xref: /openbmc/linux/drivers/acpi/battery.c (revision f7c35abe)
1 /*
2  *  battery.c - ACPI Battery Driver (Revision: 2.0)
3  *
4  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
6  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
7  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/jiffies.h>
29 #include <linux/async.h>
30 #include <linux/dmi.h>
31 #include <linux/delay.h>
32 #include <linux/slab.h>
33 #include <linux/suspend.h>
34 #include <asm/unaligned.h>
35 
36 #ifdef CONFIG_ACPI_PROCFS_POWER
37 #include <linux/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/uaccess.h>
40 #endif
41 
42 #include <linux/acpi.h>
43 #include <linux/power_supply.h>
44 
45 #include "battery.h"
46 
47 #define PREFIX "ACPI: "
48 
49 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
50 
51 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
52 
53 /* Battery power unit: 0 means mW, 1 means mA */
54 #define ACPI_BATTERY_POWER_UNIT_MA	1
55 
56 #define ACPI_BATTERY_STATE_DISCHARGING	0x1
57 #define ACPI_BATTERY_STATE_CHARGING	0x2
58 #define ACPI_BATTERY_STATE_CRITICAL	0x4
59 
60 #define _COMPONENT		ACPI_BATTERY_COMPONENT
61 
62 ACPI_MODULE_NAME("battery");
63 
64 MODULE_AUTHOR("Paul Diefenbaugh");
65 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
66 MODULE_DESCRIPTION("ACPI Battery Driver");
67 MODULE_LICENSE("GPL");
68 
69 static async_cookie_t async_cookie;
70 static int battery_bix_broken_package;
71 static int battery_notification_delay_ms;
72 static unsigned int cache_time = 1000;
73 module_param(cache_time, uint, 0644);
74 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
75 
76 #ifdef CONFIG_ACPI_PROCFS_POWER
77 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
78 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
79 
80 enum acpi_battery_files {
81 	info_tag = 0,
82 	state_tag,
83 	alarm_tag,
84 	ACPI_BATTERY_NUMFILES,
85 };
86 
87 #endif
88 
89 static const struct acpi_device_id battery_device_ids[] = {
90 	{"PNP0C0A", 0},
91 	{"", 0},
92 };
93 
94 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
95 
96 enum {
97 	ACPI_BATTERY_ALARM_PRESENT,
98 	ACPI_BATTERY_XINFO_PRESENT,
99 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
100 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
101 	   switches between mWh and mAh depending on whether the system
102 	   is running on battery or not.  When mAh is the unit, most
103 	   reported values are incorrect and need to be adjusted by
104 	   10000/design_voltage.  Verified on x201, t410, t410s, and x220.
105 	   Pre-2010 and 2012 models appear to always report in mWh and
106 	   are thus unaffected (tested with t42, t61, t500, x200, x300,
107 	   and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
108 	   the 2011 models that fixes the issue (tested on x220 with a
109 	   post-1.29 BIOS), but as of Nov. 2012, no such update is
110 	   available for the 2010 models.  */
111 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
112 };
113 
114 struct acpi_battery {
115 	struct mutex lock;
116 	struct mutex sysfs_lock;
117 	struct power_supply *bat;
118 	struct power_supply_desc bat_desc;
119 	struct acpi_device *device;
120 	struct notifier_block pm_nb;
121 	unsigned long update_time;
122 	int revision;
123 	int rate_now;
124 	int capacity_now;
125 	int voltage_now;
126 	int design_capacity;
127 	int full_charge_capacity;
128 	int technology;
129 	int design_voltage;
130 	int design_capacity_warning;
131 	int design_capacity_low;
132 	int cycle_count;
133 	int measurement_accuracy;
134 	int max_sampling_time;
135 	int min_sampling_time;
136 	int max_averaging_interval;
137 	int min_averaging_interval;
138 	int capacity_granularity_1;
139 	int capacity_granularity_2;
140 	int alarm;
141 	char model_number[32];
142 	char serial_number[32];
143 	char type[32];
144 	char oem_info[32];
145 	int state;
146 	int power_unit;
147 	unsigned long flags;
148 };
149 
150 #define to_acpi_battery(x) power_supply_get_drvdata(x)
151 
152 static inline int acpi_battery_present(struct acpi_battery *battery)
153 {
154 	return battery->device->status.battery_present;
155 }
156 
157 static int acpi_battery_technology(struct acpi_battery *battery)
158 {
159 	if (!strcasecmp("NiCd", battery->type))
160 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
161 	if (!strcasecmp("NiMH", battery->type))
162 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
163 	if (!strcasecmp("LION", battery->type))
164 		return POWER_SUPPLY_TECHNOLOGY_LION;
165 	if (!strncasecmp("LI-ION", battery->type, 6))
166 		return POWER_SUPPLY_TECHNOLOGY_LION;
167 	if (!strcasecmp("LiP", battery->type))
168 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
169 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
170 }
171 
172 static int acpi_battery_get_state(struct acpi_battery *battery);
173 
174 static int acpi_battery_is_charged(struct acpi_battery *battery)
175 {
176 	/* charging, discharging or critical low */
177 	if (battery->state != 0)
178 		return 0;
179 
180 	/* battery not reporting charge */
181 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
182 	    battery->capacity_now == 0)
183 		return 0;
184 
185 	/* good batteries update full_charge as the batteries degrade */
186 	if (battery->full_charge_capacity == battery->capacity_now)
187 		return 1;
188 
189 	/* fallback to using design values for broken batteries */
190 	if (battery->design_capacity == battery->capacity_now)
191 		return 1;
192 
193 	/* we don't do any sort of metric based on percentages */
194 	return 0;
195 }
196 
197 static int acpi_battery_get_property(struct power_supply *psy,
198 				     enum power_supply_property psp,
199 				     union power_supply_propval *val)
200 {
201 	int ret = 0;
202 	struct acpi_battery *battery = to_acpi_battery(psy);
203 
204 	if (acpi_battery_present(battery)) {
205 		/* run battery update only if it is present */
206 		acpi_battery_get_state(battery);
207 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
208 		return -ENODEV;
209 	switch (psp) {
210 	case POWER_SUPPLY_PROP_STATUS:
211 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
212 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
213 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
214 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
215 		else if (acpi_battery_is_charged(battery))
216 			val->intval = POWER_SUPPLY_STATUS_FULL;
217 		else
218 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
219 		break;
220 	case POWER_SUPPLY_PROP_PRESENT:
221 		val->intval = acpi_battery_present(battery);
222 		break;
223 	case POWER_SUPPLY_PROP_TECHNOLOGY:
224 		val->intval = acpi_battery_technology(battery);
225 		break;
226 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
227 		val->intval = battery->cycle_count;
228 		break;
229 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
230 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
231 			ret = -ENODEV;
232 		else
233 			val->intval = battery->design_voltage * 1000;
234 		break;
235 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
236 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
237 			ret = -ENODEV;
238 		else
239 			val->intval = battery->voltage_now * 1000;
240 		break;
241 	case POWER_SUPPLY_PROP_CURRENT_NOW:
242 	case POWER_SUPPLY_PROP_POWER_NOW:
243 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
244 			ret = -ENODEV;
245 		else
246 			val->intval = battery->rate_now * 1000;
247 		break;
248 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
249 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
250 		if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
251 			ret = -ENODEV;
252 		else
253 			val->intval = battery->design_capacity * 1000;
254 		break;
255 	case POWER_SUPPLY_PROP_CHARGE_FULL:
256 	case POWER_SUPPLY_PROP_ENERGY_FULL:
257 		if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
258 			ret = -ENODEV;
259 		else
260 			val->intval = battery->full_charge_capacity * 1000;
261 		break;
262 	case POWER_SUPPLY_PROP_CHARGE_NOW:
263 	case POWER_SUPPLY_PROP_ENERGY_NOW:
264 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
265 			ret = -ENODEV;
266 		else
267 			val->intval = battery->capacity_now * 1000;
268 		break;
269 	case POWER_SUPPLY_PROP_CAPACITY:
270 		if (battery->capacity_now && battery->full_charge_capacity)
271 			val->intval = battery->capacity_now * 100/
272 					battery->full_charge_capacity;
273 		else
274 			val->intval = 0;
275 		break;
276 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
277 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
278 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
279 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
280 			(battery->capacity_now <= battery->alarm))
281 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
282 		else if (acpi_battery_is_charged(battery))
283 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
284 		else
285 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
286 		break;
287 	case POWER_SUPPLY_PROP_MODEL_NAME:
288 		val->strval = battery->model_number;
289 		break;
290 	case POWER_SUPPLY_PROP_MANUFACTURER:
291 		val->strval = battery->oem_info;
292 		break;
293 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
294 		val->strval = battery->serial_number;
295 		break;
296 	default:
297 		ret = -EINVAL;
298 	}
299 	return ret;
300 }
301 
302 static enum power_supply_property charge_battery_props[] = {
303 	POWER_SUPPLY_PROP_STATUS,
304 	POWER_SUPPLY_PROP_PRESENT,
305 	POWER_SUPPLY_PROP_TECHNOLOGY,
306 	POWER_SUPPLY_PROP_CYCLE_COUNT,
307 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
308 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
309 	POWER_SUPPLY_PROP_CURRENT_NOW,
310 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
311 	POWER_SUPPLY_PROP_CHARGE_FULL,
312 	POWER_SUPPLY_PROP_CHARGE_NOW,
313 	POWER_SUPPLY_PROP_CAPACITY,
314 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
315 	POWER_SUPPLY_PROP_MODEL_NAME,
316 	POWER_SUPPLY_PROP_MANUFACTURER,
317 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
318 };
319 
320 static enum power_supply_property energy_battery_props[] = {
321 	POWER_SUPPLY_PROP_STATUS,
322 	POWER_SUPPLY_PROP_PRESENT,
323 	POWER_SUPPLY_PROP_TECHNOLOGY,
324 	POWER_SUPPLY_PROP_CYCLE_COUNT,
325 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
326 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
327 	POWER_SUPPLY_PROP_POWER_NOW,
328 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
329 	POWER_SUPPLY_PROP_ENERGY_FULL,
330 	POWER_SUPPLY_PROP_ENERGY_NOW,
331 	POWER_SUPPLY_PROP_CAPACITY,
332 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
333 	POWER_SUPPLY_PROP_MODEL_NAME,
334 	POWER_SUPPLY_PROP_MANUFACTURER,
335 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
336 };
337 
338 /* --------------------------------------------------------------------------
339                                Battery Management
340    -------------------------------------------------------------------------- */
341 struct acpi_offsets {
342 	size_t offset;		/* offset inside struct acpi_sbs_battery */
343 	u8 mode;		/* int or string? */
344 };
345 
346 static const struct acpi_offsets state_offsets[] = {
347 	{offsetof(struct acpi_battery, state), 0},
348 	{offsetof(struct acpi_battery, rate_now), 0},
349 	{offsetof(struct acpi_battery, capacity_now), 0},
350 	{offsetof(struct acpi_battery, voltage_now), 0},
351 };
352 
353 static const struct acpi_offsets info_offsets[] = {
354 	{offsetof(struct acpi_battery, power_unit), 0},
355 	{offsetof(struct acpi_battery, design_capacity), 0},
356 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
357 	{offsetof(struct acpi_battery, technology), 0},
358 	{offsetof(struct acpi_battery, design_voltage), 0},
359 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
360 	{offsetof(struct acpi_battery, design_capacity_low), 0},
361 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
362 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
363 	{offsetof(struct acpi_battery, model_number), 1},
364 	{offsetof(struct acpi_battery, serial_number), 1},
365 	{offsetof(struct acpi_battery, type), 1},
366 	{offsetof(struct acpi_battery, oem_info), 1},
367 };
368 
369 static const struct acpi_offsets extended_info_offsets[] = {
370 	{offsetof(struct acpi_battery, revision), 0},
371 	{offsetof(struct acpi_battery, power_unit), 0},
372 	{offsetof(struct acpi_battery, design_capacity), 0},
373 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
374 	{offsetof(struct acpi_battery, technology), 0},
375 	{offsetof(struct acpi_battery, design_voltage), 0},
376 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
377 	{offsetof(struct acpi_battery, design_capacity_low), 0},
378 	{offsetof(struct acpi_battery, cycle_count), 0},
379 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
380 	{offsetof(struct acpi_battery, max_sampling_time), 0},
381 	{offsetof(struct acpi_battery, min_sampling_time), 0},
382 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
383 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
384 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
385 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
386 	{offsetof(struct acpi_battery, model_number), 1},
387 	{offsetof(struct acpi_battery, serial_number), 1},
388 	{offsetof(struct acpi_battery, type), 1},
389 	{offsetof(struct acpi_battery, oem_info), 1},
390 };
391 
392 static int extract_package(struct acpi_battery *battery,
393 			   union acpi_object *package,
394 			   const struct acpi_offsets *offsets, int num)
395 {
396 	int i;
397 	union acpi_object *element;
398 	if (package->type != ACPI_TYPE_PACKAGE)
399 		return -EFAULT;
400 	for (i = 0; i < num; ++i) {
401 		if (package->package.count <= i)
402 			return -EFAULT;
403 		element = &package->package.elements[i];
404 		if (offsets[i].mode) {
405 			u8 *ptr = (u8 *)battery + offsets[i].offset;
406 			if (element->type == ACPI_TYPE_STRING ||
407 			    element->type == ACPI_TYPE_BUFFER)
408 				strncpy(ptr, element->string.pointer, 32);
409 			else if (element->type == ACPI_TYPE_INTEGER) {
410 				strncpy(ptr, (u8 *)&element->integer.value,
411 					sizeof(u64));
412 				ptr[sizeof(u64)] = 0;
413 			} else
414 				*ptr = 0; /* don't have value */
415 		} else {
416 			int *x = (int *)((u8 *)battery + offsets[i].offset);
417 			*x = (element->type == ACPI_TYPE_INTEGER) ?
418 				element->integer.value : -1;
419 		}
420 	}
421 	return 0;
422 }
423 
424 static int acpi_battery_get_status(struct acpi_battery *battery)
425 {
426 	if (acpi_bus_get_status(battery->device)) {
427 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
428 		return -ENODEV;
429 	}
430 	return 0;
431 }
432 
433 
434 static int extract_battery_info(const int use_bix,
435 			 struct acpi_battery *battery,
436 			 const struct acpi_buffer *buffer)
437 {
438 	int result = -EFAULT;
439 
440 	if (use_bix && battery_bix_broken_package)
441 		result = extract_package(battery, buffer->pointer,
442 				extended_info_offsets + 1,
443 				ARRAY_SIZE(extended_info_offsets) - 1);
444 	else if (use_bix)
445 		result = extract_package(battery, buffer->pointer,
446 				extended_info_offsets,
447 				ARRAY_SIZE(extended_info_offsets));
448 	else
449 		result = extract_package(battery, buffer->pointer,
450 				info_offsets, ARRAY_SIZE(info_offsets));
451 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
452 		battery->full_charge_capacity = battery->design_capacity;
453 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
454 	    battery->power_unit && battery->design_voltage) {
455 		battery->design_capacity = battery->design_capacity *
456 		    10000 / battery->design_voltage;
457 		battery->full_charge_capacity = battery->full_charge_capacity *
458 		    10000 / battery->design_voltage;
459 		battery->design_capacity_warning =
460 		    battery->design_capacity_warning *
461 		    10000 / battery->design_voltage;
462 		/* Curiously, design_capacity_low, unlike the rest of them,
463 		   is correct.  */
464 		/* capacity_granularity_* equal 1 on the systems tested, so
465 		   it's impossible to tell if they would need an adjustment
466 		   or not if their values were higher.  */
467 	}
468 	return result;
469 }
470 
471 static int acpi_battery_get_info(struct acpi_battery *battery)
472 {
473 	const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
474 	int use_bix;
475 	int result = -ENODEV;
476 
477 	if (!acpi_battery_present(battery))
478 		return 0;
479 
480 
481 	for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
482 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
483 		acpi_status status = AE_ERROR;
484 
485 		mutex_lock(&battery->lock);
486 		status = acpi_evaluate_object(battery->device->handle,
487 					      use_bix ? "_BIX":"_BIF",
488 					      NULL, &buffer);
489 		mutex_unlock(&battery->lock);
490 
491 		if (ACPI_FAILURE(status)) {
492 			ACPI_EXCEPTION((AE_INFO, status, "Evaluating %s",
493 					use_bix ? "_BIX":"_BIF"));
494 		} else {
495 			result = extract_battery_info(use_bix,
496 						      battery,
497 						      &buffer);
498 
499 			kfree(buffer.pointer);
500 			break;
501 		}
502 	}
503 
504 	if (!result && !use_bix && xinfo)
505 		pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
506 
507 	return result;
508 }
509 
510 static int acpi_battery_get_state(struct acpi_battery *battery)
511 {
512 	int result = 0;
513 	acpi_status status = 0;
514 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
515 
516 	if (!acpi_battery_present(battery))
517 		return 0;
518 
519 	if (battery->update_time &&
520 	    time_before(jiffies, battery->update_time +
521 			msecs_to_jiffies(cache_time)))
522 		return 0;
523 
524 	mutex_lock(&battery->lock);
525 	status = acpi_evaluate_object(battery->device->handle, "_BST",
526 				      NULL, &buffer);
527 	mutex_unlock(&battery->lock);
528 
529 	if (ACPI_FAILURE(status)) {
530 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
531 		return -ENODEV;
532 	}
533 
534 	result = extract_package(battery, buffer.pointer,
535 				 state_offsets, ARRAY_SIZE(state_offsets));
536 	battery->update_time = jiffies;
537 	kfree(buffer.pointer);
538 
539 	/* For buggy DSDTs that report negative 16-bit values for either
540 	 * charging or discharging current and/or report 0 as 65536
541 	 * due to bad math.
542 	 */
543 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
544 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
545 		(s16)(battery->rate_now) < 0) {
546 		battery->rate_now = abs((s16)battery->rate_now);
547 		printk_once(KERN_WARNING FW_BUG
548 			    "battery: (dis)charge rate invalid.\n");
549 	}
550 
551 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
552 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
553 		battery->capacity_now = (battery->capacity_now *
554 				battery->full_charge_capacity) / 100;
555 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
556 	    battery->power_unit && battery->design_voltage) {
557 		battery->capacity_now = battery->capacity_now *
558 		    10000 / battery->design_voltage;
559 	}
560 	return result;
561 }
562 
563 static int acpi_battery_set_alarm(struct acpi_battery *battery)
564 {
565 	acpi_status status = 0;
566 
567 	if (!acpi_battery_present(battery) ||
568 	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
569 		return -ENODEV;
570 
571 	mutex_lock(&battery->lock);
572 	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
573 					    battery->alarm);
574 	mutex_unlock(&battery->lock);
575 
576 	if (ACPI_FAILURE(status))
577 		return -ENODEV;
578 
579 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
580 	return 0;
581 }
582 
583 static int acpi_battery_init_alarm(struct acpi_battery *battery)
584 {
585 	/* See if alarms are supported, and if so, set default */
586 	if (!acpi_has_method(battery->device->handle, "_BTP")) {
587 		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
588 		return 0;
589 	}
590 	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
591 	if (!battery->alarm)
592 		battery->alarm = battery->design_capacity_warning;
593 	return acpi_battery_set_alarm(battery);
594 }
595 
596 static ssize_t acpi_battery_alarm_show(struct device *dev,
597 					struct device_attribute *attr,
598 					char *buf)
599 {
600 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
601 	return sprintf(buf, "%d\n", battery->alarm * 1000);
602 }
603 
604 static ssize_t acpi_battery_alarm_store(struct device *dev,
605 					struct device_attribute *attr,
606 					const char *buf, size_t count)
607 {
608 	unsigned long x;
609 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
610 	if (sscanf(buf, "%lu\n", &x) == 1)
611 		battery->alarm = x/1000;
612 	if (acpi_battery_present(battery))
613 		acpi_battery_set_alarm(battery);
614 	return count;
615 }
616 
617 static struct device_attribute alarm_attr = {
618 	.attr = {.name = "alarm", .mode = 0644},
619 	.show = acpi_battery_alarm_show,
620 	.store = acpi_battery_alarm_store,
621 };
622 
623 static int sysfs_add_battery(struct acpi_battery *battery)
624 {
625 	struct power_supply_config psy_cfg = { .drv_data = battery, };
626 
627 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
628 		battery->bat_desc.properties = charge_battery_props;
629 		battery->bat_desc.num_properties =
630 			ARRAY_SIZE(charge_battery_props);
631 	} else {
632 		battery->bat_desc.properties = energy_battery_props;
633 		battery->bat_desc.num_properties =
634 			ARRAY_SIZE(energy_battery_props);
635 	}
636 
637 	battery->bat_desc.name = acpi_device_bid(battery->device);
638 	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
639 	battery->bat_desc.get_property = acpi_battery_get_property;
640 
641 	battery->bat = power_supply_register_no_ws(&battery->device->dev,
642 				&battery->bat_desc, &psy_cfg);
643 
644 	if (IS_ERR(battery->bat)) {
645 		int result = PTR_ERR(battery->bat);
646 
647 		battery->bat = NULL;
648 		return result;
649 	}
650 	return device_create_file(&battery->bat->dev, &alarm_attr);
651 }
652 
653 static void sysfs_remove_battery(struct acpi_battery *battery)
654 {
655 	mutex_lock(&battery->sysfs_lock);
656 	if (!battery->bat) {
657 		mutex_unlock(&battery->sysfs_lock);
658 		return;
659 	}
660 
661 	device_remove_file(&battery->bat->dev, &alarm_attr);
662 	power_supply_unregister(battery->bat);
663 	battery->bat = NULL;
664 	mutex_unlock(&battery->sysfs_lock);
665 }
666 
667 static void find_battery(const struct dmi_header *dm, void *private)
668 {
669 	struct acpi_battery *battery = (struct acpi_battery *)private;
670 	/* Note: the hardcoded offsets below have been extracted from
671 	   the source code of dmidecode.  */
672 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
673 		const u8 *dmi_data = (const u8 *)(dm + 1);
674 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
675 		if (dm->length >= 18)
676 			dmi_capacity *= dmi_data[17];
677 		if (battery->design_capacity * battery->design_voltage / 1000
678 		    != dmi_capacity &&
679 		    battery->design_capacity * 10 == dmi_capacity)
680 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
681 				&battery->flags);
682 	}
683 }
684 
685 /*
686  * According to the ACPI spec, some kinds of primary batteries can
687  * report percentage battery remaining capacity directly to OS.
688  * In this case, it reports the Last Full Charged Capacity == 100
689  * and BatteryPresentRate == 0xFFFFFFFF.
690  *
691  * Now we found some battery reports percentage remaining capacity
692  * even if it's rechargeable.
693  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
694  *
695  * Handle this correctly so that they won't break userspace.
696  */
697 static void acpi_battery_quirks(struct acpi_battery *battery)
698 {
699 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
700 		return;
701 
702 	if (battery->full_charge_capacity == 100 &&
703 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
704 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
705 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
706 		battery->full_charge_capacity = battery->design_capacity;
707 		battery->capacity_now = (battery->capacity_now *
708 				battery->full_charge_capacity) / 100;
709 	}
710 
711 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
712 		return;
713 
714 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
715 		const char *s;
716 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
717 		if (s && !strncasecmp(s, "ThinkPad", 8)) {
718 			dmi_walk(find_battery, battery);
719 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
720 				     &battery->flags) &&
721 			    battery->design_voltage) {
722 				battery->design_capacity =
723 				    battery->design_capacity *
724 				    10000 / battery->design_voltage;
725 				battery->full_charge_capacity =
726 				    battery->full_charge_capacity *
727 				    10000 / battery->design_voltage;
728 				battery->design_capacity_warning =
729 				    battery->design_capacity_warning *
730 				    10000 / battery->design_voltage;
731 				battery->capacity_now = battery->capacity_now *
732 				    10000 / battery->design_voltage;
733 			}
734 		}
735 	}
736 }
737 
738 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
739 {
740 	int result, old_present = acpi_battery_present(battery);
741 	result = acpi_battery_get_status(battery);
742 	if (result)
743 		return result;
744 	if (!acpi_battery_present(battery)) {
745 		sysfs_remove_battery(battery);
746 		battery->update_time = 0;
747 		return 0;
748 	}
749 
750 	if (resume)
751 		return 0;
752 
753 	if (!battery->update_time ||
754 	    old_present != acpi_battery_present(battery)) {
755 		result = acpi_battery_get_info(battery);
756 		if (result)
757 			return result;
758 		acpi_battery_init_alarm(battery);
759 	}
760 
761 	result = acpi_battery_get_state(battery);
762 	if (result)
763 		return result;
764 	acpi_battery_quirks(battery);
765 
766 	if (!battery->bat) {
767 		result = sysfs_add_battery(battery);
768 		if (result)
769 			return result;
770 	}
771 
772 	/*
773 	 * Wakeup the system if battery is critical low
774 	 * or lower than the alarm level
775 	 */
776 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
777 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
778             (battery->capacity_now <= battery->alarm)))
779 		pm_wakeup_event(&battery->device->dev, 0);
780 
781 	return result;
782 }
783 
784 static void acpi_battery_refresh(struct acpi_battery *battery)
785 {
786 	int power_unit;
787 
788 	if (!battery->bat)
789 		return;
790 
791 	power_unit = battery->power_unit;
792 
793 	acpi_battery_get_info(battery);
794 
795 	if (power_unit == battery->power_unit)
796 		return;
797 
798 	/* The battery has changed its reporting units. */
799 	sysfs_remove_battery(battery);
800 	sysfs_add_battery(battery);
801 }
802 
803 /* --------------------------------------------------------------------------
804                               FS Interface (/proc)
805    -------------------------------------------------------------------------- */
806 
807 #ifdef CONFIG_ACPI_PROCFS_POWER
808 static struct proc_dir_entry *acpi_battery_dir;
809 
810 static const char *acpi_battery_units(const struct acpi_battery *battery)
811 {
812 	return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
813 		"mA" : "mW";
814 }
815 
816 static int acpi_battery_print_info(struct seq_file *seq, int result)
817 {
818 	struct acpi_battery *battery = seq->private;
819 
820 	if (result)
821 		goto end;
822 
823 	seq_printf(seq, "present:                 %s\n",
824 		   acpi_battery_present(battery) ? "yes" : "no");
825 	if (!acpi_battery_present(battery))
826 		goto end;
827 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
828 		seq_printf(seq, "design capacity:         unknown\n");
829 	else
830 		seq_printf(seq, "design capacity:         %d %sh\n",
831 			   battery->design_capacity,
832 			   acpi_battery_units(battery));
833 
834 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
835 		seq_printf(seq, "last full capacity:      unknown\n");
836 	else
837 		seq_printf(seq, "last full capacity:      %d %sh\n",
838 			   battery->full_charge_capacity,
839 			   acpi_battery_units(battery));
840 
841 	seq_printf(seq, "battery technology:      %srechargeable\n",
842 		   (!battery->technology)?"non-":"");
843 
844 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
845 		seq_printf(seq, "design voltage:          unknown\n");
846 	else
847 		seq_printf(seq, "design voltage:          %d mV\n",
848 			   battery->design_voltage);
849 	seq_printf(seq, "design capacity warning: %d %sh\n",
850 		   battery->design_capacity_warning,
851 		   acpi_battery_units(battery));
852 	seq_printf(seq, "design capacity low:     %d %sh\n",
853 		   battery->design_capacity_low,
854 		   acpi_battery_units(battery));
855 	seq_printf(seq, "cycle count:		  %i\n", battery->cycle_count);
856 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
857 		   battery->capacity_granularity_1,
858 		   acpi_battery_units(battery));
859 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
860 		   battery->capacity_granularity_2,
861 		   acpi_battery_units(battery));
862 	seq_printf(seq, "model number:            %s\n", battery->model_number);
863 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
864 	seq_printf(seq, "battery type:            %s\n", battery->type);
865 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
866       end:
867 	if (result)
868 		seq_printf(seq, "ERROR: Unable to read battery info\n");
869 	return result;
870 }
871 
872 static int acpi_battery_print_state(struct seq_file *seq, int result)
873 {
874 	struct acpi_battery *battery = seq->private;
875 
876 	if (result)
877 		goto end;
878 
879 	seq_printf(seq, "present:                 %s\n",
880 		   acpi_battery_present(battery) ? "yes" : "no");
881 	if (!acpi_battery_present(battery))
882 		goto end;
883 
884 	seq_printf(seq, "capacity state:          %s\n",
885 			(battery->state & 0x04) ? "critical" : "ok");
886 	if ((battery->state & 0x01) && (battery->state & 0x02))
887 		seq_printf(seq,
888 			   "charging state:          charging/discharging\n");
889 	else if (battery->state & 0x01)
890 		seq_printf(seq, "charging state:          discharging\n");
891 	else if (battery->state & 0x02)
892 		seq_printf(seq, "charging state:          charging\n");
893 	else
894 		seq_printf(seq, "charging state:          charged\n");
895 
896 	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
897 		seq_printf(seq, "present rate:            unknown\n");
898 	else
899 		seq_printf(seq, "present rate:            %d %s\n",
900 			   battery->rate_now, acpi_battery_units(battery));
901 
902 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
903 		seq_printf(seq, "remaining capacity:      unknown\n");
904 	else
905 		seq_printf(seq, "remaining capacity:      %d %sh\n",
906 			   battery->capacity_now, acpi_battery_units(battery));
907 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
908 		seq_printf(seq, "present voltage:         unknown\n");
909 	else
910 		seq_printf(seq, "present voltage:         %d mV\n",
911 			   battery->voltage_now);
912       end:
913 	if (result)
914 		seq_printf(seq, "ERROR: Unable to read battery state\n");
915 
916 	return result;
917 }
918 
919 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
920 {
921 	struct acpi_battery *battery = seq->private;
922 
923 	if (result)
924 		goto end;
925 
926 	if (!acpi_battery_present(battery)) {
927 		seq_printf(seq, "present:                 no\n");
928 		goto end;
929 	}
930 	seq_printf(seq, "alarm:                   ");
931 	if (!battery->alarm)
932 		seq_printf(seq, "unsupported\n");
933 	else
934 		seq_printf(seq, "%u %sh\n", battery->alarm,
935 				acpi_battery_units(battery));
936       end:
937 	if (result)
938 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
939 	return result;
940 }
941 
942 static ssize_t acpi_battery_write_alarm(struct file *file,
943 					const char __user * buffer,
944 					size_t count, loff_t * ppos)
945 {
946 	int result = 0;
947 	char alarm_string[12] = { '\0' };
948 	struct seq_file *m = file->private_data;
949 	struct acpi_battery *battery = m->private;
950 
951 	if (!battery || (count > sizeof(alarm_string) - 1))
952 		return -EINVAL;
953 	if (!acpi_battery_present(battery)) {
954 		result = -ENODEV;
955 		goto end;
956 	}
957 	if (copy_from_user(alarm_string, buffer, count)) {
958 		result = -EFAULT;
959 		goto end;
960 	}
961 	alarm_string[count] = '\0';
962 	if (kstrtoint(alarm_string, 0, &battery->alarm)) {
963 		result = -EINVAL;
964 		goto end;
965 	}
966 	result = acpi_battery_set_alarm(battery);
967       end:
968 	if (!result)
969 		return count;
970 	return result;
971 }
972 
973 typedef int(*print_func)(struct seq_file *seq, int result);
974 
975 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
976 	acpi_battery_print_info,
977 	acpi_battery_print_state,
978 	acpi_battery_print_alarm,
979 };
980 
981 static int acpi_battery_read(int fid, struct seq_file *seq)
982 {
983 	struct acpi_battery *battery = seq->private;
984 	int result = acpi_battery_update(battery, false);
985 	return acpi_print_funcs[fid](seq, result);
986 }
987 
988 #define DECLARE_FILE_FUNCTIONS(_name) \
989 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
990 { \
991 	return acpi_battery_read(_name##_tag, seq); \
992 } \
993 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
994 { \
995 	return single_open(file, acpi_battery_read_##_name, PDE_DATA(inode)); \
996 }
997 
998 DECLARE_FILE_FUNCTIONS(info);
999 DECLARE_FILE_FUNCTIONS(state);
1000 DECLARE_FILE_FUNCTIONS(alarm);
1001 
1002 #undef DECLARE_FILE_FUNCTIONS
1003 
1004 #define FILE_DESCRIPTION_RO(_name) \
1005 	{ \
1006 	.name = __stringify(_name), \
1007 	.mode = S_IRUGO, \
1008 	.ops = { \
1009 		.open = acpi_battery_##_name##_open_fs, \
1010 		.read = seq_read, \
1011 		.llseek = seq_lseek, \
1012 		.release = single_release, \
1013 		.owner = THIS_MODULE, \
1014 		}, \
1015 	}
1016 
1017 #define FILE_DESCRIPTION_RW(_name) \
1018 	{ \
1019 	.name = __stringify(_name), \
1020 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
1021 	.ops = { \
1022 		.open = acpi_battery_##_name##_open_fs, \
1023 		.read = seq_read, \
1024 		.llseek = seq_lseek, \
1025 		.write = acpi_battery_write_##_name, \
1026 		.release = single_release, \
1027 		.owner = THIS_MODULE, \
1028 		}, \
1029 	}
1030 
1031 static const struct battery_file {
1032 	struct file_operations ops;
1033 	umode_t mode;
1034 	const char *name;
1035 } acpi_battery_file[] = {
1036 	FILE_DESCRIPTION_RO(info),
1037 	FILE_DESCRIPTION_RO(state),
1038 	FILE_DESCRIPTION_RW(alarm),
1039 };
1040 
1041 #undef FILE_DESCRIPTION_RO
1042 #undef FILE_DESCRIPTION_RW
1043 
1044 static int acpi_battery_add_fs(struct acpi_device *device)
1045 {
1046 	struct proc_dir_entry *entry = NULL;
1047 	int i;
1048 
1049 	printk(KERN_WARNING PREFIX "Deprecated procfs I/F for battery is loaded,"
1050 			" please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
1051 	if (!acpi_device_dir(device)) {
1052 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
1053 						     acpi_battery_dir);
1054 		if (!acpi_device_dir(device))
1055 			return -ENODEV;
1056 	}
1057 
1058 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
1059 		entry = proc_create_data(acpi_battery_file[i].name,
1060 					 acpi_battery_file[i].mode,
1061 					 acpi_device_dir(device),
1062 					 &acpi_battery_file[i].ops,
1063 					 acpi_driver_data(device));
1064 		if (!entry)
1065 			return -ENODEV;
1066 	}
1067 	return 0;
1068 }
1069 
1070 static void acpi_battery_remove_fs(struct acpi_device *device)
1071 {
1072 	int i;
1073 	if (!acpi_device_dir(device))
1074 		return;
1075 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
1076 		remove_proc_entry(acpi_battery_file[i].name,
1077 				  acpi_device_dir(device));
1078 
1079 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
1080 	acpi_device_dir(device) = NULL;
1081 }
1082 
1083 #endif
1084 
1085 /* --------------------------------------------------------------------------
1086                                  Driver Interface
1087    -------------------------------------------------------------------------- */
1088 
1089 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1090 {
1091 	struct acpi_battery *battery = acpi_driver_data(device);
1092 	struct power_supply *old;
1093 
1094 	if (!battery)
1095 		return;
1096 	old = battery->bat;
1097 	/*
1098 	* On Acer Aspire V5-573G notifications are sometimes triggered too
1099 	* early. For example, when AC is unplugged and notification is
1100 	* triggered, battery state is still reported as "Full", and changes to
1101 	* "Discharging" only after short delay, without any notification.
1102 	*/
1103 	if (battery_notification_delay_ms > 0)
1104 		msleep(battery_notification_delay_ms);
1105 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1106 		acpi_battery_refresh(battery);
1107 	acpi_battery_update(battery, false);
1108 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1109 					dev_name(&device->dev), event,
1110 					acpi_battery_present(battery));
1111 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1112 	/* acpi_battery_update could remove power_supply object */
1113 	if (old && battery->bat)
1114 		power_supply_changed(battery->bat);
1115 }
1116 
1117 static int battery_notify(struct notifier_block *nb,
1118 			       unsigned long mode, void *_unused)
1119 {
1120 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1121 						    pm_nb);
1122 	int result;
1123 
1124 	switch (mode) {
1125 	case PM_POST_HIBERNATION:
1126 	case PM_POST_SUSPEND:
1127 		if (!acpi_battery_present(battery))
1128 			return 0;
1129 
1130 		if (!battery->bat) {
1131 			result = acpi_battery_get_info(battery);
1132 			if (result)
1133 				return result;
1134 
1135 			result = sysfs_add_battery(battery);
1136 			if (result)
1137 				return result;
1138 		} else
1139 			acpi_battery_refresh(battery);
1140 
1141 		acpi_battery_init_alarm(battery);
1142 		acpi_battery_get_state(battery);
1143 		break;
1144 	}
1145 
1146 	return 0;
1147 }
1148 
1149 static int __init
1150 battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1151 {
1152 	battery_bix_broken_package = 1;
1153 	return 0;
1154 }
1155 
1156 static int __init
1157 battery_notification_delay_quirk(const struct dmi_system_id *d)
1158 {
1159 	battery_notification_delay_ms = 1000;
1160 	return 0;
1161 }
1162 
1163 static const struct dmi_system_id bat_dmi_table[] __initconst = {
1164 	{
1165 		.callback = battery_bix_broken_package_quirk,
1166 		.ident = "NEC LZ750/LS",
1167 		.matches = {
1168 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1169 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1170 		},
1171 	},
1172 	{
1173 		.callback = battery_notification_delay_quirk,
1174 		.ident = "Acer Aspire V5-573G",
1175 		.matches = {
1176 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1177 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1178 		},
1179 	},
1180 	{},
1181 };
1182 
1183 /*
1184  * Some machines'(E,G Lenovo Z480) ECs are not stable
1185  * during boot up and this causes battery driver fails to be
1186  * probed due to failure of getting battery information
1187  * from EC sometimes. After several retries, the operation
1188  * may work. So add retry code here and 20ms sleep between
1189  * every retries.
1190  */
1191 static int acpi_battery_update_retry(struct acpi_battery *battery)
1192 {
1193 	int retry, ret;
1194 
1195 	for (retry = 5; retry; retry--) {
1196 		ret = acpi_battery_update(battery, false);
1197 		if (!ret)
1198 			break;
1199 
1200 		msleep(20);
1201 	}
1202 	return ret;
1203 }
1204 
1205 static int acpi_battery_add(struct acpi_device *device)
1206 {
1207 	int result = 0;
1208 	struct acpi_battery *battery = NULL;
1209 
1210 	if (!device)
1211 		return -EINVAL;
1212 
1213 	if (device->dep_unmet)
1214 		return -EPROBE_DEFER;
1215 
1216 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1217 	if (!battery)
1218 		return -ENOMEM;
1219 	battery->device = device;
1220 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1221 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1222 	device->driver_data = battery;
1223 	mutex_init(&battery->lock);
1224 	mutex_init(&battery->sysfs_lock);
1225 	if (acpi_has_method(battery->device->handle, "_BIX"))
1226 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1227 
1228 	result = acpi_battery_update_retry(battery);
1229 	if (result)
1230 		goto fail;
1231 
1232 #ifdef CONFIG_ACPI_PROCFS_POWER
1233 	result = acpi_battery_add_fs(device);
1234 #endif
1235 	if (result) {
1236 #ifdef CONFIG_ACPI_PROCFS_POWER
1237 		acpi_battery_remove_fs(device);
1238 #endif
1239 		goto fail;
1240 	}
1241 
1242 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
1243 		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
1244 		device->status.battery_present ? "present" : "absent");
1245 
1246 	battery->pm_nb.notifier_call = battery_notify;
1247 	register_pm_notifier(&battery->pm_nb);
1248 
1249 	device_init_wakeup(&device->dev, 1);
1250 
1251 	return result;
1252 
1253 fail:
1254 	sysfs_remove_battery(battery);
1255 	mutex_destroy(&battery->lock);
1256 	mutex_destroy(&battery->sysfs_lock);
1257 	kfree(battery);
1258 	return result;
1259 }
1260 
1261 static int acpi_battery_remove(struct acpi_device *device)
1262 {
1263 	struct acpi_battery *battery = NULL;
1264 
1265 	if (!device || !acpi_driver_data(device))
1266 		return -EINVAL;
1267 	device_init_wakeup(&device->dev, 0);
1268 	battery = acpi_driver_data(device);
1269 	unregister_pm_notifier(&battery->pm_nb);
1270 #ifdef CONFIG_ACPI_PROCFS_POWER
1271 	acpi_battery_remove_fs(device);
1272 #endif
1273 	sysfs_remove_battery(battery);
1274 	mutex_destroy(&battery->lock);
1275 	mutex_destroy(&battery->sysfs_lock);
1276 	kfree(battery);
1277 	return 0;
1278 }
1279 
1280 #ifdef CONFIG_PM_SLEEP
1281 /* this is needed to learn about changes made in suspended state */
1282 static int acpi_battery_resume(struct device *dev)
1283 {
1284 	struct acpi_battery *battery;
1285 
1286 	if (!dev)
1287 		return -EINVAL;
1288 
1289 	battery = acpi_driver_data(to_acpi_device(dev));
1290 	if (!battery)
1291 		return -EINVAL;
1292 
1293 	battery->update_time = 0;
1294 	acpi_battery_update(battery, true);
1295 	return 0;
1296 }
1297 #else
1298 #define acpi_battery_resume NULL
1299 #endif
1300 
1301 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1302 
1303 static struct acpi_driver acpi_battery_driver = {
1304 	.name = "battery",
1305 	.class = ACPI_BATTERY_CLASS,
1306 	.ids = battery_device_ids,
1307 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1308 	.ops = {
1309 		.add = acpi_battery_add,
1310 		.remove = acpi_battery_remove,
1311 		.notify = acpi_battery_notify,
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 	dmi_check_system(bat_dmi_table);
1321 
1322 #ifdef CONFIG_ACPI_PROCFS_POWER
1323 	acpi_battery_dir = acpi_lock_battery_dir();
1324 	if (!acpi_battery_dir)
1325 		return;
1326 #endif
1327 	result = acpi_bus_register_driver(&acpi_battery_driver);
1328 #ifdef CONFIG_ACPI_PROCFS_POWER
1329 	if (result < 0)
1330 		acpi_unlock_battery_dir(acpi_battery_dir);
1331 #endif
1332 }
1333 
1334 static int __init acpi_battery_init(void)
1335 {
1336 	if (acpi_disabled)
1337 		return -ENODEV;
1338 
1339 	async_cookie = async_schedule(acpi_battery_init_async, NULL);
1340 	return 0;
1341 }
1342 
1343 static void __exit acpi_battery_exit(void)
1344 {
1345 	async_synchronize_cookie(async_cookie + 1);
1346 	acpi_bus_unregister_driver(&acpi_battery_driver);
1347 #ifdef CONFIG_ACPI_PROCFS_POWER
1348 	acpi_unlock_battery_dir(acpi_battery_dir);
1349 #endif
1350 }
1351 
1352 module_init(acpi_battery_init);
1353 module_exit(acpi_battery_exit);
1354