summaryrefslogtreecommitdiff
path: root/drivers/power/ds2760_battery.c
blob: e82dff0bbb2092a0afc7feb92c8c19d420bb9b6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
/*
 * Driver for batteries with DS2760 chips inside.
 *
 * Copyright © 2007 Anton Vorontsov
 *	       2004-2007 Matt Reimer
 *	       2004 Szabolcs Gyurko
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 * Author:  Anton Vorontsov <cbou@mail.ru>
 *	    February 2007
 *
 *	    Matt Reimer <mreimer@vpop.net>
 *	    April 2004, 2005, 2007
 *
 *	    Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
 *	    September 2004
 */

#include <linux/module.h>
#include <linux/param.h>
#include <linux/jiffies.h>
#include <linux/workqueue.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>

#include "../w1/w1.h"
#include "../w1/slaves/w1_ds2760.h"

struct ds2760_device_info {
	struct device *dev;

	/* DS2760 data, valid after calling ds2760_battery_read_status() */
	unsigned long update_time;	/* jiffies when data read */
	char raw[DS2760_DATA_SIZE];	/* raw DS2760 data */
	int voltage_raw;		/* units of 4.88 mV */
	int voltage_uV;			/* units of µV */
	int current_raw;		/* units of 0.625 mA */
	int current_uA;			/* units of µA */
	int accum_current_raw;		/* units of 0.25 mAh */
	int accum_current_uAh;		/* units of µAh */
	int temp_raw;			/* units of 0.125 °C */
	int temp_C;			/* units of 0.1 °C */
	int rated_capacity;		/* units of µAh */
	int rem_capacity;		/* percentage */
	int full_active_uAh;		/* units of µAh */
	int empty_uAh;			/* units of µAh */
	int life_sec;			/* units of seconds */
	int charge_status;		/* POWER_SUPPLY_STATUS_* */

	int full_counter;
	struct power_supply bat;
	struct device *w1_dev;
	struct workqueue_struct *monitor_wqueue;
	struct delayed_work monitor_work;
	struct delayed_work set_charged_work;
};

static unsigned int cache_time = 1000;
module_param(cache_time, uint, 0644);
MODULE_PARM_DESC(cache_time, "cache time in milliseconds");

static bool pmod_enabled;
module_param(pmod_enabled, bool, 0644);
MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");

static unsigned int rated_capacity;
module_param(rated_capacity, uint, 0644);
MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");

static unsigned int current_accum;
module_param(current_accum, uint, 0644);
MODULE_PARM_DESC(current_accum, "current accumulator value");

/* Some batteries have their rated capacity stored a N * 10 mAh, while
 * others use an index into this table. */
static int rated_capacities[] = {
	0,
	920,	/* Samsung */
	920,	/* BYD */
	920,	/* Lishen */
	920,	/* NEC */
	1440,	/* Samsung */
	1440,	/* BYD */
#ifdef CONFIG_MACH_H4700
	1800,	/* HP iPAQ hx4700 3.7V 1800mAh (359113-001) */
#else
	1440,	/* Lishen */
#endif
	1440,	/* NEC */
	2880,	/* Samsung */
	2880,	/* BYD */
	2880,	/* Lishen */
	2880,	/* NEC */
#ifdef CONFIG_MACH_H4700
	0,
	3600,	/* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
#endif
};

/* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
 * temp is in Celsius */
static int battery_interpolate(int array[], int temp)
{
	int index, dt;

	if (temp <= 0)
		return array[0];
	if (temp >= 40)
		return array[4];

	index = temp / 10;
	dt    = temp % 10;

	return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
}

static int ds2760_battery_read_status(struct ds2760_device_info *di)
{
	int ret, i, start, count, scale[5];

	if (di->update_time && time_before(jiffies, di->update_time +
					   msecs_to_jiffies(cache_time)))
		return 0;

	/* The first time we read the entire contents of SRAM/EEPROM,
	 * but after that we just read the interesting bits that change. */
	if (di->update_time == 0) {
		start = 0;
		count = DS2760_DATA_SIZE;
	} else {
		start = DS2760_VOLTAGE_MSB;
		count = DS2760_TEMP_LSB - start + 1;
	}

	ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
	if (ret != count) {
		dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
			 di->w1_dev);
		return 1;
	}

	di->update_time = jiffies;

	/* DS2760 reports voltage in units of 4.88mV, but the battery class
	 * reports in units of uV, so convert by multiplying by 4880. */
	di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
			  (di->raw[DS2760_VOLTAGE_LSB] >> 5);
	di->voltage_uV = di->voltage_raw * 4880;

	/* DS2760 reports current in signed units of 0.625mA, but the battery
	 * class reports in units of µA, so convert by multiplying by 625. */
	di->current_raw =
	    (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
			  (di->raw[DS2760_CURRENT_LSB] >> 3);
	di->current_uA = di->current_raw * 625;

	/* DS2760 reports accumulated current in signed units of 0.25mAh. */
	di->accum_current_raw =
	    (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
			   di->raw[DS2760_CURRENT_ACCUM_LSB];
	di->accum_current_uAh = di->accum_current_raw * 250;

	/* DS2760 reports temperature in signed units of 0.125°C, but the
	 * battery class reports in units of 1/10 °C, so we convert by
	 * multiplying by .125 * 10 = 1.25. */
	di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
				     (di->raw[DS2760_TEMP_LSB] >> 5);
	di->temp_C = di->temp_raw + (di->temp_raw / 4);

	/* At least some battery monitors (e.g. HP iPAQ) store the battery's
	 * maximum rated capacity. */
	if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
		di->rated_capacity = rated_capacities[
			(unsigned int)di->raw[DS2760_RATED_CAPACITY]];
	else
		di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;

	di->rated_capacity *= 1000; /* convert to µAh */

	/* Calculate the full level at the present temperature. */
	di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
			      di->raw[DS2760_ACTIVE_FULL + 1];

	/* If the full_active_uAh value is not given, fall back to the rated
	 * capacity. This is likely to happen when chips are not part of the
	 * battery pack and is therefore not bootstrapped. */
	if (di->full_active_uAh == 0)
		di->full_active_uAh = di->rated_capacity / 1000L;

	scale[0] = di->full_active_uAh;
	for (i = 1; i < 5; i++)
		scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];

	di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
	di->full_active_uAh *= 1000; /* convert to µAh */

	/* Calculate the empty level at the present temperature. */
	scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
	for (i = 3; i >= 0; i--)
		scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];

	di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
	di->empty_uAh *= 1000; /* convert to µAh */

	if (di->full_active_uAh == di->empty_uAh)
		di->rem_capacity = 0;
	else
		/* From Maxim Application Note 131: remaining capacity =
		 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
		di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
				    (di->full_active_uAh - di->empty_uAh);

	if (di->rem_capacity < 0)
		di->rem_capacity = 0;
	if (di->rem_capacity > 100)
		di->rem_capacity = 100;

	if (di->current_uA < -100L)
		di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
					/ (di->current_uA / 100L);
	else
		di->life_sec = 0;

	return 0;
}

static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
					     unsigned int acr_val)
{
	unsigned char acr[2];

	/* acr is in units of 0.25 mAh */
	acr_val *= 4L;
	acr_val /= 1000;

	acr[0] = acr_val >> 8;
	acr[1] = acr_val & 0xff;

	if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
		dev_warn(di->dev, "ACR write failed\n");
}

static void ds2760_battery_update_status(struct ds2760_device_info *di)
{
	int old_charge_status = di->charge_status;

	ds2760_battery_read_status(di);

	if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
		di->full_counter = 0;

	if (power_supply_am_i_supplied(&di->bat)) {
		if (di->current_uA > 10000) {
			di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
			di->full_counter = 0;
		} else if (di->current_uA < -5000) {
			if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
				dev_notice(di->dev, "not enough power to "
					   "charge\n");
			di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
			di->full_counter = 0;
		} else if (di->current_uA < 10000 &&
			    di->charge_status != POWER_SUPPLY_STATUS_FULL) {

			/* Don't consider the battery to be full unless
			 * we've seen the current < 10 mA at least two
			 * consecutive times. */

			di->full_counter++;

			if (di->full_counter < 2) {
				di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
			} else {
				di->charge_status = POWER_SUPPLY_STATUS_FULL;
				ds2760_battery_set_current_accum(di,
						di->full_active_uAh);
			}
		}
	} else {
		di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
		di->full_counter = 0;
	}

	if (di->charge_status != old_charge_status)
		power_supply_changed(&di->bat);
}

static void ds2760_battery_write_status(struct ds2760_device_info *di,
					char status)
{
	if (status == di->raw[DS2760_STATUS_REG])
		return;

	w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
}

static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
						unsigned char rated_capacity)
{
	if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
		return;

	w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
}

static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
					     int active_full)
{
	unsigned char tmp[2] = {
		active_full >> 8,
		active_full & 0xff
	};

	if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
	    tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
		return;

	w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);

	/* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
	 * values won't be read back by ds2760_battery_read_status() */
	di->raw[DS2760_ACTIVE_FULL] = tmp[0];
	di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
}

static void ds2760_battery_work(struct work_struct *work)
{
	struct ds2760_device_info *di = container_of(work,
		struct ds2760_device_info, monitor_work.work);
	const int interval = HZ * 60;

	dev_dbg(di->dev, "%s\n", __func__);

	ds2760_battery_update_status(di);
	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
}

#define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
					      bat);

static void ds2760_battery_external_power_changed(struct power_supply *psy)
{
	struct ds2760_device_info *di = to_ds2760_device_info(psy);

	dev_dbg(di->dev, "%s\n", __func__);

	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
}


static void ds2760_battery_set_charged_work(struct work_struct *work)
{
	char bias;
	struct ds2760_device_info *di = container_of(work,
		struct ds2760_device_info, set_charged_work.work);

	dev_dbg(di->dev, "%s\n", __func__);

	ds2760_battery_read_status(di);

	/* When we get notified by external circuitry that the battery is
	 * considered fully charged now, we know that there is no current
	 * flow any more. However, the ds2760's internal current meter is
	 * too inaccurate to rely on - spec say something ~15% failure.
	 * Hence, we use the current offset bias register to compensate
	 * that error.
	 */

	if (!power_supply_am_i_supplied(&di->bat))
		return;

	bias = (signed char) di->current_raw +
		(signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];

	dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);

	w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);

	/* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
	 * value won't be read back by ds2760_battery_read_status() */
	di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
}

static void ds2760_battery_set_charged(struct power_supply *psy)
{
	struct ds2760_device_info *di = to_ds2760_device_info(psy);

	/* postpone the actual work by 20 secs. This is for debouncing GPIO
	 * signals and to let the current value settle. See AN4188. */
	mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
}

static int ds2760_battery_get_property(struct power_supply *psy,
				       enum power_supply_property psp,
				       union power_supply_propval *val)
{
	struct ds2760_device_info *di = to_ds2760_device_info(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
		val->intval = di->charge_status;
		return 0;
	default:
		break;
	}

	ds2760_battery_read_status(di);

	switch (psp) {
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		val->intval = di->voltage_uV;
		break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		val->intval = di->current_uA;
		break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
		val->intval = di->rated_capacity;
		break;
	case POWER_SUPPLY_PROP_CHARGE_FULL:
		val->intval = di->full_active_uAh;
		break;
	case POWER_SUPPLY_PROP_CHARGE_EMPTY:
		val->intval = di->empty_uAh;
		break;
	case POWER_SUPPLY_PROP_CHARGE_NOW:
		val->intval = di->accum_current_uAh;
		break;
	case POWER_SUPPLY_PROP_TEMP:
		val->intval = di->temp_C;
		break;
	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
		val->intval = di->life_sec;
		break;
	case POWER_SUPPLY_PROP_CAPACITY:
		val->intval = di->rem_capacity;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int ds2760_battery_set_property(struct power_supply *psy,
				       enum power_supply_property psp,
				       const union power_supply_propval *val)
{
	struct ds2760_device_info *di = to_ds2760_device_info(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGE_FULL:
		/* the interface counts in uAh, convert the value */
		ds2760_battery_write_active_full(di, val->intval / 1000L);
		break;

	case POWER_SUPPLY_PROP_CHARGE_NOW:
		/* ds2760_battery_set_current_accum() does the conversion */
		ds2760_battery_set_current_accum(di, val->intval);
		break;

	default:
		return -EPERM;
	}

	return 0;
}

static int ds2760_battery_property_is_writeable(struct power_supply *psy,
						enum power_supply_property psp)
{
	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGE_FULL:
	case POWER_SUPPLY_PROP_CHARGE_NOW:
		return 1;

	default:
		break;
	}

	return 0;
}

static enum power_supply_property ds2760_battery_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CHARGE_FULL,
	POWER_SUPPLY_PROP_CHARGE_EMPTY,
	POWER_SUPPLY_PROP_CHARGE_NOW,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
	POWER_SUPPLY_PROP_CAPACITY,
};

static int ds2760_battery_probe(struct platform_device *pdev)
{
	char status;
	int retval = 0;
	struct ds2760_device_info *di;

	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
	if (!di) {
		retval = -ENOMEM;
		goto di_alloc_failed;
	}

	platform_set_drvdata(pdev, di);

	di->dev			= &pdev->dev;
	di->w1_dev		= pdev->dev.parent;
	di->bat.name		= dev_name(&pdev->dev);
	di->bat.type		= POWER_SUPPLY_TYPE_BATTERY;
	di->bat.properties	= ds2760_battery_props;
	di->bat.num_properties	= ARRAY_SIZE(ds2760_battery_props);
	di->bat.get_property	= ds2760_battery_get_property;
	di->bat.set_property	= ds2760_battery_set_property;
	di->bat.property_is_writeable =
				  ds2760_battery_property_is_writeable;
	di->bat.set_charged	= ds2760_battery_set_charged;
	di->bat.external_power_changed =
				  ds2760_battery_external_power_changed;

	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;

	/* enable sleep mode feature */
	ds2760_battery_read_status(di);
	status = di->raw[DS2760_STATUS_REG];
	if (pmod_enabled)
		status |= DS2760_STATUS_PMOD;
	else
		status &= ~DS2760_STATUS_PMOD;

	ds2760_battery_write_status(di, status);

	/* set rated capacity from module param */
	if (rated_capacity)
		ds2760_battery_write_rated_capacity(di, rated_capacity);

	/* set current accumulator if given as parameter.
	 * this should only be done for bootstrapping the value */
	if (current_accum)
		ds2760_battery_set_current_accum(di, current_accum);

	retval = power_supply_register(&pdev->dev, &di->bat, NULL);
	if (retval) {
		dev_err(di->dev, "failed to register battery\n");
		goto batt_failed;
	}

	INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
	INIT_DELAYED_WORK(&di->set_charged_work,
			  ds2760_battery_set_charged_work);
	di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
	if (!di->monitor_wqueue) {
		retval = -ESRCH;
		goto workqueue_failed;
	}
	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);

	goto success;

workqueue_failed:
	power_supply_unregister(&di->bat);
batt_failed:
di_alloc_failed:
success:
	return retval;
}

static int ds2760_battery_remove(struct platform_device *pdev)
{
	struct ds2760_device_info *di = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&di->monitor_work);
	cancel_delayed_work_sync(&di->set_charged_work);
	destroy_workqueue(di->monitor_wqueue);
	power_supply_unregister(&di->bat);

	return 0;
}

#ifdef CONFIG_PM

static int ds2760_battery_suspend(struct platform_device *pdev,
				  pm_message_t state)
{
	struct ds2760_device_info *di = platform_get_drvdata(pdev);

	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;

	return 0;
}

static int ds2760_battery_resume(struct platform_device *pdev)
{
	struct ds2760_device_info *di = platform_get_drvdata(pdev);

	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
	power_supply_changed(&di->bat);

	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);

	return 0;
}

#else

#define ds2760_battery_suspend NULL
#define ds2760_battery_resume NULL

#endif /* CONFIG_PM */

MODULE_ALIAS("platform:ds2760-battery");

static struct platform_driver ds2760_battery_driver = {
	.driver = {
		.name = "ds2760-battery",
	},
	.probe	  = ds2760_battery_probe,
	.remove   = ds2760_battery_remove,
	.suspend  = ds2760_battery_suspend,
	.resume	  = ds2760_battery_resume,
};

module_platform_driver(ds2760_battery_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
	      "Matt Reimer <mreimer@vpop.net>, "
	      "Anton Vorontsov <cbou@mail.ru>");
MODULE_DESCRIPTION("ds2760 battery driver");