xref: /linux/drivers/acpi/battery.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
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) KBUILD_MODNAME ": " 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 #ifdef CONFIG_ACPI_PROCFS_POWER
28 #include <linux/proc_fs.h>
29 #include <linux/seq_file.h>
30 #include <linux/uaccess.h>
31 #endif
32 
33 #include <linux/acpi.h>
34 #include <linux/power_supply.h>
35 
36 #include <acpi/battery.h>
37 
38 #define PREFIX "ACPI: "
39 
40 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
41 #define ACPI_BATTERY_CAPACITY_VALID(capacity) \
42 	((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
43 
44 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
45 
46 /* Battery power unit: 0 means mW, 1 means mA */
47 #define ACPI_BATTERY_POWER_UNIT_MA	1
48 
49 #define ACPI_BATTERY_STATE_DISCHARGING	0x1
50 #define ACPI_BATTERY_STATE_CHARGING	0x2
51 #define ACPI_BATTERY_STATE_CRITICAL	0x4
52 
53 #define _COMPONENT		ACPI_BATTERY_COMPONENT
54 
55 ACPI_MODULE_NAME("battery");
56 
57 MODULE_AUTHOR("Paul Diefenbaugh");
58 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
59 MODULE_DESCRIPTION("ACPI Battery Driver");
60 MODULE_LICENSE("GPL");
61 
62 static async_cookie_t async_cookie;
63 static bool battery_driver_registered;
64 static int battery_bix_broken_package;
65 static int battery_notification_delay_ms;
66 static int battery_ac_is_broken;
67 static int battery_check_pmic = 1;
68 static unsigned int cache_time = 1000;
69 module_param(cache_time, uint, 0644);
70 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
71 
72 #ifdef CONFIG_ACPI_PROCFS_POWER
73 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
74 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
75 #endif
76 
77 static const struct acpi_device_id battery_device_ids[] = {
78 	{"PNP0C0A", 0},
79 	{"", 0},
80 };
81 
82 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
83 
84 /* Lists of PMIC ACPI HIDs with an (often better) native battery driver */
85 static const char * const acpi_battery_blacklist[] = {
86 	"INT33F4", /* X-Powers AXP288 PMIC */
87 };
88 
89 enum {
90 	ACPI_BATTERY_ALARM_PRESENT,
91 	ACPI_BATTERY_XINFO_PRESENT,
92 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
93 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
94 	   switches between mWh and mAh depending on whether the system
95 	   is running on battery or not.  When mAh is the unit, most
96 	   reported values are incorrect and need to be adjusted by
97 	   10000/design_voltage.  Verified on x201, t410, t410s, and x220.
98 	   Pre-2010 and 2012 models appear to always report in mWh and
99 	   are thus unaffected (tested with t42, t61, t500, x200, x300,
100 	   and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
101 	   the 2011 models that fixes the issue (tested on x220 with a
102 	   post-1.29 BIOS), but as of Nov. 2012, no such update is
103 	   available for the 2010 models.  */
104 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
105 	/* for batteries reporting current capacity with design capacity
106 	 * on a full charge, but showing degradation in full charge cap.
107 	 */
108 	ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
109 };
110 
111 struct acpi_battery {
112 	struct mutex lock;
113 	struct mutex sysfs_lock;
114 	struct power_supply *bat;
115 	struct power_supply_desc bat_desc;
116 	struct acpi_device *device;
117 	struct notifier_block pm_nb;
118 	struct list_head list;
119 	unsigned long update_time;
120 	int revision;
121 	int rate_now;
122 	int capacity_now;
123 	int voltage_now;
124 	int design_capacity;
125 	int full_charge_capacity;
126 	int technology;
127 	int design_voltage;
128 	int design_capacity_warning;
129 	int design_capacity_low;
130 	int cycle_count;
131 	int measurement_accuracy;
132 	int max_sampling_time;
133 	int min_sampling_time;
134 	int max_averaging_interval;
135 	int min_averaging_interval;
136 	int capacity_granularity_1;
137 	int capacity_granularity_2;
138 	int alarm;
139 	char model_number[32];
140 	char serial_number[32];
141 	char type[32];
142 	char oem_info[32];
143 	int state;
144 	int power_unit;
145 	unsigned long flags;
146 };
147 
148 #define to_acpi_battery(x) power_supply_get_drvdata(x)
149 
150 static inline int acpi_battery_present(struct acpi_battery *battery)
151 {
152 	return battery->device->status.battery_present;
153 }
154 
155 static int acpi_battery_technology(struct acpi_battery *battery)
156 {
157 	if (!strcasecmp("NiCd", battery->type))
158 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
159 	if (!strcasecmp("NiMH", battery->type))
160 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
161 	if (!strcasecmp("LION", battery->type))
162 		return POWER_SUPPLY_TECHNOLOGY_LION;
163 	if (!strncasecmp("LI-ION", battery->type, 6))
164 		return POWER_SUPPLY_TECHNOLOGY_LION;
165 	if (!strcasecmp("LiP", battery->type))
166 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
167 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
168 }
169 
170 static int acpi_battery_get_state(struct acpi_battery *battery);
171 
172 static int acpi_battery_is_charged(struct acpi_battery *battery)
173 {
174 	/* charging, discharging or critical low */
175 	if (battery->state != 0)
176 		return 0;
177 
178 	/* battery not reporting charge */
179 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
180 	    battery->capacity_now == 0)
181 		return 0;
182 
183 	/* good batteries update full_charge as the batteries degrade */
184 	if (battery->full_charge_capacity == battery->capacity_now)
185 		return 1;
186 
187 	/* fallback to using design values for broken batteries */
188 	if (battery->design_capacity == battery->capacity_now)
189 		return 1;
190 
191 	/* we don't do any sort of metric based on percentages */
192 	return 0;
193 }
194 
195 static bool acpi_battery_is_degraded(struct acpi_battery *battery)
196 {
197 	return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
198 		ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
199 		battery->full_charge_capacity < battery->design_capacity;
200 }
201 
202 static int acpi_battery_handle_discharging(struct acpi_battery *battery)
203 {
204 	/*
205 	 * Some devices wrongly report discharging if the battery's charge level
206 	 * was above the device's start charging threshold atm the AC adapter
207 	 * was plugged in and the device thus did not start a new charge cycle.
208 	 */
209 	if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
210 	    battery->rate_now == 0)
211 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
212 
213 	return POWER_SUPPLY_STATUS_DISCHARGING;
214 }
215 
216 static int acpi_battery_get_property(struct power_supply *psy,
217 				     enum power_supply_property psp,
218 				     union power_supply_propval *val)
219 {
220 	int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, ret = 0;
221 	struct acpi_battery *battery = to_acpi_battery(psy);
222 
223 	if (acpi_battery_present(battery)) {
224 		/* run battery update only if it is present */
225 		acpi_battery_get_state(battery);
226 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
227 		return -ENODEV;
228 	switch (psp) {
229 	case POWER_SUPPLY_PROP_STATUS:
230 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
231 			val->intval = acpi_battery_handle_discharging(battery);
232 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
233 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
234 		else if (acpi_battery_is_charged(battery))
235 			val->intval = POWER_SUPPLY_STATUS_FULL;
236 		else
237 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
238 		break;
239 	case POWER_SUPPLY_PROP_PRESENT:
240 		val->intval = acpi_battery_present(battery);
241 		break;
242 	case POWER_SUPPLY_PROP_TECHNOLOGY:
243 		val->intval = acpi_battery_technology(battery);
244 		break;
245 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
246 		val->intval = battery->cycle_count;
247 		break;
248 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
249 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
250 			ret = -ENODEV;
251 		else
252 			val->intval = battery->design_voltage * 1000;
253 		break;
254 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
255 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
256 			ret = -ENODEV;
257 		else
258 			val->intval = battery->voltage_now * 1000;
259 		break;
260 	case POWER_SUPPLY_PROP_CURRENT_NOW:
261 	case POWER_SUPPLY_PROP_POWER_NOW:
262 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
263 			ret = -ENODEV;
264 		else
265 			val->intval = battery->rate_now * 1000;
266 		break;
267 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
268 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
269 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
270 			ret = -ENODEV;
271 		else
272 			val->intval = battery->design_capacity * 1000;
273 		break;
274 	case POWER_SUPPLY_PROP_CHARGE_FULL:
275 	case POWER_SUPPLY_PROP_ENERGY_FULL:
276 		if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
277 			ret = -ENODEV;
278 		else
279 			val->intval = battery->full_charge_capacity * 1000;
280 		break;
281 	case POWER_SUPPLY_PROP_CHARGE_NOW:
282 	case POWER_SUPPLY_PROP_ENERGY_NOW:
283 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
284 			ret = -ENODEV;
285 		else
286 			val->intval = battery->capacity_now * 1000;
287 		break;
288 	case POWER_SUPPLY_PROP_CAPACITY:
289 		if (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
290 			full_capacity = battery->full_charge_capacity;
291 		else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
292 			full_capacity = battery->design_capacity;
293 
294 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
295 		    full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
296 			ret = -ENODEV;
297 		else
298 			val->intval = battery->capacity_now * 100/
299 					full_capacity;
300 		break;
301 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
302 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
303 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
304 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
305 			(battery->capacity_now <= battery->alarm))
306 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
307 		else if (acpi_battery_is_charged(battery))
308 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
309 		else
310 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
311 		break;
312 	case POWER_SUPPLY_PROP_MODEL_NAME:
313 		val->strval = battery->model_number;
314 		break;
315 	case POWER_SUPPLY_PROP_MANUFACTURER:
316 		val->strval = battery->oem_info;
317 		break;
318 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
319 		val->strval = battery->serial_number;
320 		break;
321 	default:
322 		ret = -EINVAL;
323 	}
324 	return ret;
325 }
326 
327 static enum power_supply_property charge_battery_props[] = {
328 	POWER_SUPPLY_PROP_STATUS,
329 	POWER_SUPPLY_PROP_PRESENT,
330 	POWER_SUPPLY_PROP_TECHNOLOGY,
331 	POWER_SUPPLY_PROP_CYCLE_COUNT,
332 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
333 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
334 	POWER_SUPPLY_PROP_CURRENT_NOW,
335 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
336 	POWER_SUPPLY_PROP_CHARGE_FULL,
337 	POWER_SUPPLY_PROP_CHARGE_NOW,
338 	POWER_SUPPLY_PROP_CAPACITY,
339 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
340 	POWER_SUPPLY_PROP_MODEL_NAME,
341 	POWER_SUPPLY_PROP_MANUFACTURER,
342 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
343 };
344 
345 static enum power_supply_property charge_battery_full_cap_broken_props[] = {
346 	POWER_SUPPLY_PROP_STATUS,
347 	POWER_SUPPLY_PROP_PRESENT,
348 	POWER_SUPPLY_PROP_TECHNOLOGY,
349 	POWER_SUPPLY_PROP_CYCLE_COUNT,
350 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
351 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
352 	POWER_SUPPLY_PROP_CURRENT_NOW,
353 	POWER_SUPPLY_PROP_CHARGE_NOW,
354 	POWER_SUPPLY_PROP_MODEL_NAME,
355 	POWER_SUPPLY_PROP_MANUFACTURER,
356 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
357 };
358 
359 static enum power_supply_property energy_battery_props[] = {
360 	POWER_SUPPLY_PROP_STATUS,
361 	POWER_SUPPLY_PROP_PRESENT,
362 	POWER_SUPPLY_PROP_TECHNOLOGY,
363 	POWER_SUPPLY_PROP_CYCLE_COUNT,
364 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
365 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
366 	POWER_SUPPLY_PROP_POWER_NOW,
367 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
368 	POWER_SUPPLY_PROP_ENERGY_FULL,
369 	POWER_SUPPLY_PROP_ENERGY_NOW,
370 	POWER_SUPPLY_PROP_CAPACITY,
371 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
372 	POWER_SUPPLY_PROP_MODEL_NAME,
373 	POWER_SUPPLY_PROP_MANUFACTURER,
374 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
375 };
376 
377 static enum power_supply_property energy_battery_full_cap_broken_props[] = {
378 	POWER_SUPPLY_PROP_STATUS,
379 	POWER_SUPPLY_PROP_PRESENT,
380 	POWER_SUPPLY_PROP_TECHNOLOGY,
381 	POWER_SUPPLY_PROP_CYCLE_COUNT,
382 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
383 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
384 	POWER_SUPPLY_PROP_POWER_NOW,
385 	POWER_SUPPLY_PROP_ENERGY_NOW,
386 	POWER_SUPPLY_PROP_MODEL_NAME,
387 	POWER_SUPPLY_PROP_MANUFACTURER,
388 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
389 };
390 
391 /* --------------------------------------------------------------------------
392                                Battery Management
393    -------------------------------------------------------------------------- */
394 struct acpi_offsets {
395 	size_t offset;		/* offset inside struct acpi_sbs_battery */
396 	u8 mode;		/* int or string? */
397 };
398 
399 static const struct acpi_offsets state_offsets[] = {
400 	{offsetof(struct acpi_battery, state), 0},
401 	{offsetof(struct acpi_battery, rate_now), 0},
402 	{offsetof(struct acpi_battery, capacity_now), 0},
403 	{offsetof(struct acpi_battery, voltage_now), 0},
404 };
405 
406 static const struct acpi_offsets info_offsets[] = {
407 	{offsetof(struct acpi_battery, power_unit), 0},
408 	{offsetof(struct acpi_battery, design_capacity), 0},
409 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
410 	{offsetof(struct acpi_battery, technology), 0},
411 	{offsetof(struct acpi_battery, design_voltage), 0},
412 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
413 	{offsetof(struct acpi_battery, design_capacity_low), 0},
414 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
415 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
416 	{offsetof(struct acpi_battery, model_number), 1},
417 	{offsetof(struct acpi_battery, serial_number), 1},
418 	{offsetof(struct acpi_battery, type), 1},
419 	{offsetof(struct acpi_battery, oem_info), 1},
420 };
421 
422 static const struct acpi_offsets extended_info_offsets[] = {
423 	{offsetof(struct acpi_battery, revision), 0},
424 	{offsetof(struct acpi_battery, power_unit), 0},
425 	{offsetof(struct acpi_battery, design_capacity), 0},
426 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
427 	{offsetof(struct acpi_battery, technology), 0},
428 	{offsetof(struct acpi_battery, design_voltage), 0},
429 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
430 	{offsetof(struct acpi_battery, design_capacity_low), 0},
431 	{offsetof(struct acpi_battery, cycle_count), 0},
432 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
433 	{offsetof(struct acpi_battery, max_sampling_time), 0},
434 	{offsetof(struct acpi_battery, min_sampling_time), 0},
435 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
436 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
437 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
438 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
439 	{offsetof(struct acpi_battery, model_number), 1},
440 	{offsetof(struct acpi_battery, serial_number), 1},
441 	{offsetof(struct acpi_battery, type), 1},
442 	{offsetof(struct acpi_battery, oem_info), 1},
443 };
444 
445 static int extract_package(struct acpi_battery *battery,
446 			   union acpi_object *package,
447 			   const struct acpi_offsets *offsets, int num)
448 {
449 	int i;
450 	union acpi_object *element;
451 	if (package->type != ACPI_TYPE_PACKAGE)
452 		return -EFAULT;
453 	for (i = 0; i < num; ++i) {
454 		if (package->package.count <= i)
455 			return -EFAULT;
456 		element = &package->package.elements[i];
457 		if (offsets[i].mode) {
458 			u8 *ptr = (u8 *)battery + offsets[i].offset;
459 			if (element->type == ACPI_TYPE_STRING ||
460 			    element->type == ACPI_TYPE_BUFFER)
461 				strncpy(ptr, element->string.pointer, 32);
462 			else if (element->type == ACPI_TYPE_INTEGER) {
463 				strncpy(ptr, (u8 *)&element->integer.value,
464 					sizeof(u64));
465 				ptr[sizeof(u64)] = 0;
466 			} else
467 				*ptr = 0; /* don't have value */
468 		} else {
469 			int *x = (int *)((u8 *)battery + offsets[i].offset);
470 			*x = (element->type == ACPI_TYPE_INTEGER) ?
471 				element->integer.value : -1;
472 		}
473 	}
474 	return 0;
475 }
476 
477 static int acpi_battery_get_status(struct acpi_battery *battery)
478 {
479 	if (acpi_bus_get_status(battery->device)) {
480 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
481 		return -ENODEV;
482 	}
483 	return 0;
484 }
485 
486 
487 static int extract_battery_info(const int use_bix,
488 			 struct acpi_battery *battery,
489 			 const struct acpi_buffer *buffer)
490 {
491 	int result = -EFAULT;
492 
493 	if (use_bix && battery_bix_broken_package)
494 		result = extract_package(battery, buffer->pointer,
495 				extended_info_offsets + 1,
496 				ARRAY_SIZE(extended_info_offsets) - 1);
497 	else if (use_bix)
498 		result = extract_package(battery, buffer->pointer,
499 				extended_info_offsets,
500 				ARRAY_SIZE(extended_info_offsets));
501 	else
502 		result = extract_package(battery, buffer->pointer,
503 				info_offsets, ARRAY_SIZE(info_offsets));
504 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
505 		battery->full_charge_capacity = battery->design_capacity;
506 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
507 	    battery->power_unit && battery->design_voltage) {
508 		battery->design_capacity = battery->design_capacity *
509 		    10000 / battery->design_voltage;
510 		battery->full_charge_capacity = battery->full_charge_capacity *
511 		    10000 / battery->design_voltage;
512 		battery->design_capacity_warning =
513 		    battery->design_capacity_warning *
514 		    10000 / battery->design_voltage;
515 		/* Curiously, design_capacity_low, unlike the rest of them,
516 		   is correct.  */
517 		/* capacity_granularity_* equal 1 on the systems tested, so
518 		   it's impossible to tell if they would need an adjustment
519 		   or not if their values were higher.  */
520 	}
521 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
522 	    battery->capacity_now > battery->full_charge_capacity)
523 		battery->capacity_now = battery->full_charge_capacity;
524 
525 	return result;
526 }
527 
528 static int acpi_battery_get_info(struct acpi_battery *battery)
529 {
530 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
531 	int use_bix;
532 	int result = -ENODEV;
533 
534 	if (!acpi_battery_present(battery))
535 		return 0;
536 
537 
538 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
539 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
540 		acpi_status status = AE_ERROR;
541 
542 		mutex_lock(&battery->lock);
543 		status = acpi_evaluate_object(battery->device->handle,
544 					      use_bix ? "_BIX":"_BIF",
545 					      NULL, &buffer);
546 		mutex_unlock(&battery->lock);
547 
548 		if (ACPI_FAILURE(status)) {
549 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating %s",
550 					use_bix ? "_BIX":"_BIF"));
551 		} else {
552 			result = extract_battery_info(use_bix,
553 						      battery,
554 						      &buffer);
555 
556 			kfree(buffer.pointer);
557 			break;
558 		}
559 	}
560 
561 	if (!result && !use_bix && xinfo)
562 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
563 
564 	return result;
565 }
566 
567 static int acpi_battery_get_state(struct acpi_battery *battery)
568 {
569 	int result = 0;
570 	acpi_status status = 0;
571 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
572 
573 	if (!acpi_battery_present(battery))
574 		return 0;
575 
576 	if (battery->update_time &&
577 	    time_before(jiffies, battery->update_time +
578 			msecs_to_jiffies(cache_time)))
579 		return 0;
580 
581 	mutex_lock(&battery->lock);
582 	status = acpi_evaluate_object(battery->device->handle, "_BST",
583 				      NULL, &buffer);
584 	mutex_unlock(&battery->lock);
585 
586 	if (ACPI_FAILURE(status)) {
587 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
588 		return -ENODEV;
589 	}
590 
591 	result = extract_package(battery, buffer.pointer,
592 				 state_offsets, ARRAY_SIZE(state_offsets));
593 	battery->update_time = jiffies;
594 	kfree(buffer.pointer);
595 
596 	/* For buggy DSDTs that report negative 16-bit values for either
597 	 * charging or discharging current and/or report 0 as 65536
598 	 * due to bad math.
599 	 */
600 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
601 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
602 		(s16)(battery->rate_now) < 0) {
603 		battery->rate_now = abs((s16)battery->rate_now);
604 		pr_warn_once(FW_BUG "battery: (dis)charge rate invalid.\n");
605 	}
606 
607 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
608 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
609 		battery->capacity_now = (battery->capacity_now *
610 				battery->full_charge_capacity) / 100;
611 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
612 	    battery->power_unit && battery->design_voltage) {
613 		battery->capacity_now = battery->capacity_now *
614 		    10000 / battery->design_voltage;
615 	}
616 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
617 	    battery->capacity_now > battery->full_charge_capacity)
618 		battery->capacity_now = battery->full_charge_capacity;
619 
620 	return result;
621 }
622 
623 static int acpi_battery_set_alarm(struct acpi_battery *battery)
624 {
625 	acpi_status status = 0;
626 
627 	if (!acpi_battery_present(battery) ||
628 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
629 		return -ENODEV;
630 
631 	mutex_lock(&battery->lock);
632 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
633 					    battery->alarm);
634 	mutex_unlock(&battery->lock);
635 
636 	if (ACPI_FAILURE(status))
637 		return -ENODEV;
638 
639 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
640 	return 0;
641 }
642 
643 static int acpi_battery_init_alarm(struct acpi_battery *battery)
644 {
645 	/* See if alarms are supported, and if so, set default */
646 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
647 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
648 		return 0;
649 	}
650 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
651 	if (!battery->alarm)
652 		battery->alarm = battery->design_capacity_warning;
653 	return acpi_battery_set_alarm(battery);
654 }
655 
656 static ssize_t acpi_battery_alarm_show(struct device *dev,
657 					struct device_attribute *attr,
658 					char *buf)
659 {
660 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
661 	return sprintf(buf, "%d\n", battery->alarm * 1000);
662 }
663 
664 static ssize_t acpi_battery_alarm_store(struct device *dev,
665 					struct device_attribute *attr,
666 					const char *buf, size_t count)
667 {
668 	unsigned long x;
669 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
670 	if (sscanf(buf, "%lu\n", &x) == 1)
671 		battery->alarm = x/1000;
672 	if (acpi_battery_present(battery))
673 		acpi_battery_set_alarm(battery);
674 	return count;
675 }
676 
677 static const struct device_attribute alarm_attr = {
678 	.attr = {.name = "alarm", .mode = 0644},
679 	.show = acpi_battery_alarm_show,
680 	.store = acpi_battery_alarm_store,
681 };
682 
683 /*
684  * The Battery Hooking API
685  *
686  * This API is used inside other drivers that need to expose
687  * platform-specific behaviour within the generic driver in a
688  * generic way.
689  *
690  */
691 
692 static LIST_HEAD(acpi_battery_list);
693 static LIST_HEAD(battery_hook_list);
694 static DEFINE_MUTEX(hook_mutex);
695 
696 static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
697 {
698 	struct acpi_battery *battery;
699 	/*
700 	 * In order to remove a hook, we first need to
701 	 * de-register all the batteries that are registered.
702 	 */
703 	if (lock)
704 		mutex_lock(&hook_mutex);
705 	list_for_each_entry(battery, &acpi_battery_list, list) {
706 		hook->remove_battery(battery->bat);
707 	}
708 	list_del(&hook->list);
709 	if (lock)
710 		mutex_unlock(&hook_mutex);
711 	pr_info("extension unregistered: %s\n", hook->name);
712 }
713 
714 void battery_hook_unregister(struct acpi_battery_hook *hook)
715 {
716 	__battery_hook_unregister(hook, 1);
717 }
718 EXPORT_SYMBOL_GPL(battery_hook_unregister);
719 
720 void battery_hook_register(struct acpi_battery_hook *hook)
721 {
722 	struct acpi_battery *battery;
723 
724 	mutex_lock(&hook_mutex);
725 	INIT_LIST_HEAD(&hook->list);
726 	list_add(&hook->list, &battery_hook_list);
727 	/*
728 	 * Now that the driver is registered, we need
729 	 * to notify the hook that a battery is available
730 	 * for each battery, so that the driver may add
731 	 * its attributes.
732 	 */
733 	list_for_each_entry(battery, &acpi_battery_list, list) {
734 		if (hook->add_battery(battery->bat)) {
735 			/*
736 			 * If a add-battery returns non-zero,
737 			 * the registration of the extension has failed,
738 			 * and we will not add it to the list of loaded
739 			 * hooks.
740 			 */
741 			pr_err("extension failed to load: %s", hook->name);
742 			__battery_hook_unregister(hook, 0);
743 			goto end;
744 		}
745 	}
746 	pr_info("new extension: %s\n", hook->name);
747 end:
748 	mutex_unlock(&hook_mutex);
749 }
750 EXPORT_SYMBOL_GPL(battery_hook_register);
751 
752 /*
753  * This function gets called right after the battery sysfs
754  * attributes have been added, so that the drivers that
755  * define custom sysfs attributes can add their own.
756 */
757 static void battery_hook_add_battery(struct acpi_battery *battery)
758 {
759 	struct acpi_battery_hook *hook_node, *tmp;
760 
761 	mutex_lock(&hook_mutex);
762 	INIT_LIST_HEAD(&battery->list);
763 	list_add(&battery->list, &acpi_battery_list);
764 	/*
765 	 * Since we added a new battery to the list, we need to
766 	 * iterate over the hooks and call add_battery for each
767 	 * hook that was registered. This usually happens
768 	 * when a battery gets hotplugged or initialized
769 	 * during the battery module initialization.
770 	 */
771 	list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
772 		if (hook_node->add_battery(battery->bat)) {
773 			/*
774 			 * The notification of the extensions has failed, to
775 			 * prevent further errors we will unload the extension.
776 			 */
777 			pr_err("error in extension, unloading: %s",
778 					hook_node->name);
779 			__battery_hook_unregister(hook_node, 0);
780 		}
781 	}
782 	mutex_unlock(&hook_mutex);
783 }
784 
785 static void battery_hook_remove_battery(struct acpi_battery *battery)
786 {
787 	struct acpi_battery_hook *hook;
788 
789 	mutex_lock(&hook_mutex);
790 	/*
791 	 * Before removing the hook, we need to remove all
792 	 * custom attributes from the battery.
793 	 */
794 	list_for_each_entry(hook, &battery_hook_list, list) {
795 		hook->remove_battery(battery->bat);
796 	}
797 	/* Then, just remove the battery from the list */
798 	list_del(&battery->list);
799 	mutex_unlock(&hook_mutex);
800 }
801 
802 static void __exit battery_hook_exit(void)
803 {
804 	struct acpi_battery_hook *hook;
805 	struct acpi_battery_hook *ptr;
806 	/*
807 	 * At this point, the acpi_bus_unregister_driver()
808 	 * has called remove for all batteries. We just
809 	 * need to remove the hooks.
810 	 */
811 	list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
812 		__battery_hook_unregister(hook, 1);
813 	}
814 	mutex_destroy(&hook_mutex);
815 }
816 
817 static int sysfs_add_battery(struct acpi_battery *battery)
818 {
819 	struct power_supply_config psy_cfg = { .drv_data = battery, };
820 	bool full_cap_broken = false;
821 
822 	if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
823 	    !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
824 		full_cap_broken = true;
825 
826 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
827 		if (full_cap_broken) {
828 			battery->bat_desc.properties =
829 			    charge_battery_full_cap_broken_props;
830 			battery->bat_desc.num_properties =
831 			    ARRAY_SIZE(charge_battery_full_cap_broken_props);
832 		} else {
833 			battery->bat_desc.properties = charge_battery_props;
834 			battery->bat_desc.num_properties =
835 			    ARRAY_SIZE(charge_battery_props);
836 		}
837 	} else {
838 		if (full_cap_broken) {
839 			battery->bat_desc.properties =
840 			    energy_battery_full_cap_broken_props;
841 			battery->bat_desc.num_properties =
842 			    ARRAY_SIZE(energy_battery_full_cap_broken_props);
843 		} else {
844 			battery->bat_desc.properties = energy_battery_props;
845 			battery->bat_desc.num_properties =
846 			    ARRAY_SIZE(energy_battery_props);
847 		}
848 	}
849 
850 	battery->bat_desc.name = acpi_device_bid(battery->device);
851 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
852 	battery->bat_desc.get_property = acpi_battery_get_property;
853 
854 	battery->bat = power_supply_register_no_ws(&battery->device->dev,
855 				&battery->bat_desc, &psy_cfg);
856 
857 	if (IS_ERR(battery->bat)) {
858 		int result = PTR_ERR(battery->bat);
859 
860 		battery->bat = NULL;
861 		return result;
862 	}
863 	battery_hook_add_battery(battery);
864 	return device_create_file(&battery->bat->dev, &alarm_attr);
865 }
866 
867 static void sysfs_remove_battery(struct acpi_battery *battery)
868 {
869 	mutex_lock(&battery->sysfs_lock);
870 	if (!battery->bat) {
871 		mutex_unlock(&battery->sysfs_lock);
872 		return;
873 	}
874 	battery_hook_remove_battery(battery);
875 	device_remove_file(&battery->bat->dev, &alarm_attr);
876 	power_supply_unregister(battery->bat);
877 	battery->bat = NULL;
878 	mutex_unlock(&battery->sysfs_lock);
879 }
880 
881 static void find_battery(const struct dmi_header *dm, void *private)
882 {
883 	struct acpi_battery *battery = (struct acpi_battery *)private;
884 	/* Note: the hardcoded offsets below have been extracted from
885 	   the source code of dmidecode.  */
886 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
887 		const u8 *dmi_data = (const u8 *)(dm + 1);
888 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
889 		if (dm->length >= 18)
890 			dmi_capacity *= dmi_data[17];
891 		if (battery->design_capacity * battery->design_voltage / 1000
892 		    != dmi_capacity &&
893 		    battery->design_capacity * 10 == dmi_capacity)
894 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
895 				&battery->flags);
896 	}
897 }
898 
899 /*
900  * According to the ACPI spec, some kinds of primary batteries can
901  * report percentage battery remaining capacity directly to OS.
902  * In this case, it reports the Last Full Charged Capacity == 100
903  * and BatteryPresentRate == 0xFFFFFFFF.
904  *
905  * Now we found some battery reports percentage remaining capacity
906  * even if it's rechargeable.
907  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
908  *
909  * Handle this correctly so that they won't break userspace.
910  */
911 static void acpi_battery_quirks(struct acpi_battery *battery)
912 {
913 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
914 		return;
915 
916 	if (battery->full_charge_capacity == 100 &&
917 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
918 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
919 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
920 		battery->full_charge_capacity = battery->design_capacity;
921 		battery->capacity_now = (battery->capacity_now *
922 				battery->full_charge_capacity) / 100;
923 	}
924 
925 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
926 		return;
927 
928 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
929 		const char *s;
930 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
931 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
932 			dmi_walk(find_battery, battery);
933 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
934 				     &battery->flags) &&
935 			    battery->design_voltage) {
936 				battery->design_capacity =
937 				    battery->design_capacity *
938 				    10000 / battery->design_voltage;
939 				battery->full_charge_capacity =
940 				    battery->full_charge_capacity *
941 				    10000 / battery->design_voltage;
942 				battery->design_capacity_warning =
943 				    battery->design_capacity_warning *
944 				    10000 / battery->design_voltage;
945 				battery->capacity_now = battery->capacity_now *
946 				    10000 / battery->design_voltage;
947 			}
948 		}
949 	}
950 
951 	if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
952 		return;
953 
954 	if (acpi_battery_is_degraded(battery) &&
955 	    battery->capacity_now > battery->full_charge_capacity) {
956 		set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
957 		battery->capacity_now = battery->full_charge_capacity;
958 	}
959 }
960 
961 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
962 {
963 	int result = acpi_battery_get_status(battery);
964 
965 	if (result)
966 		return result;
967 
968 	if (!acpi_battery_present(battery)) {
969 		sysfs_remove_battery(battery);
970 		battery->update_time = 0;
971 		return 0;
972 	}
973 
974 	if (resume)
975 		return 0;
976 
977 	if (!battery->update_time) {
978 		result = acpi_battery_get_info(battery);
979 		if (result)
980 			return result;
981 		acpi_battery_init_alarm(battery);
982 	}
983 
984 	result = acpi_battery_get_state(battery);
985 	if (result)
986 		return result;
987 	acpi_battery_quirks(battery);
988 
989 	if (!battery->bat) {
990 		result = sysfs_add_battery(battery);
991 		if (result)
992 			return result;
993 	}
994 
995 	/*
996 	 * Wakeup the system if battery is critical low
997 	 * or lower than the alarm level
998 	 */
999 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
1000 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
1001             (battery->capacity_now <= battery->alarm)))
1002 		acpi_pm_wakeup_event(&battery->device->dev);
1003 
1004 	return result;
1005 }
1006 
1007 static void acpi_battery_refresh(struct acpi_battery *battery)
1008 {
1009 	int power_unit;
1010 
1011 	if (!battery->bat)
1012 		return;
1013 
1014 	power_unit = battery->power_unit;
1015 
1016 	acpi_battery_get_info(battery);
1017 
1018 	if (power_unit == battery->power_unit)
1019 		return;
1020 
1021 	/* The battery has changed its reporting units. */
1022 	sysfs_remove_battery(battery);
1023 	sysfs_add_battery(battery);
1024 }
1025 
1026 /* --------------------------------------------------------------------------
1027                               FS Interface (/proc)
1028    -------------------------------------------------------------------------- */
1029 
1030 #ifdef CONFIG_ACPI_PROCFS_POWER
1031 static struct proc_dir_entry *acpi_battery_dir;
1032 
1033 static const char *acpi_battery_units(const struct acpi_battery *battery)
1034 {
1035 	return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
1036 		"mA" : "mW";
1037 }
1038 
1039 static int acpi_battery_info_proc_show(struct seq_file *seq, void *offset)
1040 {
1041 	struct acpi_battery *battery = seq->private;
1042 	int result = acpi_battery_update(battery, false);
1043 
1044 	if (result)
1045 		goto end;
1046 
1047 	seq_printf(seq, "present:                 %s\n",
1048 		   acpi_battery_present(battery) ? "yes" : "no");
1049 	if (!acpi_battery_present(battery))
1050 		goto end;
1051 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
1052 		seq_printf(seq, "design capacity:         unknown\n");
1053 	else
1054 		seq_printf(seq, "design capacity:         %d %sh\n",
1055 			   battery->design_capacity,
1056 			   acpi_battery_units(battery));
1057 
1058 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
1059 		seq_printf(seq, "last full capacity:      unknown\n");
1060 	else
1061 		seq_printf(seq, "last full capacity:      %d %sh\n",
1062 			   battery->full_charge_capacity,
1063 			   acpi_battery_units(battery));
1064 
1065 	seq_printf(seq, "battery technology:      %srechargeable\n",
1066 		   battery->technology ? "" : "non-");
1067 
1068 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
1069 		seq_printf(seq, "design voltage:          unknown\n");
1070 	else
1071 		seq_printf(seq, "design voltage:          %d mV\n",
1072 			   battery->design_voltage);
1073 	seq_printf(seq, "design capacity warning: %d %sh\n",
1074 		   battery->design_capacity_warning,
1075 		   acpi_battery_units(battery));
1076 	seq_printf(seq, "design capacity low:     %d %sh\n",
1077 		   battery->design_capacity_low,
1078 		   acpi_battery_units(battery));
1079 	seq_printf(seq, "cycle count:		  %i\n", battery->cycle_count);
1080 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
1081 		   battery->capacity_granularity_1,
1082 		   acpi_battery_units(battery));
1083 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
1084 		   battery->capacity_granularity_2,
1085 		   acpi_battery_units(battery));
1086 	seq_printf(seq, "model number:            %s\n", battery->model_number);
1087 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
1088 	seq_printf(seq, "battery type:            %s\n", battery->type);
1089 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
1090       end:
1091 	if (result)
1092 		seq_printf(seq, "ERROR: Unable to read battery info\n");
1093 	return result;
1094 }
1095 
1096 static int acpi_battery_state_proc_show(struct seq_file *seq, void *offset)
1097 {
1098 	struct acpi_battery *battery = seq->private;
1099 	int result = acpi_battery_update(battery, false);
1100 
1101 	if (result)
1102 		goto end;
1103 
1104 	seq_printf(seq, "present:                 %s\n",
1105 		   acpi_battery_present(battery) ? "yes" : "no");
1106 	if (!acpi_battery_present(battery))
1107 		goto end;
1108 
1109 	seq_printf(seq, "capacity state:          %s\n",
1110 			(battery->state & 0x04) ? "critical" : "ok");
1111 	if ((battery->state & 0x01) && (battery->state & 0x02))
1112 		seq_printf(seq,
1113 			   "charging state:          charging/discharging\n");
1114 	else if (battery->state & 0x01)
1115 		seq_printf(seq, "charging state:          discharging\n");
1116 	else if (battery->state & 0x02)
1117 		seq_printf(seq, "charging state:          charging\n");
1118 	else
1119 		seq_printf(seq, "charging state:          charged\n");
1120 
1121 	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
1122 		seq_printf(seq, "present rate:            unknown\n");
1123 	else
1124 		seq_printf(seq, "present rate:            %d %s\n",
1125 			   battery->rate_now, acpi_battery_units(battery));
1126 
1127 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
1128 		seq_printf(seq, "remaining capacity:      unknown\n");
1129 	else
1130 		seq_printf(seq, "remaining capacity:      %d %sh\n",
1131 			   battery->capacity_now, acpi_battery_units(battery));
1132 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
1133 		seq_printf(seq, "present voltage:         unknown\n");
1134 	else
1135 		seq_printf(seq, "present voltage:         %d mV\n",
1136 			   battery->voltage_now);
1137       end:
1138 	if (result)
1139 		seq_printf(seq, "ERROR: Unable to read battery state\n");
1140 
1141 	return result;
1142 }
1143 
1144 static int acpi_battery_alarm_proc_show(struct seq_file *seq, void *offset)
1145 {
1146 	struct acpi_battery *battery = seq->private;
1147 	int result = acpi_battery_update(battery, false);
1148 
1149 	if (result)
1150 		goto end;
1151 
1152 	if (!acpi_battery_present(battery)) {
1153 		seq_printf(seq, "present:                 no\n");
1154 		goto end;
1155 	}
1156 	seq_printf(seq, "alarm:                   ");
1157 	if (battery->alarm) {
1158 		seq_printf(seq, "%u %sh\n", battery->alarm,
1159 				acpi_battery_units(battery));
1160 	} else {
1161 		seq_printf(seq, "unsupported\n");
1162 	}
1163       end:
1164 	if (result)
1165 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
1166 	return result;
1167 }
1168 
1169 static ssize_t acpi_battery_write_alarm(struct file *file,
1170 					const char __user * buffer,
1171 					size_t count, loff_t * ppos)
1172 {
1173 	int result = 0;
1174 	char alarm_string[12] = { '\0' };
1175 	struct seq_file *m = file->private_data;
1176 	struct acpi_battery *battery = m->private;
1177 
1178 	if (!battery || (count > sizeof(alarm_string) - 1))
1179 		return -EINVAL;
1180 	if (!acpi_battery_present(battery)) {
1181 		result = -ENODEV;
1182 		goto end;
1183 	}
1184 	if (copy_from_user(alarm_string, buffer, count)) {
1185 		result = -EFAULT;
1186 		goto end;
1187 	}
1188 	alarm_string[count] = '\0';
1189 	if (kstrtoint(alarm_string, 0, &battery->alarm)) {
1190 		result = -EINVAL;
1191 		goto end;
1192 	}
1193 	result = acpi_battery_set_alarm(battery);
1194       end:
1195 	if (result)
1196 		return result;
1197 	return count;
1198 }
1199 
1200 static int acpi_battery_alarm_proc_open(struct inode *inode, struct file *file)
1201 {
1202 	return single_open(file, acpi_battery_alarm_proc_show, PDE_DATA(inode));
1203 }
1204 
1205 static const struct proc_ops acpi_battery_alarm_proc_ops = {
1206 	.proc_open	= acpi_battery_alarm_proc_open,
1207 	.proc_read	= seq_read,
1208 	.proc_write	= acpi_battery_write_alarm,
1209 	.proc_lseek	= seq_lseek,
1210 	.proc_release	= single_release,
1211 };
1212 
1213 static int acpi_battery_add_fs(struct acpi_device *device)
1214 {
1215 	pr_warn(PREFIX "Deprecated procfs I/F for battery is loaded, please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
1216 	if (!acpi_device_dir(device)) {
1217 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
1218 						     acpi_battery_dir);
1219 		if (!acpi_device_dir(device))
1220 			return -ENODEV;
1221 	}
1222 
1223 	if (!proc_create_single_data("info", S_IRUGO, acpi_device_dir(device),
1224 			acpi_battery_info_proc_show, acpi_driver_data(device)))
1225 		return -ENODEV;
1226 	if (!proc_create_single_data("state", S_IRUGO, acpi_device_dir(device),
1227 			acpi_battery_state_proc_show, acpi_driver_data(device)))
1228 		return -ENODEV;
1229 	if (!proc_create_data("alarm", S_IFREG | S_IRUGO | S_IWUSR,
1230 			acpi_device_dir(device), &acpi_battery_alarm_proc_ops,
1231 			acpi_driver_data(device)))
1232 		return -ENODEV;
1233 	return 0;
1234 }
1235 
1236 static void acpi_battery_remove_fs(struct acpi_device *device)
1237 {
1238 	if (!acpi_device_dir(device))
1239 		return;
1240 	remove_proc_subtree(acpi_device_bid(device), acpi_battery_dir);
1241 	acpi_device_dir(device) = NULL;
1242 }
1243 
1244 #endif
1245 
1246 /* --------------------------------------------------------------------------
1247                                  Driver Interface
1248    -------------------------------------------------------------------------- */
1249 
1250 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1251 {
1252 	struct acpi_battery *battery = acpi_driver_data(device);
1253 	struct power_supply *old;
1254 
1255 	if (!battery)
1256 		return;
1257 	old = battery->bat;
1258 	/*
1259 	* On Acer Aspire V5-573G notifications are sometimes triggered too
1260 	* early. For example, when AC is unplugged and notification is
1261 	* triggered, battery state is still reported as "Full", and changes to
1262 	* "Discharging" only after short delay, without any notification.
1263 	*/
1264 	if (battery_notification_delay_ms > 0)
1265 		msleep(battery_notification_delay_ms);
1266 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1267 		acpi_battery_refresh(battery);
1268 	acpi_battery_update(battery, false);
1269 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1270 					dev_name(&device->dev), event,
1271 					acpi_battery_present(battery));
1272 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1273 	/* acpi_battery_update could remove power_supply object */
1274 	if (old && battery->bat)
1275 		power_supply_changed(battery->bat);
1276 }
1277 
1278 static int battery_notify(struct notifier_block *nb,
1279 			       unsigned long mode, void *_unused)
1280 {
1281 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1282 						    pm_nb);
1283 	int result;
1284 
1285 	switch (mode) {
1286 	case PM_POST_HIBERNATION:
1287 	case PM_POST_SUSPEND:
1288 		if (!acpi_battery_present(battery))
1289 			return 0;
1290 
1291 		if (battery->bat) {
1292 			acpi_battery_refresh(battery);
1293 		} else {
1294 			result = acpi_battery_get_info(battery);
1295 			if (result)
1296 				return result;
1297 
1298 			result = sysfs_add_battery(battery);
1299 			if (result)
1300 				return result;
1301 		}
1302 
1303 		acpi_battery_init_alarm(battery);
1304 		acpi_battery_get_state(battery);
1305 		break;
1306 	}
1307 
1308 	return 0;
1309 }
1310 
1311 static int __init
1312 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1313 {
1314 	battery_bix_broken_package = 1;
1315 	return 0;
1316 }
1317 
1318 static int __init
1319 battery_notification_delay_quirk(const struct dmi_system_id *d)
1320 {
1321 	battery_notification_delay_ms = 1000;
1322 	return 0;
1323 }
1324 
1325 static int __init
1326 battery_ac_is_broken_quirk(const struct dmi_system_id *d)
1327 {
1328 	battery_ac_is_broken = 1;
1329 	return 0;
1330 }
1331 
1332 static int __init
1333 battery_do_not_check_pmic_quirk(const struct dmi_system_id *d)
1334 {
1335 	battery_check_pmic = 0;
1336 	return 0;
1337 }
1338 
1339 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1340 	{
1341 		/* NEC LZ750/LS */
1342 		.callback = battery_bix_broken_package_quirk,
1343 		.matches = {
1344 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1345 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1346 		},
1347 	},
1348 	{
1349 		/* Acer Aspire V5-573G */
1350 		.callback = battery_notification_delay_quirk,
1351 		.matches = {
1352 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1353 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1354 		},
1355 	},
1356 	{
1357 		/* Point of View mobii wintab p800w */
1358 		.callback = battery_ac_is_broken_quirk,
1359 		.matches = {
1360 			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
1361 			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
1362 			DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
1363 			/* Above matches are too generic, add bios-date match */
1364 			DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
1365 		},
1366 	},
1367 	{
1368 		/* ECS EF20EA, AXP288 PMIC but uses separate fuel-gauge */
1369 		.callback = battery_do_not_check_pmic_quirk,
1370 		.matches = {
1371 			DMI_MATCH(DMI_PRODUCT_NAME, "EF20EA"),
1372 		},
1373 	},
1374 	{
1375 		/* Lenovo Ideapad Miix 320, AXP288 PMIC, separate fuel-gauge */
1376 		.callback = battery_do_not_check_pmic_quirk,
1377 		.matches = {
1378 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
1379 			DMI_MATCH(DMI_PRODUCT_NAME, "80XF"),
1380 			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo MIIX 320-10ICR"),
1381 		},
1382 	},
1383 	{},
1384 };
1385 
1386 /*
1387  * Some machines'(E,G Lenovo Z480) ECs are not stable
1388  * during boot up and this causes battery driver fails to be
1389  * probed due to failure of getting battery information
1390  * from EC sometimes. After several retries, the operation
1391  * may work. So add retry code here and 20ms sleep between
1392  * every retries.
1393  */
1394 static int acpi_battery_update_retry(struct acpi_battery *battery)
1395 {
1396 	int retry, ret;
1397 
1398 	for (retry = 5; retry; retry--) {
1399 		ret = acpi_battery_update(battery, false);
1400 		if (!ret)
1401 			break;
1402 
1403 		msleep(20);
1404 	}
1405 	return ret;
1406 }
1407 
1408 static int acpi_battery_add(struct acpi_device *device)
1409 {
1410 	int result = 0;
1411 	struct acpi_battery *battery = NULL;
1412 
1413 	if (!device)
1414 		return -EINVAL;
1415 
1416 	if (device->dep_unmet)
1417 		return -EPROBE_DEFER;
1418 
1419 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1420 	if (!battery)
1421 		return -ENOMEM;
1422 	battery->device = device;
1423 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1424 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1425 	device->driver_data = battery;
1426 	mutex_init(&battery->lock);
1427 	mutex_init(&battery->sysfs_lock);
1428 	if (acpi_has_method(battery->device->handle, "_BIX"))
1429 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1430 
1431 	result = acpi_battery_update_retry(battery);
1432 	if (result)
1433 		goto fail;
1434 
1435 #ifdef CONFIG_ACPI_PROCFS_POWER
1436 	result = acpi_battery_add_fs(device);
1437 	if (result) {
1438 		acpi_battery_remove_fs(device);
1439 		goto fail;
1440 	}
1441 #endif
1442 
1443 	pr_info(PREFIX "%s Slot [%s] (battery %s)\n",
1444 		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
1445 		device->status.battery_present ? "present" : "absent");
1446 
1447 	battery->pm_nb.notifier_call = battery_notify;
1448 	register_pm_notifier(&battery->pm_nb);
1449 
1450 	device_init_wakeup(&device->dev, 1);
1451 
1452 	return result;
1453 
1454 fail:
1455 	sysfs_remove_battery(battery);
1456 	mutex_destroy(&battery->lock);
1457 	mutex_destroy(&battery->sysfs_lock);
1458 	kfree(battery);
1459 	return result;
1460 }
1461 
1462 static int acpi_battery_remove(struct acpi_device *device)
1463 {
1464 	struct acpi_battery *battery = NULL;
1465 
1466 	if (!device || !acpi_driver_data(device))
1467 		return -EINVAL;
1468 	device_init_wakeup(&device->dev, 0);
1469 	battery = acpi_driver_data(device);
1470 	unregister_pm_notifier(&battery->pm_nb);
1471 #ifdef CONFIG_ACPI_PROCFS_POWER
1472 	acpi_battery_remove_fs(device);
1473 #endif
1474 	sysfs_remove_battery(battery);
1475 	mutex_destroy(&battery->lock);
1476 	mutex_destroy(&battery->sysfs_lock);
1477 	kfree(battery);
1478 	return 0;
1479 }
1480 
1481 #ifdef CONFIG_PM_SLEEP
1482 /* this is needed to learn about changes made in suspended state */
1483 static int acpi_battery_resume(struct device *dev)
1484 {
1485 	struct acpi_battery *battery;
1486 
1487 	if (!dev)
1488 		return -EINVAL;
1489 
1490 	battery = acpi_driver_data(to_acpi_device(dev));
1491 	if (!battery)
1492 		return -EINVAL;
1493 
1494 	battery->update_time = 0;
1495 	acpi_battery_update(battery, true);
1496 	return 0;
1497 }
1498 #else
1499 #define acpi_battery_resume NULL
1500 #endif
1501 
1502 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1503 
1504 static struct acpi_driver acpi_battery_driver = {
1505 	.name = "battery",
1506 	.class = ACPI_BATTERY_CLASS,
1507 	.ids = battery_device_ids,
1508 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1509 	.ops = {
1510 		.add = acpi_battery_add,
1511 		.remove = acpi_battery_remove,
1512 		.notify = acpi_battery_notify,
1513 		},
1514 	.drv.pm = &acpi_battery_pm,
1515 };
1516 
1517 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1518 {
1519 	unsigned int i;
1520 	int result;
1521 
1522 	dmi_check_system(bat_dmi_table);
1523 
1524 	if (battery_check_pmic) {
1525 		for (i = 0; i < ARRAY_SIZE(acpi_battery_blacklist); i++)
1526 			if (acpi_dev_present(acpi_battery_blacklist[i], "1", -1)) {
1527 				pr_info(PREFIX ACPI_BATTERY_DEVICE_NAME
1528 					": found native %s PMIC, not loading\n",
1529 					acpi_battery_blacklist[i]);
1530 				return;
1531 			}
1532 	}
1533 
1534 #ifdef CONFIG_ACPI_PROCFS_POWER
1535 	acpi_battery_dir = acpi_lock_battery_dir();
1536 	if (!acpi_battery_dir)
1537 		return;
1538 #endif
1539 	result = acpi_bus_register_driver(&acpi_battery_driver);
1540 #ifdef CONFIG_ACPI_PROCFS_POWER
1541 	if (result < 0)
1542 		acpi_unlock_battery_dir(acpi_battery_dir);
1543 #endif
1544 	battery_driver_registered = (result == 0);
1545 }
1546 
1547 static int __init acpi_battery_init(void)
1548 {
1549 	if (acpi_disabled)
1550 		return -ENODEV;
1551 
1552 	async_cookie = async_schedule(acpi_battery_init_async, NULL);
1553 	return 0;
1554 }
1555 
1556 static void __exit acpi_battery_exit(void)
1557 {
1558 	async_synchronize_cookie(async_cookie + 1);
1559 	if (battery_driver_registered) {
1560 		acpi_bus_unregister_driver(&acpi_battery_driver);
1561 		battery_hook_exit();
1562 	}
1563 #ifdef CONFIG_ACPI_PROCFS_POWER
1564 	if (acpi_battery_dir)
1565 		acpi_unlock_battery_dir(acpi_battery_dir);
1566 #endif
1567 }
1568 
1569 module_init(acpi_battery_init);
1570 module_exit(acpi_battery_exit);
1571