void acpi_battery_quirks(struct acpi_battery *battery)
947 {
948 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
949 		return;
950 
951 	if (battery->full_charge_capacity == 100 &&
952 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
953 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
954 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
955 		battery->full_charge_capacity = battery->design_capacity;
956 		battery->capacity_now = (battery->capacity_now *
957 				battery->full_charge_capacity) / 100;
958 	}
959 
960 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
961 		return;
962 
963 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
964 		const char *s;
965 
966 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
967 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
968 			dmi_walk(find_battery, battery);
969 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
970 				     &battery->flags) &&
971 			    battery->design_voltage) {
972 				battery->design_capacity =
973 				    battery->design_capacity *
974 				    10000 / battery->design_voltage;
975 				battery->full_charge_capacity =
976 				    battery->full_charge_capacity *
977 				    10000 / battery->design_voltage;
978 				battery->design_capacity_warning =
979 				    battery->design_capacity_warning *
980 				    10000 / battery->design_voltage;
981 				battery->capacity_now = battery->capacity_now *
982 				    10000 / battery->design_voltage;
983 			}
984 		}
985 	}
986 
987 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
988 		return;
989 
990 	if (acpi_battery_is_degraded(battery) &&
991 	    battery->capacity_now > battery->full_charge_capacity) {
992 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
993 		battery->capacity_now = battery->full_charge_capacity;
994 	}
995 }
996 
997 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
998 {
999 	int result = acpi_battery_get_status(battery);
1000 
1001 	if (result)
1002 		return result;
1003 
1004 	if (!acpi_battery_present(battery)) {
1005 		sysfs_remove_battery(battery);
1006 		battery->update_time = 0;
1007 		return 0;
1008 	}
1009 
1010 	if (resume)
1011 		return 0;
1012 
1013 	if (!battery->update_time) {
1014 		result = acpi_battery_get_info(battery);
1015 		if (result)
1016 			return result;
1017 		acpi_battery_init_alarm(battery);
1018 	}
1019 
1020 	result = acpi_battery_get_state(battery);
1021 	if (result)
1022 		return result;
1023 	acpi_battery_quirks(battery);
1024 
1025 	if (!battery->bat) {
1026 		result = sysfs_add_battery(battery);
1027 		if (result)
1028 			return result;
1029 	}
1030 
1031 	/*
1032 	 * Wakeup the system if battery is critical low
1033 	 * or lower than the alarm level
1034 	 */
1035 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1036 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1037 	     (battery->capacity_now <= battery->alarm)))
1038 		acpi_pm_wakeup_event(&battery->device->dev);
1039 
1040 	return result;
1041 }
1042 
1043 static void acpi_battery_refresh(struct acpi_battery *battery)
1044 {
1045 	int power_unit;
1046 
1047 	if (!battery->bat)
1048 		return;
1049 
1050 	power_unit = battery->power_unit;
1051 
1052 	acpi_battery_get_info(battery);
1053 
1054 	if (power_unit == battery->power_unit)
1055 		return;
1056 
1057 	/* The battery has changed its reporting units. */
1058 	sysfs_remove_battery(battery);
1059 	sysfs_add_battery(battery);
1060 }
1061 
1062 /* Driver Interface */
1063 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
1064 {
1065 	struct acpi_device *device = data;
1066 	struct acpi_battery *battery = acpi_driver_data(device);
1067 	struct power_supply *old;
1068 
1069 	if (!battery)
1070 		return;
1071 	old = battery->bat;
1072 	/*
1073 	 * On Acer Aspire V5-573G notifications are sometimes triggered too
1074 	 * early. For example, when AC is unplugged and notification is
1075 	 * triggered, battery state is still reported as "Full", and changes to
1076 	 * "Discharging" only after short delay, without any notification.
1077 	 */
1078 	if (battery_notification_delay_ms > 0)
1079 		msleep(battery_notification_delay_ms);
1080 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1081 		acpi_battery_refresh(battery);
1082 	acpi_battery_update(battery, false);
1083 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1084 					dev_name(&device->dev), event,
1085 					acpi_battery_present(battery));
1086 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1087 	/* acpi_battery_update could remove power_supply object */
1088 	if (old && battery->bat)
1089 		power_supply_changed(battery->bat);
1090 }
1091 
1092 static int battery_notify(struct notifier_block *nb,
1093 			       unsigned long mode, void *_unused)
1094 {
1095 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1096 						    pm_nb);
1097 	int result;
1098 
1099 	switch (mode) {
1100 	case PM_POST_HIBERNATION:
1101 	case PM_POST_SUSPEND:
1102 		if (!acpi_battery_present(battery))
1103 			return 0;
1104 
1105 		if (battery->bat) {
1106 			acpi_battery_refresh(battery);
1107 		} else {
1108 			result = acpi_battery_get_info(battery);
1109 			if (result)
1110 				return result;
1111 
1112 			result = sysfs_add_battery(battery);
1113 			if (result)
1114 				return result;
1115 		}
1116 
1117 		acpi_battery_init_alarm(battery);
1118 		acpi_battery_get_state(battery);
1119 		break;
1120 	}
1121 
1122 	return 0;
1123 }
1124 
1125 static int __init
1126 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1127 {
1128 	battery_bix_broken_package = 1;
1129 	return 0;
1130 }
1131 
1132 static int __init
1133 battery_notification_delay_quirk(const struct dmi_system_id *d)
1134 {
1135 	battery_notification_delay_ms = 1000;
1136 	return 0;
1137 }
1138 
1139 static int __init
1140 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1141 {
1142 	battery_ac_is_broken = 1;
1143 	return 0;
1144 }
1145 
1146 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1147 	{
1148 		/* NEC LZ750/LS */
1149 		.callback = battery_bix_broken_package_quirk,
1150 		.matches = {
1151 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1152 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1153 		},
1154 	},
1155 	{
1156 		/* Acer Aspire V5-573G */
1157 		.callback = battery_notification_delay_quirk,
1158 		.matches = {
1159 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1160 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1161 		},
1162 	},
1163 	{
1164 		/* Point of View mobii wintab p800w */
1165 		.callback = battery_ac_is_broken_quirk,
1166 		.matches = {
1167 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1168 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1169 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1170 			/* Above matches are too generic, add bios-date match */
1171 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1172 		},
1173 	},
1174 	{
1175 		/* Microsoft Surface Go 3 */
1176 		.callback = battery_notification_delay_quirk,
1177 		.matches = {
1178 			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
1179 			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
1180 		},
1181 	},
1182 	{},
1183 };
1184 
1185 /*
1186  * Some machines'(E,G Lenovo Z480) ECs are not stable
1187  * during boot up and this causes battery driver fails to be
1188  * probed due to failure of getting battery information
1189  * from EC sometimes. After several retries, the operation
1190  * may work. So add retry code here and 20ms sleep between
1191  * every retries.
1192  */
1193 static int acpi_battery_update_retry(struct acpi_battery *battery)
1194 {
1195 	int retry, ret;
1196 
1197 	for (retry = 5; retry; retry--) {
1198 		ret = acpi_battery_update(battery, false);
1199 		if (!ret)
1200 			break;
1201 
1202 		msleep(20);
1203 	}
1204 	return ret;
1205 }
1206 
1207 static int acpi_battery_add(struct acpi_device *device)
1208 {
1209 	int result = 0;
1210 	struct acpi_battery *battery = NULL;
1211 
1212 	if (!device)
1213 		return -EINVAL;
1214 
1215 	if (device->dep_unmet)
1216 		return -EPROBE_DEFER;
1217 
1218 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1219 	if (!battery)
1220 		return -ENOMEM;
1221 	battery->device = device;
1222 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1223 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1224 	device->driver_data = battery;
1225 	mutex_init(&battery->lock);
1226 	mutex_init(&battery->sysfs_lock);
1227 	if (acpi_has_method(battery->device->handle, "_BIX"))
1228 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1229 
1230 	result = acpi_battery_update_retry(battery);
1231 	if (result)
1232 		goto fail;
1233 
1234 	pr_info("Slot [%s] (battery %s)\n", acpi_device_bid(device),
1235 		device->status.battery_present ? "present" : "absent");
1236 
1237 	battery->pm_nb.notifier_call = battery_notify;
1238 	register_pm_notifier(&battery->pm_nb);
1239 
1240 	device_init_wakeup(&device->dev, 1);
1241 
1242 	result = acpi_dev_install_notify_handler(device, ACPI_ALL_NOTIFY,
1243 						 acpi_battery_notify, device);
1244 	if (result)
1245 		goto fail_pm;
1246 
1247 	return 0;
1248 
1249 fail_pm:
1250 	device_init_wakeup(&device->dev, 0);
1251 	unregister_pm_notifier(&battery->pm_nb);
1252 fail:
1253 	sysfs_remove_battery(battery);
1254 	mutex_destroy(&battery->lock);
1255 	mutex_destroy(&battery->sysfs_lock);
1256 	kfree(battery);
1257 
1258 	return result;
1259 }
1260 
1261 static void acpi_battery_remove(struct acpi_device *device)
1262 {
1263 	struct acpi_battery *battery = NULL;
1264 
1265 	if (!device || !acpi_driver_data(device))
1266 		return;
1267 
1268 	battery = acpi_driver_data(device);
1269 
1270 	acpi_dev_remove_notify_handler(device, ACPI_ALL_NOTIFY,
1271 				       acpi_battery_notify);
1272 
1273 	device_init_wakeup(&device->dev, 0);
1274 	unregister_pm_notifier(&battery->pm_nb);
1275 	sysfs_remove_battery(battery);
1276 
1277 	mutex_destroy(&battery->lock);
1278 	mutex_destroy(&battery->sysfs_lock);
1279 	kfree(battery);
1280 }
1281 
1282 #ifdef CONFIG_PM_SLEEP
1283 /* this is needed to learn about changes made in suspended state */
1284 static int acpi_battery_resume(struct device *dev)
1285 {
1286 	struct acpi_battery *battery;
1287 
1288 	if (!dev)
1289 		return -EINVAL;
1290 
1291 	battery = acpi_driver_data(to_acpi_device(dev));
1292 	if (!battery)
1293 		return -EINVAL;
1294 
1295 	battery->update_time = 0;
1296 	acpi_battery_update(battery, true);
1297 	return 0;
1298 }
1299 #else
1300 #define acpi_battery_resume NULL
1301 #endif
1302 
1303 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1304 
1305 static struct acpi_driver acpi_battery_driver = {
1306 	.name = "battery",
1307 	.class = ACPI_BATTERY_CLASS,
1308 	.ids = battery_device_ids,
1309 	.ops = {
1310 		.add = acpi_battery_add,
1311 		.remove = acpi_battery_remove,
1312 		},
1313 	.drv.pm = &acpi_battery_pm,
1314 };
1315 
1316 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1317 {
1318 	int result;
1319 
1320 	if (acpi_quirk_skip_acpi_ac_and_battery())
1321 		return;
1322 
1323 	dmi_check_system(bat_dmi_table);
1324 
1325 	result = acpi_bus_register_driver(&acpi_battery_driver);
1326 	battery_driver_registered = (result == 0);
1327 }
1328 
1329 static int __init acpi_battery_init(void)
1330 {
1331 	if (acpi_disabled)
1332 		return -ENODEV;
1333 
1334 	async_cookie = async_schedule(acpi_battery_init_async, NULL);
1335 	return 0;
1336 }
1337 
1338 static void __exit acpi_battery_exit(void)
1339 {
1340 	async_synchronize_cookie(async_cookie + 1);
1341 	if (battery_driver_registered) {
1342 		acpi_bus_unregister_driver(&acpi_battery_driver);
1343 		battery_hook_exit();
1344 	}
1345 }
1346 
1347 module_init(acpi_battery_init);
1348 module_exit(acpi_battery_exit);
1349