xref: /openbmc/linux/drivers/acpi/battery.c (revision 275876e2)
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  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27 
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/jiffies.h>
33 #include <linux/async.h>
34 #include <linux/dmi.h>
35 #include <linux/delay.h>
36 #include <linux/slab.h>
37 #include <linux/suspend.h>
38 #include <asm/unaligned.h>
39 
40 #ifdef CONFIG_ACPI_PROCFS_POWER
41 #include <linux/proc_fs.h>
42 #include <linux/seq_file.h>
43 #include <asm/uaccess.h>
44 #endif
45 
46 #include <linux/acpi.h>
47 #include <linux/power_supply.h>
48 
49 #include "battery.h"
50 
51 #define PREFIX "ACPI: "
52 
53 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
54 
55 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
56 
57 /* Battery power unit: 0 means mW, 1 means mA */
58 #define ACPI_BATTERY_POWER_UNIT_MA	1
59 
60 #define ACPI_BATTERY_STATE_DISCHARGING	0x1
61 #define ACPI_BATTERY_STATE_CHARGING	0x2
62 #define ACPI_BATTERY_STATE_CRITICAL	0x4
63 
64 #define _COMPONENT		ACPI_BATTERY_COMPONENT
65 
66 ACPI_MODULE_NAME("battery");
67 
68 MODULE_AUTHOR("Paul Diefenbaugh");
69 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
70 MODULE_DESCRIPTION("ACPI Battery Driver");
71 MODULE_LICENSE("GPL");
72 
73 static int battery_bix_broken_package;
74 static int battery_notification_delay_ms;
75 static unsigned int cache_time = 1000;
76 module_param(cache_time, uint, 0644);
77 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
78 
79 #ifdef CONFIG_ACPI_PROCFS_POWER
80 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
81 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
82 
83 enum acpi_battery_files {
84 	info_tag = 0,
85 	state_tag,
86 	alarm_tag,
87 	ACPI_BATTERY_NUMFILES,
88 };
89 
90 #endif
91 
92 static const struct acpi_device_id battery_device_ids[] = {
93 	{"PNP0C0A", 0},
94 	{"", 0},
95 };
96 
97 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
98 
99 enum {
100 	ACPI_BATTERY_ALARM_PRESENT,
101 	ACPI_BATTERY_XINFO_PRESENT,
102 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
103 	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
104 	   switches between mWh and mAh depending on whether the system
105 	   is running on battery or not.  When mAh is the unit, most
106 	   reported values are incorrect and need to be adjusted by
107 	   10000/design_voltage.  Verified on x201, t410, t410s, and x220.
108 	   Pre-2010 and 2012 models appear to always report in mWh and
109 	   are thus unaffected (tested with t42, t61, t500, x200, x300,
110 	   and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
111 	   the 2011 models that fixes the issue (tested on x220 with a
112 	   post-1.29 BIOS), but as of Nov. 2012, no such update is
113 	   available for the 2010 models.  */
114 	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
115 };
116 
117 struct acpi_battery {
118 	struct mutex lock;
119 	struct mutex sysfs_lock;
120 	struct power_supply bat;
121 	struct acpi_device *device;
122 	struct notifier_block pm_nb;
123 	unsigned long update_time;
124 	int revision;
125 	int rate_now;
126 	int capacity_now;
127 	int voltage_now;
128 	int design_capacity;
129 	int full_charge_capacity;
130 	int technology;
131 	int design_voltage;
132 	int design_capacity_warning;
133 	int design_capacity_low;
134 	int cycle_count;
135 	int measurement_accuracy;
136 	int max_sampling_time;
137 	int min_sampling_time;
138 	int max_averaging_interval;
139 	int min_averaging_interval;
140 	int capacity_granularity_1;
141 	int capacity_granularity_2;
142 	int alarm;
143 	char model_number[32];
144 	char serial_number[32];
145 	char type[32];
146 	char oem_info[32];
147 	int state;
148 	int power_unit;
149 	unsigned long flags;
150 };
151 
152 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat)
153 
154 static inline int acpi_battery_present(struct acpi_battery *battery)
155 {
156 	return battery->device->status.battery_present;
157 }
158 
159 static int acpi_battery_technology(struct acpi_battery *battery)
160 {
161 	if (!strcasecmp("NiCd", battery->type))
162 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
163 	if (!strcasecmp("NiMH", battery->type))
164 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
165 	if (!strcasecmp("LION", battery->type))
166 		return POWER_SUPPLY_TECHNOLOGY_LION;
167 	if (!strncasecmp("LI-ION", battery->type, 6))
168 		return POWER_SUPPLY_TECHNOLOGY_LION;
169 	if (!strcasecmp("LiP", battery->type))
170 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
171 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
172 }
173 
174 static int acpi_battery_get_state(struct acpi_battery *battery);
175 
176 static int acpi_battery_is_charged(struct acpi_battery *battery)
177 {
178 	/* charging, discharging or critical low */
179 	if (battery->state != 0)
180 		return 0;
181 
182 	/* battery not reporting charge */
183 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
184 	    battery->capacity_now == 0)
185 		return 0;
186 
187 	/* good batteries update full_charge as the batteries degrade */
188 	if (battery->full_charge_capacity == battery->capacity_now)
189 		return 1;
190 
191 	/* fallback to using design values for broken batteries */
192 	if (battery->design_capacity == battery->capacity_now)
193 		return 1;
194 
195 	/* we don't do any sort of metric based on percentages */
196 	return 0;
197 }
198 
199 static int acpi_battery_get_property(struct power_supply *psy,
200 				     enum power_supply_property psp,
201 				     union power_supply_propval *val)
202 {
203 	int ret = 0;
204 	struct acpi_battery *battery = to_acpi_battery(psy);
205 
206 	if (acpi_battery_present(battery)) {
207 		/* run battery update only if it is present */
208 		acpi_battery_get_state(battery);
209 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
210 		return -ENODEV;
211 	switch (psp) {
212 	case POWER_SUPPLY_PROP_STATUS:
213 		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
214 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
215 		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
216 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
217 		else if (acpi_battery_is_charged(battery))
218 			val->intval = POWER_SUPPLY_STATUS_FULL;
219 		else
220 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
221 		break;
222 	case POWER_SUPPLY_PROP_PRESENT:
223 		val->intval = acpi_battery_present(battery);
224 		break;
225 	case POWER_SUPPLY_PROP_TECHNOLOGY:
226 		val->intval = acpi_battery_technology(battery);
227 		break;
228 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
229 		val->intval = battery->cycle_count;
230 		break;
231 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
232 		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
233 			ret = -ENODEV;
234 		else
235 			val->intval = battery->design_voltage * 1000;
236 		break;
237 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
238 		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
239 			ret = -ENODEV;
240 		else
241 			val->intval = battery->voltage_now * 1000;
242 		break;
243 	case POWER_SUPPLY_PROP_CURRENT_NOW:
244 	case POWER_SUPPLY_PROP_POWER_NOW:
245 		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
246 			ret = -ENODEV;
247 		else
248 			val->intval = battery->rate_now * 1000;
249 		break;
250 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
251 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
252 		if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
253 			ret = -ENODEV;
254 		else
255 			val->intval = battery->design_capacity * 1000;
256 		break;
257 	case POWER_SUPPLY_PROP_CHARGE_FULL:
258 	case POWER_SUPPLY_PROP_ENERGY_FULL:
259 		if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
260 			ret = -ENODEV;
261 		else
262 			val->intval = battery->full_charge_capacity * 1000;
263 		break;
264 	case POWER_SUPPLY_PROP_CHARGE_NOW:
265 	case POWER_SUPPLY_PROP_ENERGY_NOW:
266 		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
267 			ret = -ENODEV;
268 		else
269 			val->intval = battery->capacity_now * 1000;
270 		break;
271 	case POWER_SUPPLY_PROP_CAPACITY:
272 		if (battery->capacity_now && battery->full_charge_capacity)
273 			val->intval = battery->capacity_now * 100/
274 					battery->full_charge_capacity;
275 		else
276 			val->intval = 0;
277 		break;
278 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
279 		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
280 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
281 		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
282 			(battery->capacity_now <= battery->alarm))
283 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
284 		else if (acpi_battery_is_charged(battery))
285 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
286 		else
287 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
288 		break;
289 	case POWER_SUPPLY_PROP_MODEL_NAME:
290 		val->strval = battery->model_number;
291 		break;
292 	case POWER_SUPPLY_PROP_MANUFACTURER:
293 		val->strval = battery->oem_info;
294 		break;
295 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
296 		val->strval = battery->serial_number;
297 		break;
298 	default:
299 		ret = -EINVAL;
300 	}
301 	return ret;
302 }
303 
304 static enum power_supply_property charge_battery_props[] = {
305 	POWER_SUPPLY_PROP_STATUS,
306 	POWER_SUPPLY_PROP_PRESENT,
307 	POWER_SUPPLY_PROP_TECHNOLOGY,
308 	POWER_SUPPLY_PROP_CYCLE_COUNT,
309 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
310 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
311 	POWER_SUPPLY_PROP_CURRENT_NOW,
312 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
313 	POWER_SUPPLY_PROP_CHARGE_FULL,
314 	POWER_SUPPLY_PROP_CHARGE_NOW,
315 	POWER_SUPPLY_PROP_CAPACITY,
316 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
317 	POWER_SUPPLY_PROP_MODEL_NAME,
318 	POWER_SUPPLY_PROP_MANUFACTURER,
319 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
320 };
321 
322 static enum power_supply_property energy_battery_props[] = {
323 	POWER_SUPPLY_PROP_STATUS,
324 	POWER_SUPPLY_PROP_PRESENT,
325 	POWER_SUPPLY_PROP_TECHNOLOGY,
326 	POWER_SUPPLY_PROP_CYCLE_COUNT,
327 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
328 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
329 	POWER_SUPPLY_PROP_POWER_NOW,
330 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
331 	POWER_SUPPLY_PROP_ENERGY_FULL,
332 	POWER_SUPPLY_PROP_ENERGY_NOW,
333 	POWER_SUPPLY_PROP_CAPACITY,
334 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
335 	POWER_SUPPLY_PROP_MODEL_NAME,
336 	POWER_SUPPLY_PROP_MANUFACTURER,
337 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
338 };
339 
340 #ifdef CONFIG_ACPI_PROCFS_POWER
341 inline char *acpi_battery_units(struct acpi_battery *battery)
342 {
343 	return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
344 		"mA" : "mW";
345 }
346 #endif
347 
348 /* --------------------------------------------------------------------------
349                                Battery Management
350    -------------------------------------------------------------------------- */
351 struct acpi_offsets {
352 	size_t offset;		/* offset inside struct acpi_sbs_battery */
353 	u8 mode;		/* int or string? */
354 };
355 
356 static struct acpi_offsets state_offsets[] = {
357 	{offsetof(struct acpi_battery, state), 0},
358 	{offsetof(struct acpi_battery, rate_now), 0},
359 	{offsetof(struct acpi_battery, capacity_now), 0},
360 	{offsetof(struct acpi_battery, voltage_now), 0},
361 };
362 
363 static struct acpi_offsets info_offsets[] = {
364 	{offsetof(struct acpi_battery, power_unit), 0},
365 	{offsetof(struct acpi_battery, design_capacity), 0},
366 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
367 	{offsetof(struct acpi_battery, technology), 0},
368 	{offsetof(struct acpi_battery, design_voltage), 0},
369 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
370 	{offsetof(struct acpi_battery, design_capacity_low), 0},
371 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
372 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
373 	{offsetof(struct acpi_battery, model_number), 1},
374 	{offsetof(struct acpi_battery, serial_number), 1},
375 	{offsetof(struct acpi_battery, type), 1},
376 	{offsetof(struct acpi_battery, oem_info), 1},
377 };
378 
379 static struct acpi_offsets extended_info_offsets[] = {
380 	{offsetof(struct acpi_battery, revision), 0},
381 	{offsetof(struct acpi_battery, power_unit), 0},
382 	{offsetof(struct acpi_battery, design_capacity), 0},
383 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
384 	{offsetof(struct acpi_battery, technology), 0},
385 	{offsetof(struct acpi_battery, design_voltage), 0},
386 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
387 	{offsetof(struct acpi_battery, design_capacity_low), 0},
388 	{offsetof(struct acpi_battery, cycle_count), 0},
389 	{offsetof(struct acpi_battery, measurement_accuracy), 0},
390 	{offsetof(struct acpi_battery, max_sampling_time), 0},
391 	{offsetof(struct acpi_battery, min_sampling_time), 0},
392 	{offsetof(struct acpi_battery, max_averaging_interval), 0},
393 	{offsetof(struct acpi_battery, min_averaging_interval), 0},
394 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
395 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
396 	{offsetof(struct acpi_battery, model_number), 1},
397 	{offsetof(struct acpi_battery, serial_number), 1},
398 	{offsetof(struct acpi_battery, type), 1},
399 	{offsetof(struct acpi_battery, oem_info), 1},
400 };
401 
402 static int extract_package(struct acpi_battery *battery,
403 			   union acpi_object *package,
404 			   struct acpi_offsets *offsets, int num)
405 {
406 	int i;
407 	union acpi_object *element;
408 	if (package->type != ACPI_TYPE_PACKAGE)
409 		return -EFAULT;
410 	for (i = 0; i < num; ++i) {
411 		if (package->package.count <= i)
412 			return -EFAULT;
413 		element = &package->package.elements[i];
414 		if (offsets[i].mode) {
415 			u8 *ptr = (u8 *)battery + offsets[i].offset;
416 			if (element->type == ACPI_TYPE_STRING ||
417 			    element->type == ACPI_TYPE_BUFFER)
418 				strncpy(ptr, element->string.pointer, 32);
419 			else if (element->type == ACPI_TYPE_INTEGER) {
420 				strncpy(ptr, (u8 *)&element->integer.value,
421 					sizeof(u64));
422 				ptr[sizeof(u64)] = 0;
423 			} else
424 				*ptr = 0; /* don't have value */
425 		} else {
426 			int *x = (int *)((u8 *)battery + offsets[i].offset);
427 			*x = (element->type == ACPI_TYPE_INTEGER) ?
428 				element->integer.value : -1;
429 		}
430 	}
431 	return 0;
432 }
433 
434 static int acpi_battery_get_status(struct acpi_battery *battery)
435 {
436 	if (acpi_bus_get_status(battery->device)) {
437 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
438 		return -ENODEV;
439 	}
440 	return 0;
441 }
442 
443 static int acpi_battery_get_info(struct acpi_battery *battery)
444 {
445 	int result = -EFAULT;
446 	acpi_status status = 0;
447 	char *name = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags) ?
448 			"_BIX" : "_BIF";
449 
450 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
451 
452 	if (!acpi_battery_present(battery))
453 		return 0;
454 	mutex_lock(&battery->lock);
455 	status = acpi_evaluate_object(battery->device->handle, name,
456 						NULL, &buffer);
457 	mutex_unlock(&battery->lock);
458 
459 	if (ACPI_FAILURE(status)) {
460 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating %s", name));
461 		return -ENODEV;
462 	}
463 
464 	if (battery_bix_broken_package)
465 		result = extract_package(battery, buffer.pointer,
466 				extended_info_offsets + 1,
467 				ARRAY_SIZE(extended_info_offsets) - 1);
468 	else if (test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags))
469 		result = extract_package(battery, buffer.pointer,
470 				extended_info_offsets,
471 				ARRAY_SIZE(extended_info_offsets));
472 	else
473 		result = extract_package(battery, buffer.pointer,
474 				info_offsets, ARRAY_SIZE(info_offsets));
475 	kfree(buffer.pointer);
476 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
477 		battery->full_charge_capacity = battery->design_capacity;
478 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
479 	    battery->power_unit && battery->design_voltage) {
480 		battery->design_capacity = battery->design_capacity *
481 		    10000 / battery->design_voltage;
482 		battery->full_charge_capacity = battery->full_charge_capacity *
483 		    10000 / battery->design_voltage;
484 		battery->design_capacity_warning =
485 		    battery->design_capacity_warning *
486 		    10000 / battery->design_voltage;
487 		/* Curiously, design_capacity_low, unlike the rest of them,
488 		   is correct.  */
489 		/* capacity_granularity_* equal 1 on the systems tested, so
490 		   it's impossible to tell if they would need an adjustment
491 		   or not if their values were higher.  */
492 	}
493 	return result;
494 }
495 
496 static int acpi_battery_get_state(struct acpi_battery *battery)
497 {
498 	int result = 0;
499 	acpi_status status = 0;
500 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
501 
502 	if (!acpi_battery_present(battery))
503 		return 0;
504 
505 	if (battery->update_time &&
506 	    time_before(jiffies, battery->update_time +
507 			msecs_to_jiffies(cache_time)))
508 		return 0;
509 
510 	mutex_lock(&battery->lock);
511 	status = acpi_evaluate_object(battery->device->handle, "_BST",
512 				      NULL, &buffer);
513 	mutex_unlock(&battery->lock);
514 
515 	if (ACPI_FAILURE(status)) {
516 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
517 		return -ENODEV;
518 	}
519 
520 	result = extract_package(battery, buffer.pointer,
521 				 state_offsets, ARRAY_SIZE(state_offsets));
522 	battery->update_time = jiffies;
523 	kfree(buffer.pointer);
524 
525 	/* For buggy DSDTs that report negative 16-bit values for either
526 	 * charging or discharging current and/or report 0 as 65536
527 	 * due to bad math.
528 	 */
529 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
530 		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
531 		(s16)(battery->rate_now) < 0) {
532 		battery->rate_now = abs((s16)battery->rate_now);
533 		printk_once(KERN_WARNING FW_BUG "battery: (dis)charge rate"
534 			" invalid.\n");
535 	}
536 
537 	/*
538 	 * When fully charged, some batteries wrongly report
539 	 * capacity_now = design_capacity instead of = full_charge_capacity
540 	 */
541 	if (battery->capacity_now > battery->full_charge_capacity
542 	    && battery->full_charge_capacity != ACPI_BATTERY_VALUE_UNKNOWN) {
543 		if (battery->capacity_now != battery->design_capacity)
544 			printk_once(KERN_WARNING FW_BUG
545 				"battery: reported current charge level (%d) "
546 				"is higher than reported maximum charge level (%d).\n",
547 				battery->capacity_now, battery->full_charge_capacity);
548 		battery->capacity_now = battery->full_charge_capacity;
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 	int result;
626 
627 	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
628 		battery->bat.properties = charge_battery_props;
629 		battery->bat.num_properties =
630 			ARRAY_SIZE(charge_battery_props);
631 	} else {
632 		battery->bat.properties = energy_battery_props;
633 		battery->bat.num_properties =
634 			ARRAY_SIZE(energy_battery_props);
635 	}
636 
637 	battery->bat.name = acpi_device_bid(battery->device);
638 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
639 	battery->bat.get_property = acpi_battery_get_property;
640 
641 	result = power_supply_register_no_ws(&battery->device->dev, &battery->bat);
642 
643 	if (result)
644 		return result;
645 	return device_create_file(battery->bat.dev, &alarm_attr);
646 }
647 
648 static void sysfs_remove_battery(struct acpi_battery *battery)
649 {
650 	mutex_lock(&battery->sysfs_lock);
651 	if (!battery->bat.dev) {
652 		mutex_unlock(&battery->sysfs_lock);
653 		return;
654 	}
655 
656 	device_remove_file(battery->bat.dev, &alarm_attr);
657 	power_supply_unregister(&battery->bat);
658 	battery->bat.dev = NULL;
659 	mutex_unlock(&battery->sysfs_lock);
660 }
661 
662 static void find_battery(const struct dmi_header *dm, void *private)
663 {
664 	struct acpi_battery *battery = (struct acpi_battery *)private;
665 	/* Note: the hardcoded offsets below have been extracted from
666 	   the source code of dmidecode.  */
667 	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
668 		const u8 *dmi_data = (const u8 *)(dm + 1);
669 		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
670 		if (dm->length >= 18)
671 			dmi_capacity *= dmi_data[17];
672 		if (battery->design_capacity * battery->design_voltage / 1000
673 		    != dmi_capacity &&
674 		    battery->design_capacity * 10 == dmi_capacity)
675 			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
676 				&battery->flags);
677 	}
678 }
679 
680 /*
681  * According to the ACPI spec, some kinds of primary batteries can
682  * report percentage battery remaining capacity directly to OS.
683  * In this case, it reports the Last Full Charged Capacity == 100
684  * and BatteryPresentRate == 0xFFFFFFFF.
685  *
686  * Now we found some battery reports percentage remaining capacity
687  * even if it's rechargeable.
688  * https://bugzilla.kernel.org/show_bug.cgi?id=15979
689  *
690  * Handle this correctly so that they won't break userspace.
691  */
692 static void acpi_battery_quirks(struct acpi_battery *battery)
693 {
694 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
695 		return;
696 
697 	if (battery->full_charge_capacity == 100 &&
698 		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
699 		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
700 		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
701 		battery->full_charge_capacity = battery->design_capacity;
702 		battery->capacity_now = (battery->capacity_now *
703 				battery->full_charge_capacity) / 100;
704 	}
705 
706 	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
707 		return;
708 
709 	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
710 		const char *s;
711 		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
712 		if (s && !strnicmp(s, "ThinkPad", 8)) {
713 			dmi_walk(find_battery, battery);
714 			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
715 				     &battery->flags) &&
716 			    battery->design_voltage) {
717 				battery->design_capacity =
718 				    battery->design_capacity *
719 				    10000 / battery->design_voltage;
720 				battery->full_charge_capacity =
721 				    battery->full_charge_capacity *
722 				    10000 / battery->design_voltage;
723 				battery->design_capacity_warning =
724 				    battery->design_capacity_warning *
725 				    10000 / battery->design_voltage;
726 				battery->capacity_now = battery->capacity_now *
727 				    10000 / battery->design_voltage;
728 			}
729 		}
730 	}
731 }
732 
733 static int acpi_battery_update(struct acpi_battery *battery, bool resume)
734 {
735 	int result, old_present = acpi_battery_present(battery);
736 	result = acpi_battery_get_status(battery);
737 	if (result)
738 		return result;
739 	if (!acpi_battery_present(battery)) {
740 		sysfs_remove_battery(battery);
741 		battery->update_time = 0;
742 		return 0;
743 	}
744 
745 	if (resume)
746 		return 0;
747 
748 	if (!battery->update_time ||
749 	    old_present != acpi_battery_present(battery)) {
750 		result = acpi_battery_get_info(battery);
751 		if (result)
752 			return result;
753 		acpi_battery_init_alarm(battery);
754 	}
755 	if (!battery->bat.dev) {
756 		result = sysfs_add_battery(battery);
757 		if (result)
758 			return result;
759 	}
760 	result = acpi_battery_get_state(battery);
761 	if (result)
762 		return result;
763 	acpi_battery_quirks(battery);
764 
765 	/*
766 	 * Wakeup the system if battery is critical low
767 	 * or lower than the alarm level
768 	 */
769 	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
770 	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
771             (battery->capacity_now <= battery->alarm)))
772 		pm_wakeup_event(&battery->device->dev, 0);
773 
774 	return result;
775 }
776 
777 static void acpi_battery_refresh(struct acpi_battery *battery)
778 {
779 	int power_unit;
780 
781 	if (!battery->bat.dev)
782 		return;
783 
784 	power_unit = battery->power_unit;
785 
786 	acpi_battery_get_info(battery);
787 
788 	if (power_unit == battery->power_unit)
789 		return;
790 
791 	/* The battery has changed its reporting units. */
792 	sysfs_remove_battery(battery);
793 	sysfs_add_battery(battery);
794 }
795 
796 /* --------------------------------------------------------------------------
797                               FS Interface (/proc)
798    -------------------------------------------------------------------------- */
799 
800 #ifdef CONFIG_ACPI_PROCFS_POWER
801 static struct proc_dir_entry *acpi_battery_dir;
802 
803 static int acpi_battery_print_info(struct seq_file *seq, int result)
804 {
805 	struct acpi_battery *battery = seq->private;
806 
807 	if (result)
808 		goto end;
809 
810 	seq_printf(seq, "present:                 %s\n",
811 		   acpi_battery_present(battery) ? "yes" : "no");
812 	if (!acpi_battery_present(battery))
813 		goto end;
814 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
815 		seq_printf(seq, "design capacity:         unknown\n");
816 	else
817 		seq_printf(seq, "design capacity:         %d %sh\n",
818 			   battery->design_capacity,
819 			   acpi_battery_units(battery));
820 
821 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
822 		seq_printf(seq, "last full capacity:      unknown\n");
823 	else
824 		seq_printf(seq, "last full capacity:      %d %sh\n",
825 			   battery->full_charge_capacity,
826 			   acpi_battery_units(battery));
827 
828 	seq_printf(seq, "battery technology:      %srechargeable\n",
829 		   (!battery->technology)?"non-":"");
830 
831 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
832 		seq_printf(seq, "design voltage:          unknown\n");
833 	else
834 		seq_printf(seq, "design voltage:          %d mV\n",
835 			   battery->design_voltage);
836 	seq_printf(seq, "design capacity warning: %d %sh\n",
837 		   battery->design_capacity_warning,
838 		   acpi_battery_units(battery));
839 	seq_printf(seq, "design capacity low:     %d %sh\n",
840 		   battery->design_capacity_low,
841 		   acpi_battery_units(battery));
842 	seq_printf(seq, "cycle count:		  %i\n", battery->cycle_count);
843 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
844 		   battery->capacity_granularity_1,
845 		   acpi_battery_units(battery));
846 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
847 		   battery->capacity_granularity_2,
848 		   acpi_battery_units(battery));
849 	seq_printf(seq, "model number:            %s\n", battery->model_number);
850 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
851 	seq_printf(seq, "battery type:            %s\n", battery->type);
852 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
853       end:
854 	if (result)
855 		seq_printf(seq, "ERROR: Unable to read battery info\n");
856 	return result;
857 }
858 
859 static int acpi_battery_print_state(struct seq_file *seq, int result)
860 {
861 	struct acpi_battery *battery = seq->private;
862 
863 	if (result)
864 		goto end;
865 
866 	seq_printf(seq, "present:                 %s\n",
867 		   acpi_battery_present(battery) ? "yes" : "no");
868 	if (!acpi_battery_present(battery))
869 		goto end;
870 
871 	seq_printf(seq, "capacity state:          %s\n",
872 			(battery->state & 0x04) ? "critical" : "ok");
873 	if ((battery->state & 0x01) && (battery->state & 0x02))
874 		seq_printf(seq,
875 			   "charging state:          charging/discharging\n");
876 	else if (battery->state & 0x01)
877 		seq_printf(seq, "charging state:          discharging\n");
878 	else if (battery->state & 0x02)
879 		seq_printf(seq, "charging state:          charging\n");
880 	else
881 		seq_printf(seq, "charging state:          charged\n");
882 
883 	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
884 		seq_printf(seq, "present rate:            unknown\n");
885 	else
886 		seq_printf(seq, "present rate:            %d %s\n",
887 			   battery->rate_now, acpi_battery_units(battery));
888 
889 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
890 		seq_printf(seq, "remaining capacity:      unknown\n");
891 	else
892 		seq_printf(seq, "remaining capacity:      %d %sh\n",
893 			   battery->capacity_now, acpi_battery_units(battery));
894 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
895 		seq_printf(seq, "present voltage:         unknown\n");
896 	else
897 		seq_printf(seq, "present voltage:         %d mV\n",
898 			   battery->voltage_now);
899       end:
900 	if (result)
901 		seq_printf(seq, "ERROR: Unable to read battery state\n");
902 
903 	return result;
904 }
905 
906 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
907 {
908 	struct acpi_battery *battery = seq->private;
909 
910 	if (result)
911 		goto end;
912 
913 	if (!acpi_battery_present(battery)) {
914 		seq_printf(seq, "present:                 no\n");
915 		goto end;
916 	}
917 	seq_printf(seq, "alarm:                   ");
918 	if (!battery->alarm)
919 		seq_printf(seq, "unsupported\n");
920 	else
921 		seq_printf(seq, "%u %sh\n", battery->alarm,
922 				acpi_battery_units(battery));
923       end:
924 	if (result)
925 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
926 	return result;
927 }
928 
929 static ssize_t acpi_battery_write_alarm(struct file *file,
930 					const char __user * buffer,
931 					size_t count, loff_t * ppos)
932 {
933 	int result = 0;
934 	char alarm_string[12] = { '\0' };
935 	struct seq_file *m = file->private_data;
936 	struct acpi_battery *battery = m->private;
937 
938 	if (!battery || (count > sizeof(alarm_string) - 1))
939 		return -EINVAL;
940 	if (!acpi_battery_present(battery)) {
941 		result = -ENODEV;
942 		goto end;
943 	}
944 	if (copy_from_user(alarm_string, buffer, count)) {
945 		result = -EFAULT;
946 		goto end;
947 	}
948 	alarm_string[count] = '\0';
949 	if (kstrtoint(alarm_string, 0, &battery->alarm)) {
950 		result = -EINVAL;
951 		goto end;
952 	}
953 	result = acpi_battery_set_alarm(battery);
954       end:
955 	if (!result)
956 		return count;
957 	return result;
958 }
959 
960 typedef int(*print_func)(struct seq_file *seq, int result);
961 
962 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
963 	acpi_battery_print_info,
964 	acpi_battery_print_state,
965 	acpi_battery_print_alarm,
966 };
967 
968 static int acpi_battery_read(int fid, struct seq_file *seq)
969 {
970 	struct acpi_battery *battery = seq->private;
971 	int result = acpi_battery_update(battery, false);
972 	return acpi_print_funcs[fid](seq, result);
973 }
974 
975 #define DECLARE_FILE_FUNCTIONS(_name) \
976 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
977 { \
978 	return acpi_battery_read(_name##_tag, seq); \
979 } \
980 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
981 { \
982 	return single_open(file, acpi_battery_read_##_name, PDE_DATA(inode)); \
983 }
984 
985 DECLARE_FILE_FUNCTIONS(info);
986 DECLARE_FILE_FUNCTIONS(state);
987 DECLARE_FILE_FUNCTIONS(alarm);
988 
989 #undef DECLARE_FILE_FUNCTIONS
990 
991 #define FILE_DESCRIPTION_RO(_name) \
992 	{ \
993 	.name = __stringify(_name), \
994 	.mode = S_IRUGO, \
995 	.ops = { \
996 		.open = acpi_battery_##_name##_open_fs, \
997 		.read = seq_read, \
998 		.llseek = seq_lseek, \
999 		.release = single_release, \
1000 		.owner = THIS_MODULE, \
1001 		}, \
1002 	}
1003 
1004 #define FILE_DESCRIPTION_RW(_name) \
1005 	{ \
1006 	.name = __stringify(_name), \
1007 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
1008 	.ops = { \
1009 		.open = acpi_battery_##_name##_open_fs, \
1010 		.read = seq_read, \
1011 		.llseek = seq_lseek, \
1012 		.write = acpi_battery_write_##_name, \
1013 		.release = single_release, \
1014 		.owner = THIS_MODULE, \
1015 		}, \
1016 	}
1017 
1018 static const struct battery_file {
1019 	struct file_operations ops;
1020 	umode_t mode;
1021 	const char *name;
1022 } acpi_battery_file[] = {
1023 	FILE_DESCRIPTION_RO(info),
1024 	FILE_DESCRIPTION_RO(state),
1025 	FILE_DESCRIPTION_RW(alarm),
1026 };
1027 
1028 #undef FILE_DESCRIPTION_RO
1029 #undef FILE_DESCRIPTION_RW
1030 
1031 static int acpi_battery_add_fs(struct acpi_device *device)
1032 {
1033 	struct proc_dir_entry *entry = NULL;
1034 	int i;
1035 
1036 	printk(KERN_WARNING PREFIX "Deprecated procfs I/F for battery is loaded,"
1037 			" please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
1038 	if (!acpi_device_dir(device)) {
1039 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
1040 						     acpi_battery_dir);
1041 		if (!acpi_device_dir(device))
1042 			return -ENODEV;
1043 	}
1044 
1045 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
1046 		entry = proc_create_data(acpi_battery_file[i].name,
1047 					 acpi_battery_file[i].mode,
1048 					 acpi_device_dir(device),
1049 					 &acpi_battery_file[i].ops,
1050 					 acpi_driver_data(device));
1051 		if (!entry)
1052 			return -ENODEV;
1053 	}
1054 	return 0;
1055 }
1056 
1057 static void acpi_battery_remove_fs(struct acpi_device *device)
1058 {
1059 	int i;
1060 	if (!acpi_device_dir(device))
1061 		return;
1062 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
1063 		remove_proc_entry(acpi_battery_file[i].name,
1064 				  acpi_device_dir(device));
1065 
1066 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
1067 	acpi_device_dir(device) = NULL;
1068 }
1069 
1070 #endif
1071 
1072 /* --------------------------------------------------------------------------
1073                                  Driver Interface
1074    -------------------------------------------------------------------------- */
1075 
1076 static void acpi_battery_notify(struct acpi_device *device, u32 event)
1077 {
1078 	struct acpi_battery *battery = acpi_driver_data(device);
1079 	struct device *old;
1080 
1081 	if (!battery)
1082 		return;
1083 	old = battery->bat.dev;
1084 	/*
1085 	* On Acer Aspire V5-573G notifications are sometimes triggered too
1086 	* early. For example, when AC is unplugged and notification is
1087 	* triggered, battery state is still reported as "Full", and changes to
1088 	* "Discharging" only after short delay, without any notification.
1089 	*/
1090 	if (battery_notification_delay_ms > 0)
1091 		msleep(battery_notification_delay_ms);
1092 	if (event == ACPI_BATTERY_NOTIFY_INFO)
1093 		acpi_battery_refresh(battery);
1094 	acpi_battery_update(battery, false);
1095 	acpi_bus_generate_netlink_event(device->pnp.device_class,
1096 					dev_name(&device->dev), event,
1097 					acpi_battery_present(battery));
1098 	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
1099 	/* acpi_battery_update could remove power_supply object */
1100 	if (old && battery->bat.dev)
1101 		power_supply_changed(&battery->bat);
1102 }
1103 
1104 static int battery_notify(struct notifier_block *nb,
1105 			       unsigned long mode, void *_unused)
1106 {
1107 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
1108 						    pm_nb);
1109 	int result;
1110 
1111 	switch (mode) {
1112 	case PM_POST_HIBERNATION:
1113 	case PM_POST_SUSPEND:
1114 		if (!acpi_battery_present(battery))
1115 			return 0;
1116 
1117 		if (!battery->bat.dev) {
1118 			result = acpi_battery_get_info(battery);
1119 			if (result)
1120 				return result;
1121 
1122 			result = sysfs_add_battery(battery);
1123 			if (result)
1124 				return result;
1125 		} else
1126 			acpi_battery_refresh(battery);
1127 
1128 		acpi_battery_init_alarm(battery);
1129 		acpi_battery_get_state(battery);
1130 		break;
1131 	}
1132 
1133 	return 0;
1134 }
1135 
1136 static int battery_bix_broken_package_quirk(const struct dmi_system_id *d)
1137 {
1138 	battery_bix_broken_package = 1;
1139 	return 0;
1140 }
1141 
1142 static int battery_notification_delay_quirk(const struct dmi_system_id *d)
1143 {
1144 	battery_notification_delay_ms = 1000;
1145 	return 0;
1146 }
1147 
1148 static struct dmi_system_id bat_dmi_table[] = {
1149 	{
1150 		.callback = battery_bix_broken_package_quirk,
1151 		.ident = "NEC LZ750/LS",
1152 		.matches = {
1153 			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1154 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
1155 		},
1156 	},
1157 	{
1158 		.callback = battery_notification_delay_quirk,
1159 		.ident = "Acer Aspire V5-573G",
1160 		.matches = {
1161 			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1162 			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
1163 		},
1164 	},
1165 	{},
1166 };
1167 
1168 /*
1169  * Some machines'(E,G Lenovo Z480) ECs are not stable
1170  * during boot up and this causes battery driver fails to be
1171  * probed due to failure of getting battery information
1172  * from EC sometimes. After several retries, the operation
1173  * may work. So add retry code here and 20ms sleep between
1174  * every retries.
1175  */
1176 static int acpi_battery_update_retry(struct acpi_battery *battery)
1177 {
1178 	int retry, ret;
1179 
1180 	for (retry = 5; retry; retry--) {
1181 		ret = acpi_battery_update(battery, false);
1182 		if (!ret)
1183 			break;
1184 
1185 		msleep(20);
1186 	}
1187 	return ret;
1188 }
1189 
1190 static int acpi_battery_add(struct acpi_device *device)
1191 {
1192 	int result = 0;
1193 	struct acpi_battery *battery = NULL;
1194 
1195 	if (!device)
1196 		return -EINVAL;
1197 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
1198 	if (!battery)
1199 		return -ENOMEM;
1200 	battery->device = device;
1201 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
1202 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
1203 	device->driver_data = battery;
1204 	mutex_init(&battery->lock);
1205 	mutex_init(&battery->sysfs_lock);
1206 	if (acpi_has_method(battery->device->handle, "_BIX"))
1207 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
1208 
1209 	result = acpi_battery_update_retry(battery);
1210 	if (result)
1211 		goto fail;
1212 
1213 #ifdef CONFIG_ACPI_PROCFS_POWER
1214 	result = acpi_battery_add_fs(device);
1215 #endif
1216 	if (result) {
1217 #ifdef CONFIG_ACPI_PROCFS_POWER
1218 		acpi_battery_remove_fs(device);
1219 #endif
1220 		goto fail;
1221 	}
1222 
1223 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
1224 		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
1225 		device->status.battery_present ? "present" : "absent");
1226 
1227 	battery->pm_nb.notifier_call = battery_notify;
1228 	register_pm_notifier(&battery->pm_nb);
1229 
1230 	device_init_wakeup(&device->dev, 1);
1231 
1232 	return result;
1233 
1234 fail:
1235 	sysfs_remove_battery(battery);
1236 	mutex_destroy(&battery->lock);
1237 	mutex_destroy(&battery->sysfs_lock);
1238 	kfree(battery);
1239 	return result;
1240 }
1241 
1242 static int acpi_battery_remove(struct acpi_device *device)
1243 {
1244 	struct acpi_battery *battery = NULL;
1245 
1246 	if (!device || !acpi_driver_data(device))
1247 		return -EINVAL;
1248 	device_init_wakeup(&device->dev, 0);
1249 	battery = acpi_driver_data(device);
1250 	unregister_pm_notifier(&battery->pm_nb);
1251 #ifdef CONFIG_ACPI_PROCFS_POWER
1252 	acpi_battery_remove_fs(device);
1253 #endif
1254 	sysfs_remove_battery(battery);
1255 	mutex_destroy(&battery->lock);
1256 	mutex_destroy(&battery->sysfs_lock);
1257 	kfree(battery);
1258 	return 0;
1259 }
1260 
1261 #ifdef CONFIG_PM_SLEEP
1262 /* this is needed to learn about changes made in suspended state */
1263 static int acpi_battery_resume(struct device *dev)
1264 {
1265 	struct acpi_battery *battery;
1266 
1267 	if (!dev)
1268 		return -EINVAL;
1269 
1270 	battery = acpi_driver_data(to_acpi_device(dev));
1271 	if (!battery)
1272 		return -EINVAL;
1273 
1274 	battery->update_time = 0;
1275 	acpi_battery_update(battery, true);
1276 	return 0;
1277 }
1278 #else
1279 #define acpi_battery_resume NULL
1280 #endif
1281 
1282 static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
1283 
1284 static struct acpi_driver acpi_battery_driver = {
1285 	.name = "battery",
1286 	.class = ACPI_BATTERY_CLASS,
1287 	.ids = battery_device_ids,
1288 	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
1289 	.ops = {
1290 		.add = acpi_battery_add,
1291 		.remove = acpi_battery_remove,
1292 		.notify = acpi_battery_notify,
1293 		},
1294 	.drv.pm = &acpi_battery_pm,
1295 };
1296 
1297 static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
1298 {
1299 	if (acpi_disabled)
1300 		return;
1301 
1302 	dmi_check_system(bat_dmi_table);
1303 
1304 #ifdef CONFIG_ACPI_PROCFS_POWER
1305 	acpi_battery_dir = acpi_lock_battery_dir();
1306 	if (!acpi_battery_dir)
1307 		return;
1308 #endif
1309 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
1310 #ifdef CONFIG_ACPI_PROCFS_POWER
1311 		acpi_unlock_battery_dir(acpi_battery_dir);
1312 #endif
1313 		return;
1314 	}
1315 	return;
1316 }
1317 
1318 static int __init acpi_battery_init(void)
1319 {
1320 	async_schedule(acpi_battery_init_async, NULL);
1321 	return 0;
1322 }
1323 
1324 static void __exit acpi_battery_exit(void)
1325 {
1326 	acpi_bus_unregister_driver(&acpi_battery_driver);
1327 #ifdef CONFIG_ACPI_PROCFS_POWER
1328 	acpi_unlock_battery_dir(acpi_battery_dir);
1329 #endif
1330 }
1331 
1332 module_init(acpi_battery_init);
1333 module_exit(acpi_battery_exit);
1334