summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/power/power_supply_core.c
blob: 4bc0c7f459a52cfb0e0522ffa1d1a68ee6f6f4a9 (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
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
/*
 *  Universal power supply monitor class
 *
 *  Copyright © 2007  Anton Vorontsov <cbou@mail.ru>
 *  Copyright © 2004  Szabolcs Gyurko
 *  Copyright © 2003  Ian Molton <spyro@f2s.com>
 *
 *  Modified: 2004, Oct     Szabolcs Gyurko
 *
 *  You may use this code as per GPL version 2
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/thermal.h>
#include "power_supply.h"

/* exported for the APM Power driver, APM emulation */
struct class *power_supply_class;
EXPORT_SYMBOL_GPL(power_supply_class);

ATOMIC_NOTIFIER_HEAD(power_supply_notifier);
EXPORT_SYMBOL_GPL(power_supply_notifier);

static struct device_type power_supply_dev_type;

#define POWER_SUPPLY_DEFERRED_REGISTER_TIME	msecs_to_jiffies(10)

static bool __power_supply_is_supplied_by(struct power_supply *supplier,
					 struct power_supply *supply)
{
	int i;

	if (!supply->supplied_from && !supplier->supplied_to)
		return false;

	/* Support both supplied_to and supplied_from modes */
	if (supply->supplied_from) {
		if (!supplier->desc->name)
			return false;
		for (i = 0; i < supply->num_supplies; i++)
			if (!strcmp(supplier->desc->name, supply->supplied_from[i]))
				return true;
	} else {
		if (!supply->desc->name)
			return false;
		for (i = 0; i < supplier->num_supplicants; i++)
			if (!strcmp(supplier->supplied_to[i], supply->desc->name))
				return true;
	}

	return false;
}

static int __power_supply_changed_work(struct device *dev, void *data)
{
	struct power_supply *psy = data;
	struct power_supply *pst = dev_get_drvdata(dev);

	if (__power_supply_is_supplied_by(psy, pst)) {
		if (pst->desc->external_power_changed)
			pst->desc->external_power_changed(pst);
	}

	return 0;
}

static void power_supply_changed_work(struct work_struct *work)
{
	unsigned long flags;
	struct power_supply *psy = container_of(work, struct power_supply,
						changed_work);

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

	spin_lock_irqsave(&psy->changed_lock, flags);
	/*
	 * Check 'changed' here to avoid issues due to race between
	 * power_supply_changed() and this routine. In worst case
	 * power_supply_changed() can be called again just before we take above
	 * lock. During the first call of this routine we will mark 'changed' as
	 * false and it will stay false for the next call as well.
	 */
	if (likely(psy->changed)) {
		psy->changed = false;
		spin_unlock_irqrestore(&psy->changed_lock, flags);
		class_for_each_device(power_supply_class, NULL, psy,
				      __power_supply_changed_work);
		power_supply_update_leds(psy);
		atomic_notifier_call_chain(&power_supply_notifier,
				PSY_EVENT_PROP_CHANGED, psy);
		kobject_uevent(&psy->dev.kobj, KOBJ_CHANGE);
		spin_lock_irqsave(&psy->changed_lock, flags);
	}

	/*
	 * Hold the wakeup_source until all events are processed.
	 * power_supply_changed() might have called again and have set 'changed'
	 * to true.
	 */
	if (likely(!psy->changed))
		pm_relax(&psy->dev);
	spin_unlock_irqrestore(&psy->changed_lock, flags);
}

void power_supply_changed(struct power_supply *psy)
{
	unsigned long flags;

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

	spin_lock_irqsave(&psy->changed_lock, flags);
	psy->changed = true;
	pm_stay_awake(&psy->dev);
	spin_unlock_irqrestore(&psy->changed_lock, flags);
	schedule_work(&psy->changed_work);
}
EXPORT_SYMBOL_GPL(power_supply_changed);

/*
 * Notify that power supply was registered after parent finished the probing.
 *
 * Often power supply is registered from driver's probe function. However
 * calling power_supply_changed() directly from power_supply_register()
 * would lead to execution of get_property() function provided by the driver
 * too early - before the probe ends.
 *
 * Avoid that by waiting on parent's mutex.
 */
static void power_supply_deferred_register_work(struct work_struct *work)
{
	struct power_supply *psy = container_of(work, struct power_supply,
						deferred_register_work.work);

	if (psy->dev.parent)
		mutex_lock(&psy->dev.parent->mutex);

	power_supply_changed(psy);

	if (psy->dev.parent)
		mutex_unlock(&psy->dev.parent->mutex);
}

#ifdef CONFIG_OF
#include <linux/of.h>

static int __power_supply_populate_supplied_from(struct device *dev,
						 void *data)
{
	struct power_supply *psy = data;
	struct power_supply *epsy = dev_get_drvdata(dev);
	struct device_node *np;
	int i = 0;

	do {
		np = of_parse_phandle(psy->of_node, "power-supplies", i++);
		if (!np)
			break;

		if (np == epsy->of_node) {
			dev_info(&psy->dev, "%s: Found supply : %s\n",
				psy->desc->name, epsy->desc->name);
			psy->supplied_from[i-1] = (char *)epsy->desc->name;
			psy->num_supplies++;
			of_node_put(np);
			break;
		}
		of_node_put(np);
	} while (np);

	return 0;
}

static int power_supply_populate_supplied_from(struct power_supply *psy)
{
	int error;

	error = class_for_each_device(power_supply_class, NULL, psy,
				      __power_supply_populate_supplied_from);

	dev_dbg(&psy->dev, "%s %d\n", __func__, error);

	return error;
}

static int  __power_supply_find_supply_from_node(struct device *dev,
						 void *data)
{
	struct device_node *np = data;
	struct power_supply *epsy = dev_get_drvdata(dev);

	/* returning non-zero breaks out of class_for_each_device loop */
	if (epsy->of_node == np)
		return 1;

	return 0;
}

static int power_supply_find_supply_from_node(struct device_node *supply_node)
{
	int error;

	/*
	 * class_for_each_device() either returns its own errors or values
	 * returned by __power_supply_find_supply_from_node().
	 *
	 * __power_supply_find_supply_from_node() will return 0 (no match)
	 * or 1 (match).
	 *
	 * We return 0 if class_for_each_device() returned 1, -EPROBE_DEFER if
	 * it returned 0, or error as returned by it.
	 */
	error = class_for_each_device(power_supply_class, NULL, supply_node,
				       __power_supply_find_supply_from_node);

	return error ? (error == 1 ? 0 : error) : -EPROBE_DEFER;
}

static int power_supply_check_supplies(struct power_supply *psy)
{
	struct device_node *np;
	int cnt = 0;

	/* If there is already a list honor it */
	if (psy->supplied_from && psy->num_supplies > 0)
		return 0;

	/* No device node found, nothing to do */
	if (!psy->of_node)
		return 0;

	do {
		int ret;

		np = of_parse_phandle(psy->of_node, "power-supplies", cnt++);
		if (!np)
			break;

		ret = power_supply_find_supply_from_node(np);
		of_node_put(np);

		if (ret) {
			dev_dbg(&psy->dev, "Failed to find supply!\n");
			return ret;
		}
	} while (np);

	/* Missing valid "power-supplies" entries */
	if (cnt == 1)
		return 0;

	/* All supplies found, allocate char ** array for filling */
	psy->supplied_from = devm_kzalloc(&psy->dev, sizeof(psy->supplied_from),
					  GFP_KERNEL);
	if (!psy->supplied_from) {
		dev_err(&psy->dev, "Couldn't allocate memory for supply list\n");
		return -ENOMEM;
	}

	*psy->supplied_from = devm_kzalloc(&psy->dev,
					   sizeof(char *) * (cnt - 1),
					   GFP_KERNEL);
	if (!*psy->supplied_from) {
		dev_err(&psy->dev, "Couldn't allocate memory for supply list\n");
		return -ENOMEM;
	}

	return power_supply_populate_supplied_from(psy);
}
#else
static inline int power_supply_check_supplies(struct power_supply *psy)
{
	return 0;
}
#endif

static int __power_supply_am_i_supplied(struct device *dev, void *data)
{
	union power_supply_propval ret = {0,};
	struct power_supply *psy = data;
	struct power_supply *epsy = dev_get_drvdata(dev);

	if (__power_supply_is_supplied_by(epsy, psy))
		if (!epsy->desc->get_property(epsy, POWER_SUPPLY_PROP_ONLINE,
					&ret))
			return ret.intval;

	return 0;
}

int power_supply_am_i_supplied(struct power_supply *psy)
{
	int error;

	error = class_for_each_device(power_supply_class, NULL, psy,
				      __power_supply_am_i_supplied);

	dev_dbg(&psy->dev, "%s %d\n", __func__, error);

	return error;
}
EXPORT_SYMBOL_GPL(power_supply_am_i_supplied);

static int __power_supply_is_system_supplied(struct device *dev, void *data)
{
	union power_supply_propval ret = {0,};
	struct power_supply *psy = dev_get_drvdata(dev);
	unsigned int *count = data;

	(*count)++;
	if (psy->desc->type != POWER_SUPPLY_TYPE_BATTERY)
		if (!psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE,
					&ret))
			return ret.intval;

	return 0;
}

int power_supply_is_system_supplied(void)
{
	int error;
	unsigned int count = 0;

	error = class_for_each_device(power_supply_class, NULL, &count,
				      __power_supply_is_system_supplied);

	/*
	 * If no power class device was found at all, most probably we are
	 * running on a desktop system, so assume we are on mains power.
	 */
	if (count == 0)
		return 1;

	return error;
}
EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);

int power_supply_set_battery_charged(struct power_supply *psy)
{
	if (atomic_read(&psy->use_cnt) >= 0 &&
			psy->desc->type == POWER_SUPPLY_TYPE_BATTERY &&
			psy->desc->set_charged) {
		psy->desc->set_charged(psy);
		return 0;
	}

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(power_supply_set_battery_charged);

static int power_supply_match_device_by_name(struct device *dev, const void *data)
{
	const char *name = data;
	struct power_supply *psy = dev_get_drvdata(dev);

	return strcmp(psy->desc->name, name) == 0;
}

/**
 * power_supply_get_by_name() - Search for a power supply and returns its ref
 * @name: Power supply name to fetch
 *
 * If power supply was found, it increases reference count for the
 * internal power supply's device. The user should power_supply_put()
 * after usage.
 *
 * Return: On success returns a reference to a power supply with
 * matching name equals to @name, a NULL otherwise.
 */
struct power_supply *power_supply_get_by_name(const char *name)
{
	struct power_supply *psy = NULL;
	struct device *dev = class_find_device(power_supply_class, NULL, name,
					power_supply_match_device_by_name);

	if (dev) {
		psy = dev_get_drvdata(dev);
		atomic_inc(&psy->use_cnt);
	}

	return psy;
}
EXPORT_SYMBOL_GPL(power_supply_get_by_name);

/**
 * power_supply_put() - Drop reference obtained with power_supply_get_by_name
 * @psy: Reference to put
 *
 * The reference to power supply should be put before unregistering
 * the power supply.
 */
void power_supply_put(struct power_supply *psy)
{
	might_sleep();

	atomic_dec(&psy->use_cnt);
	put_device(&psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_put);

#ifdef CONFIG_OF
static int power_supply_match_device_node(struct device *dev, const void *data)
{
	return dev->parent && dev->parent->of_node == data;
}

/**
 * power_supply_get_by_phandle() - Search for a power supply and returns its ref
 * @np: Pointer to device node holding phandle property
 * @phandle_name: Name of property holding a power supply name
 *
 * If power supply was found, it increases reference count for the
 * internal power supply's device. The user should power_supply_put()
 * after usage.
 *
 * Return: On success returns a reference to a power supply with
 * matching name equals to value under @property, NULL or ERR_PTR otherwise.
 */
struct power_supply *power_supply_get_by_phandle(struct device_node *np,
							const char *property)
{
	struct device_node *power_supply_np;
	struct power_supply *psy = NULL;
	struct device *dev;

	power_supply_np = of_parse_phandle(np, property, 0);
	if (!power_supply_np)
		return ERR_PTR(-ENODEV);

	dev = class_find_device(power_supply_class, NULL, power_supply_np,
						power_supply_match_device_node);

	of_node_put(power_supply_np);

	if (dev) {
		psy = dev_get_drvdata(dev);
		atomic_inc(&psy->use_cnt);
	}

	return psy;
}
EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
#endif /* CONFIG_OF */

int power_supply_get_property(struct power_supply *psy,
			    enum power_supply_property psp,
			    union power_supply_propval *val)
{
	if (atomic_read(&psy->use_cnt) <= 0)
		return -ENODEV;

	return psy->desc->get_property(psy, psp, val);
}
EXPORT_SYMBOL_GPL(power_supply_get_property);

int power_supply_set_property(struct power_supply *psy,
			    enum power_supply_property psp,
			    const union power_supply_propval *val)
{
	if (atomic_read(&psy->use_cnt) <= 0 || !psy->desc->set_property)
		return -ENODEV;

	return psy->desc->set_property(psy, psp, val);
}
EXPORT_SYMBOL_GPL(power_supply_set_property);

int power_supply_property_is_writeable(struct power_supply *psy,
					enum power_supply_property psp)
{
	if (atomic_read(&psy->use_cnt) <= 0 ||
			!psy->desc->property_is_writeable)
		return -ENODEV;

	return psy->desc->property_is_writeable(psy, psp);
}
EXPORT_SYMBOL_GPL(power_supply_property_is_writeable);

void power_supply_external_power_changed(struct power_supply *psy)
{
	if (atomic_read(&psy->use_cnt) <= 0 ||
			!psy->desc->external_power_changed)
		return;

	psy->desc->external_power_changed(psy);
}
EXPORT_SYMBOL_GPL(power_supply_external_power_changed);

int power_supply_powers(struct power_supply *psy, struct device *dev)
{
	return sysfs_create_link(&psy->dev.kobj, &dev->kobj, "powers");
}
EXPORT_SYMBOL_GPL(power_supply_powers);

static void power_supply_dev_release(struct device *dev)
{
	struct power_supply *psy = container_of(dev, struct power_supply, dev);
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
	kfree(psy);
}

int power_supply_reg_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_register(&power_supply_notifier, nb);
}
EXPORT_SYMBOL_GPL(power_supply_reg_notifier);

void power_supply_unreg_notifier(struct notifier_block *nb)
{
	atomic_notifier_chain_unregister(&power_supply_notifier, nb);
}
EXPORT_SYMBOL_GPL(power_supply_unreg_notifier);

#ifdef CONFIG_THERMAL
static int power_supply_read_temp(struct thermal_zone_device *tzd,
		unsigned long *temp)
{
	struct power_supply *psy;
	union power_supply_propval val;
	int ret;

	WARN_ON(tzd == NULL);
	psy = tzd->devdata;
	ret = psy->desc->get_property(psy, POWER_SUPPLY_PROP_TEMP, &val);

	/* Convert tenths of degree Celsius to milli degree Celsius. */
	if (!ret)
		*temp = val.intval * 100;

	return ret;
}

static struct thermal_zone_device_ops psy_tzd_ops = {
	.get_temp = power_supply_read_temp,
};

static int psy_register_thermal(struct power_supply *psy)
{
	int i;

	if (psy->desc->no_thermal)
		return 0;

	/* Register battery zone device psy reports temperature */
	for (i = 0; i < psy->desc->num_properties; i++) {
		if (psy->desc->properties[i] == POWER_SUPPLY_PROP_TEMP) {
			psy->tzd = thermal_zone_device_register(psy->desc->name,
					0, 0, psy, &psy_tzd_ops, NULL, 0, 0);
			return PTR_ERR_OR_ZERO(psy->tzd);
		}
	}
	return 0;
}

static void psy_unregister_thermal(struct power_supply *psy)
{
	if (IS_ERR_OR_NULL(psy->tzd))
		return;
	thermal_zone_device_unregister(psy->tzd);
}

/* thermal cooling device callbacks */
static int ps_get_max_charge_cntl_limit(struct thermal_cooling_device *tcd,
					unsigned long *state)
{
	struct power_supply *psy;
	union power_supply_propval val;
	int ret;

	psy = tcd->devdata;
	ret = psy->desc->get_property(psy,
		POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX, &val);
	if (!ret)
		*state = val.intval;

	return ret;
}

static int ps_get_cur_chrage_cntl_limit(struct thermal_cooling_device *tcd,
					unsigned long *state)
{
	struct power_supply *psy;
	union power_supply_propval val;
	int ret;

	psy = tcd->devdata;
	ret = psy->desc->get_property(psy,
		POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);
	if (!ret)
		*state = val.intval;

	return ret;
}

static int ps_set_cur_charge_cntl_limit(struct thermal_cooling_device *tcd,
					unsigned long state)
{
	struct power_supply *psy;
	union power_supply_propval val;
	int ret;

	psy = tcd->devdata;
	val.intval = state;
	ret = psy->desc->set_property(psy,
		POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT, &val);

	return ret;
}

static struct thermal_cooling_device_ops psy_tcd_ops = {
	.get_max_state = ps_get_max_charge_cntl_limit,
	.get_cur_state = ps_get_cur_chrage_cntl_limit,
	.set_cur_state = ps_set_cur_charge_cntl_limit,
};

static int psy_register_cooler(struct power_supply *psy)
{
	int i;

	/* Register for cooling device if psy can control charging */
	for (i = 0; i < psy->desc->num_properties; i++) {
		if (psy->desc->properties[i] ==
				POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT) {
			psy->tcd = thermal_cooling_device_register(
							(char *)psy->desc->name,
							psy, &psy_tcd_ops);
			return PTR_ERR_OR_ZERO(psy->tcd);
		}
	}
	return 0;
}

static void psy_unregister_cooler(struct power_supply *psy)
{
	if (IS_ERR_OR_NULL(psy->tcd))
		return;
	thermal_cooling_device_unregister(psy->tcd);
}
#else
static int psy_register_thermal(struct power_supply *psy)
{
	return 0;
}

static void psy_unregister_thermal(struct power_supply *psy)
{
}

static int psy_register_cooler(struct power_supply *psy)
{
	return 0;
}

static void psy_unregister_cooler(struct power_supply *psy)
{
}
#endif

static struct power_supply *__must_check
__power_supply_register(struct device *parent,
				   const struct power_supply_desc *desc,
				   const struct power_supply_config *cfg,
				   bool ws)
{
	struct device *dev;
	struct power_supply *psy;
	int rc;

	if (!parent)
		pr_warn("%s: Expected proper parent device for '%s'\n",
			__func__, desc->name);

	psy = kzalloc(sizeof(*psy), GFP_KERNEL);
	if (!psy)
		return ERR_PTR(-ENOMEM);

	dev = &psy->dev;

	device_initialize(dev);

	dev->class = power_supply_class;
	dev->type = &power_supply_dev_type;
	dev->parent = parent;
	dev->release = power_supply_dev_release;
	dev_set_drvdata(dev, psy);
	psy->desc = desc;
	if (cfg) {
		psy->drv_data = cfg->drv_data;
		psy->of_node = cfg->of_node;
		psy->supplied_to = cfg->supplied_to;
		psy->num_supplicants = cfg->num_supplicants;
	}

	rc = dev_set_name(dev, "%s", desc->name);
	if (rc)
		goto dev_set_name_failed;

	INIT_WORK(&psy->changed_work, power_supply_changed_work);
	INIT_DELAYED_WORK(&psy->deferred_register_work,
			  power_supply_deferred_register_work);

	rc = power_supply_check_supplies(psy);
	if (rc) {
		dev_info(dev, "Not all required supplies found, defer probe\n");
		goto check_supplies_failed;
	}

	spin_lock_init(&psy->changed_lock);
	rc = device_init_wakeup(dev, ws);
	if (rc)
		goto wakeup_init_failed;

	rc = device_add(dev);
	if (rc)
		goto device_add_failed;

	rc = psy_register_thermal(psy);
	if (rc)
		goto register_thermal_failed;

	rc = psy_register_cooler(psy);
	if (rc)
		goto register_cooler_failed;

	rc = power_supply_create_triggers(psy);
	if (rc)
		goto create_triggers_failed;

	/*
	 * Update use_cnt after any uevents (most notably from device_add()).
	 * We are here still during driver's probe but
	 * the power_supply_uevent() calls back driver's get_property
	 * method so:
	 * 1. Driver did not assigned the returned struct power_supply,
	 * 2. Driver could not finish initialization (anything in its probe
	 *    after calling power_supply_register()).
	 */
	atomic_inc(&psy->use_cnt);

	queue_delayed_work(system_power_efficient_wq,
			   &psy->deferred_register_work,
			   POWER_SUPPLY_DEFERRED_REGISTER_TIME);

	return psy;

create_triggers_failed:
	psy_unregister_cooler(psy);
register_cooler_failed:
	psy_unregister_thermal(psy);
register_thermal_failed:
	device_del(dev);
device_add_failed:
wakeup_init_failed:
check_supplies_failed:
dev_set_name_failed:
	put_device(dev);
	return ERR_PTR(rc);
}

/**
 * power_supply_register() - Register new power supply
 * @parent:	Device to be a parent of power supply's device, usually
 *		the device which probe function calls this
 * @desc:	Description of power supply, must be valid through whole
 *		lifetime of this power supply
 * @cfg:	Run-time specific configuration accessed during registering,
 *		may be NULL
 *
 * Return: A pointer to newly allocated power_supply on success
 * or ERR_PTR otherwise.
 * Use power_supply_unregister() on returned power_supply pointer to release
 * resources.
 */
struct power_supply *__must_check power_supply_register(struct device *parent,
		const struct power_supply_desc *desc,
		const struct power_supply_config *cfg)
{
	return __power_supply_register(parent, desc, cfg, true);
}
EXPORT_SYMBOL_GPL(power_supply_register);

/**
 * power_supply_register() - Register new non-waking-source power supply
 * @parent:	Device to be a parent of power supply's device, usually
 *		the device which probe function calls this
 * @desc:	Description of power supply, must be valid through whole
 *		lifetime of this power supply
 * @cfg:	Run-time specific configuration accessed during registering,
 *		may be NULL
 *
 * Return: A pointer to newly allocated power_supply on success
 * or ERR_PTR otherwise.
 * Use power_supply_unregister() on returned power_supply pointer to release
 * resources.
 */
struct power_supply *__must_check
power_supply_register_no_ws(struct device *parent,
		const struct power_supply_desc *desc,
		const struct power_supply_config *cfg)
{
	return __power_supply_register(parent, desc, cfg, false);
}
EXPORT_SYMBOL_GPL(power_supply_register_no_ws);

static void devm_power_supply_release(struct device *dev, void *res)
{
	struct power_supply **psy = res;

	power_supply_unregister(*psy);
}

/**
 * power_supply_register() - Register managed power supply
 * @parent:	Device to be a parent of power supply's device, usually
 *		the device which probe function calls this
 * @desc:	Description of power supply, must be valid through whole
 *		lifetime of this power supply
 * @cfg:	Run-time specific configuration accessed during registering,
 *		may be NULL
 *
 * Return: A pointer to newly allocated power_supply on success
 * or ERR_PTR otherwise.
 * The returned power_supply pointer will be automatically unregistered
 * on driver detach.
 */
struct power_supply *__must_check
devm_power_supply_register(struct device *parent,
		const struct power_supply_desc *desc,
		const struct power_supply_config *cfg)
{
	struct power_supply **ptr, *psy;

	ptr = devres_alloc(devm_power_supply_release, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)
		return ERR_PTR(-ENOMEM);
	psy = __power_supply_register(parent, desc, cfg, true);
	if (IS_ERR(psy)) {
		devres_free(ptr);
	} else {
		*ptr = psy;
		devres_add(parent, ptr);
	}
	return psy;
}
EXPORT_SYMBOL_GPL(devm_power_supply_register);

/**
 * power_supply_register() - Register managed non-waking-source power supply
 * @parent:	Device to be a parent of power supply's device, usually
 *		the device which probe function calls this
 * @desc:	Description of power supply, must be valid through whole
 *		lifetime of this power supply
 * @cfg:	Run-time specific configuration accessed during registering,
 *		may be NULL
 *
 * Return: A pointer to newly allocated power_supply on success
 * or ERR_PTR otherwise.
 * The returned power_supply pointer will be automatically unregistered
 * on driver detach.
 */
struct power_supply *__must_check
devm_power_supply_register_no_ws(struct device *parent,
		const struct power_supply_desc *desc,
		const struct power_supply_config *cfg)
{
	struct power_supply **ptr, *psy;

	ptr = devres_alloc(devm_power_supply_release, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)
		return ERR_PTR(-ENOMEM);
	psy = __power_supply_register(parent, desc, cfg, false);
	if (IS_ERR(psy)) {
		devres_free(ptr);
	} else {
		*ptr = psy;
		devres_add(parent, ptr);
	}
	return psy;
}
EXPORT_SYMBOL_GPL(devm_power_supply_register_no_ws);

/**
 * power_supply_unregister() - Remove this power supply from system
 * @psy:	Pointer to power supply to unregister
 *
 * Remove this power supply from the system. The resources of power supply
 * will be freed here or on last power_supply_put() call.
 */
void power_supply_unregister(struct power_supply *psy)
{
	WARN_ON(atomic_dec_return(&psy->use_cnt));
	cancel_work_sync(&psy->changed_work);
	cancel_delayed_work_sync(&psy->deferred_register_work);
	sysfs_remove_link(&psy->dev.kobj, "powers");
	power_supply_remove_triggers(psy);
	psy_unregister_cooler(psy);
	psy_unregister_thermal(psy);
	device_init_wakeup(&psy->dev, false);
	device_unregister(&psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_unregister);

void *power_supply_get_drvdata(struct power_supply *psy)
{
	return psy->drv_data;
}
EXPORT_SYMBOL_GPL(power_supply_get_drvdata);

static int __init power_supply_class_init(void)
{
	power_supply_class = class_create(THIS_MODULE, "power_supply");

	if (IS_ERR(power_supply_class))
		return PTR_ERR(power_supply_class);

	power_supply_class->dev_uevent = power_supply_uevent;
	power_supply_init_attrs(&power_supply_dev_type);

	return 0;
}

static void __exit power_supply_class_exit(void)
{
	class_destroy(power_supply_class);
}

subsys_initcall(power_supply_class_init);
module_exit(power_supply_class_exit);

MODULE_DESCRIPTION("Universal power supply monitor class");
MODULE_AUTHOR("Ian Molton <spyro@f2s.com>, "
	      "Szabolcs Gyurko, "
	      "Anton Vorontsov <cbou@mail.ru>");
MODULE_LICENSE("GPL");