summaryrefslogtreecommitdiffstats
path: root/drivers/iio/adc/ab8500-gpadc.c
blob: 3b1bdd0b531d482d6cc133371298ab512bbf2c48 (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
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Arun R Murthy <arun.murthy@stericsson.com>
 * Author: Daniel Willerud <daniel.willerud@stericsson.com>
 * Author: Johan Palsson <johan.palsson@stericsson.com>
 * Author: M'boumba Cedric Madianga
 * Author: Linus Walleij <linus.walleij@linaro.org>
 *
 * AB8500 General Purpose ADC driver. The AB8500 uses reference voltages:
 * VinVADC, and VADC relative to GND to do its job. It monitors main and backup
 * battery voltages, AC (mains) voltage, USB cable voltage, as well as voltages
 * representing the temperature of the chip die and battery, accessory
 * detection by resistance measurements using relative voltages and GSM burst
 * information.
 *
 * Some of the voltages are measured on external pins on the IC, such as
 * battery temperature or "ADC aux" 1 and 2. Other voltages are internal rails
 * from other parts of the ASIC such as main charger voltage, main and battery
 * backup voltage or USB VBUS voltage. For this reason drivers for other
 * parts of the system are required to obtain handles to the ADC to do work
 * for them and the IIO driver provides arbitration among these consumers.
 */
#include <linux/init.h>
#include <linux/bits.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
#include <linux/random.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500.h>

/* GPADC register offsets and bit definitions */

#define AB8500_GPADC_CTRL1_REG		0x00
/* GPADC control register 1 bits */
#define AB8500_GPADC_CTRL1_DISABLE		0x00
#define AB8500_GPADC_CTRL1_ENABLE		BIT(0)
#define AB8500_GPADC_CTRL1_TRIG_ENA		BIT(1)
#define AB8500_GPADC_CTRL1_START_SW_CONV	BIT(2)
#define AB8500_GPADC_CTRL1_BTEMP_PULL_UP	BIT(3)
/* 0 = use rising edge, 1 = use falling edge */
#define AB8500_GPADC_CTRL1_TRIG_EDGE		BIT(4)
/* 0 = use VTVOUT, 1 = use VRTC as pull-up supply for battery temp NTC */
#define AB8500_GPADC_CTRL1_PUPSUPSEL		BIT(5)
#define AB8500_GPADC_CTRL1_BUF_ENA		BIT(6)
#define AB8500_GPADC_CTRL1_ICHAR_ENA		BIT(7)

#define AB8500_GPADC_CTRL2_REG		0x01
#define AB8500_GPADC_CTRL3_REG		0x02
/*
 * GPADC control register 2 and 3 bits
 * the bit layout is the same for SW and HW conversion set-up
 */
#define AB8500_GPADC_CTRL2_AVG_1		0x00
#define AB8500_GPADC_CTRL2_AVG_4		BIT(5)
#define AB8500_GPADC_CTRL2_AVG_8		BIT(6)
#define AB8500_GPADC_CTRL2_AVG_16		(BIT(5) | BIT(6))

enum ab8500_gpadc_channel {
	AB8500_GPADC_CHAN_UNUSED = 0x00,
	AB8500_GPADC_CHAN_BAT_CTRL = 0x01,
	AB8500_GPADC_CHAN_BAT_TEMP = 0x02,
	/* This is not used on AB8505 */
	AB8500_GPADC_CHAN_MAIN_CHARGER = 0x03,
	AB8500_GPADC_CHAN_ACC_DET_1 = 0x04,
	AB8500_GPADC_CHAN_ACC_DET_2 = 0x05,
	AB8500_GPADC_CHAN_ADC_AUX_1 = 0x06,
	AB8500_GPADC_CHAN_ADC_AUX_2 = 0x07,
	AB8500_GPADC_CHAN_VBAT_A = 0x08,
	AB8500_GPADC_CHAN_VBUS = 0x09,
	AB8500_GPADC_CHAN_MAIN_CHARGER_CURRENT = 0x0a,
	AB8500_GPADC_CHAN_USB_CHARGER_CURRENT = 0x0b,
	AB8500_GPADC_CHAN_BACKUP_BAT = 0x0c,
	/* Only on AB8505 */
	AB8505_GPADC_CHAN_DIE_TEMP = 0x0d,
	AB8500_GPADC_CHAN_ID = 0x0e,
	AB8500_GPADC_CHAN_INTERNAL_TEST_1 = 0x0f,
	AB8500_GPADC_CHAN_INTERNAL_TEST_2 = 0x10,
	AB8500_GPADC_CHAN_INTERNAL_TEST_3 = 0x11,
	/* FIXME: Applicable to all ASIC variants? */
	AB8500_GPADC_CHAN_XTAL_TEMP = 0x12,
	AB8500_GPADC_CHAN_VBAT_TRUE_MEAS = 0x13,
	/* FIXME: Doesn't seem to work with pure AB8500 */
	AB8500_GPADC_CHAN_BAT_CTRL_AND_IBAT = 0x1c,
	AB8500_GPADC_CHAN_VBAT_MEAS_AND_IBAT = 0x1d,
	AB8500_GPADC_CHAN_VBAT_TRUE_MEAS_AND_IBAT = 0x1e,
	AB8500_GPADC_CHAN_BAT_TEMP_AND_IBAT = 0x1f,
	/*
	 * Virtual channel used only for ibat conversion to ampere.
	 * Battery current conversion (ibat) cannot be requested as a
	 * single conversion but it is always requested in combination
	 * with other input requests.
	 */
	AB8500_GPADC_CHAN_IBAT_VIRTUAL = 0xFF,
};

#define AB8500_GPADC_AUTO_TIMER_REG	0x03

#define AB8500_GPADC_STAT_REG		0x04
#define AB8500_GPADC_STAT_BUSY		BIT(0)

#define AB8500_GPADC_MANDATAL_REG	0x05
#define AB8500_GPADC_MANDATAH_REG	0x06
#define AB8500_GPADC_AUTODATAL_REG	0x07
#define AB8500_GPADC_AUTODATAH_REG	0x08
#define AB8500_GPADC_MUX_CTRL_REG	0x09
#define AB8540_GPADC_MANDATA2L_REG	0x09
#define AB8540_GPADC_MANDATA2H_REG	0x0A
#define AB8540_GPADC_APEAAX_REG		0x10
#define AB8540_GPADC_APEAAT_REG		0x11
#define AB8540_GPADC_APEAAM_REG		0x12
#define AB8540_GPADC_APEAAH_REG		0x13
#define AB8540_GPADC_APEAAL_REG		0x14

/*
 * OTP register offsets
 * Bank : 0x15
 */
#define AB8500_GPADC_CAL_1	0x0F
#define AB8500_GPADC_CAL_2	0x10
#define AB8500_GPADC_CAL_3	0x11
#define AB8500_GPADC_CAL_4	0x12
#define AB8500_GPADC_CAL_5	0x13
#define AB8500_GPADC_CAL_6	0x14
#define AB8500_GPADC_CAL_7	0x15
/* New calibration for 8540 */
#define AB8540_GPADC_OTP4_REG_7	0x38
#define AB8540_GPADC_OTP4_REG_6	0x39
#define AB8540_GPADC_OTP4_REG_5	0x3A

#define AB8540_GPADC_DIS_ZERO	0x00
#define AB8540_GPADC_EN_VBIAS_XTAL_TEMP	0x02

/* GPADC constants from AB8500 spec, UM0836 */
#define AB8500_ADC_RESOLUTION		1024
#define AB8500_ADC_CH_BTEMP_MIN		0
#define AB8500_ADC_CH_BTEMP_MAX		1350
#define AB8500_ADC_CH_DIETEMP_MIN	0
#define AB8500_ADC_CH_DIETEMP_MAX	1350
#define AB8500_ADC_CH_CHG_V_MIN		0
#define AB8500_ADC_CH_CHG_V_MAX		20030
#define AB8500_ADC_CH_ACCDET2_MIN	0
#define AB8500_ADC_CH_ACCDET2_MAX	2500
#define AB8500_ADC_CH_VBAT_MIN		2300
#define AB8500_ADC_CH_VBAT_MAX		4800
#define AB8500_ADC_CH_CHG_I_MIN		0
#define AB8500_ADC_CH_CHG_I_MAX		1500
#define AB8500_ADC_CH_BKBAT_MIN		0
#define AB8500_ADC_CH_BKBAT_MAX		3200

/* GPADC constants from AB8540 spec */
#define AB8500_ADC_CH_IBAT_MIN		(-6000) /* mA range measured by ADC for ibat */
#define AB8500_ADC_CH_IBAT_MAX		6000
#define AB8500_ADC_CH_IBAT_MIN_V	(-60)	/* mV range measured by ADC for ibat */
#define AB8500_ADC_CH_IBAT_MAX_V	60
#define AB8500_GPADC_IBAT_VDROP_L	(-56)  /* mV */
#define AB8500_GPADC_IBAT_VDROP_H	56

/* This is used to not lose precision when dividing to get gain and offset */
#define AB8500_GPADC_CALIB_SCALE	1000
/*
 * Number of bits shift used to not lose precision
 * when dividing to get ibat gain.
 */
#define AB8500_GPADC_CALIB_SHIFT_IBAT	20

/* Time in ms before disabling regulator */
#define AB8500_GPADC_AUTOSUSPEND_DELAY	1

#define AB8500_GPADC_CONVERSION_TIME	500 /* ms */

enum ab8500_cal_channels {
	AB8500_CAL_VMAIN = 0,
	AB8500_CAL_BTEMP,
	AB8500_CAL_VBAT,
	AB8500_CAL_IBAT,
	AB8500_CAL_NR,
};

/**
 * struct ab8500_adc_cal_data - Table for storing gain and offset for the
 * calibrated ADC channels
 * @gain: Gain of the ADC channel
 * @offset: Offset of the ADC channel
 * @otp_calib_hi: Calibration from OTP
 * @otp_calib_lo: Calibration from OTP
 */
struct ab8500_adc_cal_data {
	s64 gain;
	s64 offset;
	u16 otp_calib_hi;
	u16 otp_calib_lo;
};

/**
 * struct ab8500_gpadc_chan_info - per-channel GPADC info
 * @name: name of the channel
 * @id: the internal AB8500 ID number for the channel
 * @hardware_control: indicate that we want to use hardware ADC control
 * on this channel, the default is software ADC control. Hardware control
 * is normally only used to test the battery voltage during GSM bursts
 * and needs a hardware trigger on the GPADCTrig pin of the ASIC.
 * @falling_edge: indicate that we want to trigger on falling edge
 * rather than rising edge, rising edge is the default
 * @avg_sample: how many samples to average: must be 1, 4, 8 or 16.
 * @trig_timer: how long to wait for the trigger, in 32kHz periods:
 * 0 .. 255 periods
 */
struct ab8500_gpadc_chan_info {
	const char *name;
	u8 id;
	bool hardware_control;
	bool falling_edge;
	u8 avg_sample;
	u8 trig_timer;
};

/**
 * struct ab8500_gpadc - AB8500 GPADC device information
 * @dev: pointer to the containing device
 * @ab8500: pointer to the parent AB8500 device
 * @chans: internal per-channel information container
 * @nchans: number of channels
 * @complete: pointer to the completion that indicates
 * the completion of an gpadc conversion cycle
 * @vddadc: pointer to the regulator supplying VDDADC
 * @irq_sw: interrupt number that is used by gpadc for software ADC conversion
 * @irq_hw: interrupt number that is used by gpadc for hardware ADC conversion
 * @cal_data: array of ADC calibration data structs
 */
struct ab8500_gpadc {
	struct device *dev;
	struct ab8500 *ab8500;
	struct ab8500_gpadc_chan_info *chans;
	unsigned int nchans;
	struct completion complete;
	struct regulator *vddadc;
	int irq_sw;
	int irq_hw;
	struct ab8500_adc_cal_data cal_data[AB8500_CAL_NR];
};

static struct ab8500_gpadc_chan_info *
ab8500_gpadc_get_channel(struct ab8500_gpadc *gpadc, u8 chan)
{
	struct ab8500_gpadc_chan_info *ch;
	int i;

	for (i = 0; i < gpadc->nchans; i++) {
		ch = &gpadc->chans[i];
		if (ch->id == chan)
			break;
	}
	if (i == gpadc->nchans)
		return NULL;

	return ch;
}

/**
 * ab8500_gpadc_ad_to_voltage() - Convert a raw ADC value to a voltage
 * @gpadc: GPADC instance
 * @ch: the sampled channel this raw value is coming from
 * @ad_value: the raw value
 */
static int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc,
				      enum ab8500_gpadc_channel ch,
				      int ad_value)
{
	int res;

	switch (ch) {
	case AB8500_GPADC_CHAN_MAIN_CHARGER:
		/* No calibration data available: just interpolate */
		if (!gpadc->cal_data[AB8500_CAL_VMAIN].gain) {
			res = AB8500_ADC_CH_CHG_V_MIN + (AB8500_ADC_CH_CHG_V_MAX -
				AB8500_ADC_CH_CHG_V_MIN) * ad_value /
				AB8500_ADC_RESOLUTION;
			break;
		}
		/* Here we can use calibration */
		res = (int) (ad_value * gpadc->cal_data[AB8500_CAL_VMAIN].gain +
			gpadc->cal_data[AB8500_CAL_VMAIN].offset) / AB8500_GPADC_CALIB_SCALE;
		break;

	case AB8500_GPADC_CHAN_BAT_CTRL:
	case AB8500_GPADC_CHAN_BAT_TEMP:
	case AB8500_GPADC_CHAN_ACC_DET_1:
	case AB8500_GPADC_CHAN_ADC_AUX_1:
	case AB8500_GPADC_CHAN_ADC_AUX_2:
	case AB8500_GPADC_CHAN_XTAL_TEMP:
		/* No calibration data available: just interpolate */
		if (!gpadc->cal_data[AB8500_CAL_BTEMP].gain) {
			res = AB8500_ADC_CH_BTEMP_MIN + (AB8500_ADC_CH_BTEMP_MAX -
				AB8500_ADC_CH_BTEMP_MIN) * ad_value /
				AB8500_ADC_RESOLUTION;
			break;
		}
		/* Here we can use calibration */
		res = (int) (ad_value * gpadc->cal_data[AB8500_CAL_BTEMP].gain +
			gpadc->cal_data[AB8500_CAL_BTEMP].offset) / AB8500_GPADC_CALIB_SCALE;
		break;

	case AB8500_GPADC_CHAN_VBAT_A:
	case AB8500_GPADC_CHAN_VBAT_TRUE_MEAS:
		/* No calibration data available: just interpolate */
		if (!gpadc->cal_data[AB8500_CAL_VBAT].gain) {
			res = AB8500_ADC_CH_VBAT_MIN + (AB8500_ADC_CH_VBAT_MAX -
				AB8500_ADC_CH_VBAT_MIN) * ad_value /
				AB8500_ADC_RESOLUTION;
			break;
		}
		/* Here we can use calibration */
		res = (int) (ad_value * gpadc->cal_data[AB8500_CAL_VBAT].gain +
			gpadc->cal_data[AB8500_CAL_VBAT].offset) / AB8500_GPADC_CALIB_SCALE;
		break;

	case AB8505_GPADC_CHAN_DIE_TEMP:
		res = AB8500_ADC_CH_DIETEMP_MIN +
			(AB8500_ADC_CH_DIETEMP_MAX - AB8500_ADC_CH_DIETEMP_MIN) * ad_value /
			AB8500_ADC_RESOLUTION;
		break;

	case AB8500_GPADC_CHAN_ACC_DET_2:
		res = AB8500_ADC_CH_ACCDET2_MIN +
			(AB8500_ADC_CH_ACCDET2_MAX - AB8500_ADC_CH_ACCDET2_MIN) * ad_value /
			AB8500_ADC_RESOLUTION;
		break;

	case AB8500_GPADC_CHAN_VBUS:
		res = AB8500_ADC_CH_CHG_V_MIN +
			(AB8500_ADC_CH_CHG_V_MAX - AB8500_ADC_CH_CHG_V_MIN) * ad_value /
			AB8500_ADC_RESOLUTION;
		break;

	case AB8500_GPADC_CHAN_MAIN_CHARGER_CURRENT:
	case AB8500_GPADC_CHAN_USB_CHARGER_CURRENT:
		res = AB8500_ADC_CH_CHG_I_MIN +
			(AB8500_ADC_CH_CHG_I_MAX - AB8500_ADC_CH_CHG_I_MIN) * ad_value /
			AB8500_ADC_RESOLUTION;
		break;

	case AB8500_GPADC_CHAN_BACKUP_BAT:
		res = AB8500_ADC_CH_BKBAT_MIN +
			(AB8500_ADC_CH_BKBAT_MAX - AB8500_ADC_CH_BKBAT_MIN) * ad_value /
			AB8500_ADC_RESOLUTION;
		break;

	case AB8500_GPADC_CHAN_IBAT_VIRTUAL:
		/* No calibration data available: just interpolate */
		if (!gpadc->cal_data[AB8500_CAL_IBAT].gain) {
			res = AB8500_ADC_CH_IBAT_MIN + (AB8500_ADC_CH_IBAT_MAX -
				AB8500_ADC_CH_IBAT_MIN) * ad_value /
				AB8500_ADC_RESOLUTION;
			break;
		}
		/* Here we can use calibration */
		res = (int) (ad_value * gpadc->cal_data[AB8500_CAL_IBAT].gain +
				gpadc->cal_data[AB8500_CAL_IBAT].offset)
				>> AB8500_GPADC_CALIB_SHIFT_IBAT;
		break;

	default:
		dev_err(gpadc->dev,
			"unknown channel ID: %d, not possible to convert\n",
			ch);
		res = -EINVAL;
		break;

	}

	return res;
}

static int ab8500_gpadc_read(struct ab8500_gpadc *gpadc,
			     const struct ab8500_gpadc_chan_info *ch,
			     int *ibat)
{
	int ret;
	int looplimit = 0;
	unsigned long completion_timeout;
	u8 val;
	u8 low_data, high_data, low_data2, high_data2;
	u8 ctrl1;
	u8 ctrl23;
	unsigned int delay_min = 0;
	unsigned int delay_max = 0;
	u8 data_low_addr, data_high_addr;

	if (!gpadc)
		return -ENODEV;

	/* check if conversion is supported */
	if ((gpadc->irq_sw <= 0) && !ch->hardware_control)
		return -ENOTSUPP;
	if ((gpadc->irq_hw <= 0) && ch->hardware_control)
		return -ENOTSUPP;

	/* Enable vddadc by grabbing PM runtime */
	pm_runtime_get_sync(gpadc->dev);

	/* Check if ADC is not busy, lock and proceed */
	do {
		ret = abx500_get_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
		if (ret < 0)
			goto out;
		if (!(val & AB8500_GPADC_STAT_BUSY))
			break;
		msleep(20);
	} while (++looplimit < 10);
	if (looplimit >= 10 && (val & AB8500_GPADC_STAT_BUSY)) {
		dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
		ret = -EINVAL;
		goto out;
	}

	/* Enable GPADC */
	ctrl1 = AB8500_GPADC_CTRL1_ENABLE;

	/* Select the channel source and set average samples */
	switch (ch->avg_sample) {
	case 1:
		ctrl23 = ch->id | AB8500_GPADC_CTRL2_AVG_1;
		break;
	case 4:
		ctrl23 = ch->id | AB8500_GPADC_CTRL2_AVG_4;
		break;
	case 8:
		ctrl23 = ch->id | AB8500_GPADC_CTRL2_AVG_8;
		break;
	default:
		ctrl23 = ch->id | AB8500_GPADC_CTRL2_AVG_16;
		break;
	}

	if (ch->hardware_control) {
		ret = abx500_set_register_interruptible(gpadc->dev,
				AB8500_GPADC, AB8500_GPADC_CTRL3_REG, ctrl23);
		ctrl1 |= AB8500_GPADC_CTRL1_TRIG_ENA;
		if (ch->falling_edge)
			ctrl1 |= AB8500_GPADC_CTRL1_TRIG_EDGE;
	} else {
		ret = abx500_set_register_interruptible(gpadc->dev,
				AB8500_GPADC, AB8500_GPADC_CTRL2_REG, ctrl23);
	}
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: set avg samples failed\n");
		goto out;
	}

	/*
	 * Enable ADC, buffering, select rising edge and enable ADC path
	 * charging current sense if it needed, ABB 3.0 needs some special
	 * treatment too.
	 */
	switch (ch->id) {
	case AB8500_GPADC_CHAN_MAIN_CHARGER_CURRENT:
	case AB8500_GPADC_CHAN_USB_CHARGER_CURRENT:
		ctrl1 |= AB8500_GPADC_CTRL1_BUF_ENA |
			AB8500_GPADC_CTRL1_ICHAR_ENA;
		break;
	case AB8500_GPADC_CHAN_BAT_TEMP:
		if (!is_ab8500_2p0_or_earlier(gpadc->ab8500)) {
			ctrl1 |= AB8500_GPADC_CTRL1_BUF_ENA |
				AB8500_GPADC_CTRL1_BTEMP_PULL_UP;
			/*
			 * Delay might be needed for ABB8500 cut 3.0, if not,
			 * remove when hardware will be available
			 */
			delay_min = 1000; /* Delay in micro seconds */
			delay_max = 10000; /* large range optimises sleepmode */
			break;
		}
		fallthrough;
	default:
		ctrl1 |= AB8500_GPADC_CTRL1_BUF_ENA;
		break;
	}

	/* Write configuration to control register 1 */
	ret = abx500_set_register_interruptible(gpadc->dev,
		AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ctrl1);
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: set Control register failed\n");
		goto out;
	}

	if (delay_min != 0)
		usleep_range(delay_min, delay_max);

	if (ch->hardware_control) {
		/* Set trigger delay timer */
		ret = abx500_set_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_AUTO_TIMER_REG,
			ch->trig_timer);
		if (ret < 0) {
			dev_err(gpadc->dev,
				"gpadc_conversion: trig timer failed\n");
			goto out;
		}
		completion_timeout = 2 * HZ;
		data_low_addr = AB8500_GPADC_AUTODATAL_REG;
		data_high_addr = AB8500_GPADC_AUTODATAH_REG;
	} else {
		/* Start SW conversion */
		ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
			AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
			AB8500_GPADC_CTRL1_START_SW_CONV,
			AB8500_GPADC_CTRL1_START_SW_CONV);
		if (ret < 0) {
			dev_err(gpadc->dev,
				"gpadc_conversion: start s/w conv failed\n");
			goto out;
		}
		completion_timeout = msecs_to_jiffies(AB8500_GPADC_CONVERSION_TIME);
		data_low_addr = AB8500_GPADC_MANDATAL_REG;
		data_high_addr = AB8500_GPADC_MANDATAH_REG;
	}

	/* Wait for completion of conversion */
	if (!wait_for_completion_timeout(&gpadc->complete,
			completion_timeout)) {
		dev_err(gpadc->dev,
			"timeout didn't receive GPADC conv interrupt\n");
		ret = -EINVAL;
		goto out;
	}

	/* Read the converted RAW data */
	ret = abx500_get_register_interruptible(gpadc->dev,
			AB8500_GPADC, data_low_addr, &low_data);
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: read low data failed\n");
		goto out;
	}

	ret = abx500_get_register_interruptible(gpadc->dev,
		AB8500_GPADC, data_high_addr, &high_data);
	if (ret < 0) {
		dev_err(gpadc->dev,
			"gpadc_conversion: read high data failed\n");
		goto out;
	}

	/* Check if double conversion is required */
	if ((ch->id == AB8500_GPADC_CHAN_BAT_CTRL_AND_IBAT) ||
	    (ch->id == AB8500_GPADC_CHAN_VBAT_MEAS_AND_IBAT) ||
	    (ch->id == AB8500_GPADC_CHAN_VBAT_TRUE_MEAS_AND_IBAT) ||
	    (ch->id == AB8500_GPADC_CHAN_BAT_TEMP_AND_IBAT)) {

		if (ch->hardware_control) {
			/* not supported */
			ret = -ENOTSUPP;
			dev_err(gpadc->dev,
				"gpadc_conversion: only SW double conversion supported\n");
			goto out;
		} else {
			/* Read the converted RAW data 2 */
			ret = abx500_get_register_interruptible(gpadc->dev,
				AB8500_GPADC, AB8540_GPADC_MANDATA2L_REG,
				&low_data2);
			if (ret < 0) {
				dev_err(gpadc->dev,
					"gpadc_conversion: read sw low data 2 failed\n");
				goto out;
			}

			ret = abx500_get_register_interruptible(gpadc->dev,
				AB8500_GPADC, AB8540_GPADC_MANDATA2H_REG,
				&high_data2);
			if (ret < 0) {
				dev_err(gpadc->dev,
					"gpadc_conversion: read sw high data 2 failed\n");
				goto out;
			}
			if (ibat != NULL) {
				*ibat = (high_data2 << 8) | low_data2;
			} else {
				dev_warn(gpadc->dev,
					"gpadc_conversion: ibat not stored\n");
			}

		}
	}

	/* Disable GPADC */
	ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_CTRL1_REG, AB8500_GPADC_CTRL1_DISABLE);
	if (ret < 0) {
		dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
		goto out;
	}

	/* This eventually drops the regulator */
	pm_runtime_mark_last_busy(gpadc->dev);
	pm_runtime_put_autosuspend(gpadc->dev);

	return (high_data << 8) | low_data;

out:
	/*
	 * It has shown to be needed to turn off the GPADC if an error occurs,
	 * otherwise we might have problem when waiting for the busy bit in the
	 * GPADC status register to go low. In V1.1 there wait_for_completion
	 * seems to timeout when waiting for an interrupt.. Not seen in V2.0
	 */
	(void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
		AB8500_GPADC_CTRL1_REG, AB8500_GPADC_CTRL1_DISABLE);
	pm_runtime_put(gpadc->dev);
	dev_err(gpadc->dev,
		"gpadc_conversion: Failed to AD convert channel %d\n", ch->id);

	return ret;
}

/**
 * ab8500_bm_gpadcconvend_handler() - isr for gpadc conversion completion
 * @irq: irq number
 * @data: pointer to the data passed during request irq
 *
 * This is a interrupt service routine for gpadc conversion completion.
 * Notifies the gpadc completion is completed and the converted raw value
 * can be read from the registers.
 * Returns IRQ status(IRQ_HANDLED)
 */
static irqreturn_t ab8500_bm_gpadcconvend_handler(int irq, void *data)
{
	struct ab8500_gpadc *gpadc = data;

	complete(&gpadc->complete);

	return IRQ_HANDLED;
}

static int otp_cal_regs[] = {
	AB8500_GPADC_CAL_1,
	AB8500_GPADC_CAL_2,
	AB8500_GPADC_CAL_3,
	AB8500_GPADC_CAL_4,
	AB8500_GPADC_CAL_5,
	AB8500_GPADC_CAL_6,
	AB8500_GPADC_CAL_7,
};

static int otp4_cal_regs[] = {
	AB8540_GPADC_OTP4_REG_7,
	AB8540_GPADC_OTP4_REG_6,
	AB8540_GPADC_OTP4_REG_5,
};

static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
{
	int i;
	int ret[ARRAY_SIZE(otp_cal_regs)];
	u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];
	int ret_otp4[ARRAY_SIZE(otp4_cal_regs)];
	u8 gpadc_otp4[ARRAY_SIZE(otp4_cal_regs)];
	int vmain_high, vmain_low;
	int btemp_high, btemp_low;
	int vbat_high, vbat_low;
	int ibat_high, ibat_low;
	s64 V_gain, V_offset, V2A_gain, V2A_offset;

	/* First we read all OTP registers and store the error code */
	for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
		ret[i] = abx500_get_register_interruptible(gpadc->dev,
			AB8500_OTP_EMUL, otp_cal_regs[i],  &gpadc_cal[i]);
		if (ret[i] < 0) {
			/* Continue anyway: maybe the other registers are OK */
			dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
				__func__, otp_cal_regs[i]);
		} else {
			/* Put this in the entropy pool as device-unique */
			add_device_randomness(&ret[i], sizeof(ret[i]));
		}
	}

	/*
	 * The ADC calibration data is stored in OTP registers.
	 * The layout of the calibration data is outlined below and a more
	 * detailed description can be found in UM0836
	 *
	 * vm_h/l = vmain_high/low
	 * bt_h/l = btemp_high/low
	 * vb_h/l = vbat_high/low
	 *
	 * Data bits 8500/9540:
	 * | 7	   | 6	   | 5	   | 4	   | 3	   | 2	   | 1	   | 0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |						   | vm_h9 | vm_h8
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |		   | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 *
	 * Data bits 8540:
	 * OTP2
	 * | 7	   | 6	   | 5	   | 4	   | 3	   | 2	   | 1	   | 0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vm_h9 | vm_h8 | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 *
	 * Data bits 8540:
	 * OTP4
	 * | 7	   | 6	   | 5	   | 4	   | 3	   | 2	   | 1	   | 0
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * |					   | ib_h9 | ib_h8 | ib_h7
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | ib_h6 | ib_h5 | ib_h4 | ib_h3 | ib_h2 | ib_h1 | ib_h0 | ib_l5
	 * |.......|.......|.......|.......|.......|.......|.......|.......
	 * | ib_l4 | ib_l3 | ib_l2 | ib_l1 | ib_l0 |
	 *
	 *
	 * Ideal output ADC codes corresponding to injected input voltages
	 * during manufacturing is:
	 *
	 * vmain_high: Vin = 19500mV / ADC ideal code = 997
	 * vmain_low:  Vin = 315mV   / ADC ideal code = 16
	 * btemp_high: Vin = 1300mV  / ADC ideal code = 985
	 * btemp_low:  Vin = 21mV    / ADC ideal code = 16
	 * vbat_high:  Vin = 4700mV  / ADC ideal code = 982
	 * vbat_low:   Vin = 2380mV  / ADC ideal code = 33
	 */

	if (is_ab8540(gpadc->ab8500)) {
		/* Calculate gain and offset for VMAIN if all reads succeeded*/
		if (!(ret[1] < 0 || ret[2] < 0)) {
			vmain_high = (((gpadc_cal[1] & 0xFF) << 2) |
				((gpadc_cal[2] & 0xC0) >> 6));
			vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);

			gpadc->cal_data[AB8500_CAL_VMAIN].otp_calib_hi =
				(u16)vmain_high;
			gpadc->cal_data[AB8500_CAL_VMAIN].otp_calib_lo =
				(u16)vmain_low;

			gpadc->cal_data[AB8500_CAL_VMAIN].gain = AB8500_GPADC_CALIB_SCALE *
				(19500 - 315) / (vmain_high - vmain_low);
			gpadc->cal_data[AB8500_CAL_VMAIN].offset = AB8500_GPADC_CALIB_SCALE *
				19500 - (AB8500_GPADC_CALIB_SCALE * (19500 - 315) /
				(vmain_high - vmain_low)) * vmain_high;
		} else {
			gpadc->cal_data[AB8500_CAL_VMAIN].gain = 0;
		}

		/* Read IBAT calibration Data */
		for (i = 0; i < ARRAY_SIZE(otp4_cal_regs); i++) {
			ret_otp4[i] = abx500_get_register_interruptible(
					gpadc->dev, AB8500_OTP_EMUL,
					otp4_cal_regs[i],  &gpadc_otp4[i]);
			if (ret_otp4[i] < 0)
				dev_err(gpadc->dev,
					"%s: read otp4 reg 0x%02x failed\n",
					__func__, otp4_cal_regs[i]);
		}

		/* Calculate gain and offset for IBAT if all reads succeeded */
		if (!(ret_otp4[0] < 0 || ret_otp4[1] < 0 || ret_otp4[2] < 0)) {
			ibat_high = (((gpadc_otp4[0] & 0x07) << 7) |
				((gpadc_otp4[1] & 0xFE) >> 1));
			ibat_low = (((gpadc_otp4[1] & 0x01) << 5) |
				((gpadc_otp4[2] & 0xF8) >> 3));

			gpadc->cal_data[AB8500_CAL_IBAT].otp_calib_hi =
				(u16)ibat_high;
			gpadc->cal_data[AB8500_CAL_IBAT].otp_calib_lo =
				(u16)ibat_low;

			V_gain = ((AB8500_GPADC_IBAT_VDROP_H - AB8500_GPADC_IBAT_VDROP_L)
				<< AB8500_GPADC_CALIB_SHIFT_IBAT) / (ibat_high - ibat_low);

			V_offset = (AB8500_GPADC_IBAT_VDROP_H << AB8500_GPADC_CALIB_SHIFT_IBAT) -
				(((AB8500_GPADC_IBAT_VDROP_H - AB8500_GPADC_IBAT_VDROP_L) <<
				AB8500_GPADC_CALIB_SHIFT_IBAT) / (ibat_high - ibat_low))
				* ibat_high;
			/*
			 * Result obtained is in mV (at a scale factor),
			 * we need to calculate gain and offset to get mA
			 */
			V2A_gain = (AB8500_ADC_CH_IBAT_MAX - AB8500_ADC_CH_IBAT_MIN)/
				(AB8500_ADC_CH_IBAT_MAX_V - AB8500_ADC_CH_IBAT_MIN_V);
			V2A_offset = ((AB8500_ADC_CH_IBAT_MAX_V * AB8500_ADC_CH_IBAT_MIN -
				AB8500_ADC_CH_IBAT_MAX * AB8500_ADC_CH_IBAT_MIN_V)
				<< AB8500_GPADC_CALIB_SHIFT_IBAT)
				/ (AB8500_ADC_CH_IBAT_MAX_V - AB8500_ADC_CH_IBAT_MIN_V);

			gpadc->cal_data[AB8500_CAL_IBAT].gain =
				V_gain * V2A_gain;
			gpadc->cal_data[AB8500_CAL_IBAT].offset =
				V_offset * V2A_gain + V2A_offset;
		} else {
			gpadc->cal_data[AB8500_CAL_IBAT].gain = 0;
		}
	} else {
		/* Calculate gain and offset for VMAIN if all reads succeeded */
		if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
			vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
				((gpadc_cal[1] & 0x3F) << 2) |
				((gpadc_cal[2] & 0xC0) >> 6));
			vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);

			gpadc->cal_data[AB8500_CAL_VMAIN].otp_calib_hi =
				(u16)vmain_high;
			gpadc->cal_data[AB8500_CAL_VMAIN].otp_calib_lo =
				(u16)vmain_low;

			gpadc->cal_data[AB8500_CAL_VMAIN].gain = AB8500_GPADC_CALIB_SCALE *
				(19500 - 315) / (vmain_high - vmain_low);

			gpadc->cal_data[AB8500_CAL_VMAIN].offset = AB8500_GPADC_CALIB_SCALE *
				19500 - (AB8500_GPADC_CALIB_SCALE * (19500 - 315) /
				(vmain_high - vmain_low)) * vmain_high;
		} else {
			gpadc->cal_data[AB8500_CAL_VMAIN].gain = 0;
		}
	}

	/* Calculate gain and offset for BTEMP if all reads succeeded */
	if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
		btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
			(gpadc_cal[3] << 1) | ((gpadc_cal[4] & 0x80) >> 7));
		btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);

		gpadc->cal_data[AB8500_CAL_BTEMP].otp_calib_hi = (u16)btemp_high;
		gpadc->cal_data[AB8500_CAL_BTEMP].otp_calib_lo = (u16)btemp_low;

		gpadc->cal_data[AB8500_CAL_BTEMP].gain =
			AB8500_GPADC_CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);
		gpadc->cal_data[AB8500_CAL_BTEMP].offset = AB8500_GPADC_CALIB_SCALE * 1300 -
			(AB8500_GPADC_CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low))
			* btemp_high;
	} else {
		gpadc->cal_data[AB8500_CAL_BTEMP].gain = 0;
	}

	/* Calculate gain and offset for VBAT if all reads succeeded */
	if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
		vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
		vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);

		gpadc->cal_data[AB8500_CAL_VBAT].otp_calib_hi = (u16)vbat_high;
		gpadc->cal_data[AB8500_CAL_VBAT].otp_calib_lo = (u16)vbat_low;

		gpadc->cal_data[AB8500_CAL_VBAT].gain = AB8500_GPADC_CALIB_SCALE *
			(4700 - 2380) /	(vbat_high - vbat_low);
		gpadc->cal_data[AB8500_CAL_VBAT].offset = AB8500_GPADC_CALIB_SCALE * 4700 -
			(AB8500_GPADC_CALIB_SCALE * (4700 - 2380) /
			(vbat_high - vbat_low)) * vbat_high;
	} else {
		gpadc->cal_data[AB8500_CAL_VBAT].gain = 0;
	}
}

static int ab8500_gpadc_read_raw(struct iio_dev *indio_dev,
				 struct iio_chan_spec const *chan,
				 int *val, int *val2, long mask)
{
	struct ab8500_gpadc *gpadc = iio_priv(indio_dev);
	const struct ab8500_gpadc_chan_info *ch;
	int raw_val;
	int processed;

	ch = ab8500_gpadc_get_channel(gpadc, chan->address);
	if (!ch) {
		dev_err(gpadc->dev, "no such channel %lu\n",
			chan->address);
		return -EINVAL;
	}

	raw_val = ab8500_gpadc_read(gpadc, ch, NULL);
	if (raw_val < 0)
		return raw_val;

	if (mask == IIO_CHAN_INFO_RAW) {
		*val = raw_val;
		return IIO_VAL_INT;
	}

	if (mask == IIO_CHAN_INFO_PROCESSED) {
		processed = ab8500_gpadc_ad_to_voltage(gpadc, ch->id, raw_val);
		if (processed < 0)
			return processed;

		/* Return millivolt or milliamps or millicentigrades */
		*val = processed;
		return IIO_VAL_INT;
	}

	return -EINVAL;
}

static int ab8500_gpadc_fwnode_xlate(struct iio_dev *indio_dev,
				     const struct fwnode_reference_args *iiospec)
{
	int i;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].channel == iiospec->args[0])
			return i;

	return -EINVAL;
}

static const struct iio_info ab8500_gpadc_info = {
	.fwnode_xlate = ab8500_gpadc_fwnode_xlate,
	.read_raw = ab8500_gpadc_read_raw,
};

static int ab8500_gpadc_runtime_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct ab8500_gpadc *gpadc = iio_priv(indio_dev);

	regulator_disable(gpadc->vddadc);

	return 0;
}

static int ab8500_gpadc_runtime_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct ab8500_gpadc *gpadc = iio_priv(indio_dev);
	int ret;

	ret = regulator_enable(gpadc->vddadc);
	if (ret)
		dev_err(dev, "Failed to enable vddadc: %d\n", ret);

	return ret;
}

/**
 * ab8500_gpadc_parse_channel() - process devicetree channel configuration
 * @dev: pointer to containing device
 * @fwnode: fw node for the channel to configure
 * @ch: channel info to fill in
 * @iio_chan: IIO channel specification to fill in
 *
 * The devicetree will set up the channel for use with the specific device,
 * and define usage for things like AUX GPADC inputs more precisely.
 */
static int ab8500_gpadc_parse_channel(struct device *dev,
				      struct fwnode_handle *fwnode,
				      struct ab8500_gpadc_chan_info *ch,
				      struct iio_chan_spec *iio_chan)
{
	const char *name = fwnode_get_name(fwnode);
	u32 chan;
	int ret;

	ret = fwnode_property_read_u32(fwnode, "reg", &chan);
	if (ret) {
		dev_err(dev, "invalid channel number %s\n", name);
		return ret;
	}
	if (chan > AB8500_GPADC_CHAN_BAT_TEMP_AND_IBAT) {
		dev_err(dev, "%s channel number out of range %d\n", name, chan);
		return -EINVAL;
	}

	iio_chan->channel = chan;
	iio_chan->datasheet_name = name;
	iio_chan->indexed = 1;
	iio_chan->address = chan;
	iio_chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
		BIT(IIO_CHAN_INFO_PROCESSED);
	/* Most are voltages (also temperatures), some are currents */
	if ((chan == AB8500_GPADC_CHAN_MAIN_CHARGER_CURRENT) ||
	    (chan == AB8500_GPADC_CHAN_USB_CHARGER_CURRENT))
		iio_chan->type = IIO_CURRENT;
	else
		iio_chan->type = IIO_VOLTAGE;

	ch->id = chan;

	/* Sensible defaults */
	ch->avg_sample = 16;
	ch->hardware_control = false;
	ch->falling_edge = false;
	ch->trig_timer = 0;

	return 0;
}

/**
 * ab8500_gpadc_parse_channels() - Parse the GPADC channels from DT
 * @gpadc: the GPADC to configure the channels for
 * @chans: the IIO channels we parsed
 * @nchans: the number of IIO channels we parsed
 */
static int ab8500_gpadc_parse_channels(struct ab8500_gpadc *gpadc,
				       struct iio_chan_spec **chans_parsed,
				       unsigned int *nchans_parsed)
{
	struct fwnode_handle *child;
	struct ab8500_gpadc_chan_info *ch;
	struct iio_chan_spec *iio_chans;
	unsigned int nchans;
	int i;

	nchans = device_get_child_node_count(gpadc->dev);
	if (!nchans) {
		dev_err(gpadc->dev, "no channel children\n");
		return -ENODEV;
	}
	dev_info(gpadc->dev, "found %d ADC channels\n", nchans);

	iio_chans = devm_kcalloc(gpadc->dev, nchans,
				 sizeof(*iio_chans), GFP_KERNEL);
	if (!iio_chans)
		return -ENOMEM;

	gpadc->chans = devm_kcalloc(gpadc->dev, nchans,
				    sizeof(*gpadc->chans), GFP_KERNEL);
	if (!gpadc->chans)
		return -ENOMEM;

	i = 0;
	device_for_each_child_node(gpadc->dev, child) {
		struct iio_chan_spec *iio_chan;
		int ret;

		ch = &gpadc->chans[i];
		iio_chan = &iio_chans[i];

		ret = ab8500_gpadc_parse_channel(gpadc->dev, child, ch,
						 iio_chan);
		if (ret) {
			fwnode_handle_put(child);
			return ret;
		}
		i++;
	}
	gpadc->nchans = nchans;
	*chans_parsed = iio_chans;
	*nchans_parsed = nchans;

	return 0;
}

static int ab8500_gpadc_probe(struct platform_device *pdev)
{
	struct ab8500_gpadc *gpadc;
	struct iio_dev *indio_dev;
	struct device *dev = &pdev->dev;
	struct iio_chan_spec *iio_chans;
	unsigned int n_iio_chans;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*gpadc));
	if (!indio_dev)
		return -ENOMEM;

	platform_set_drvdata(pdev, indio_dev);
	gpadc = iio_priv(indio_dev);

	gpadc->dev = dev;
	gpadc->ab8500 = dev_get_drvdata(dev->parent);

	ret = ab8500_gpadc_parse_channels(gpadc, &iio_chans, &n_iio_chans);
	if (ret)
		return ret;

	gpadc->irq_sw = platform_get_irq_byname(pdev, "SW_CONV_END");
	if (gpadc->irq_sw < 0)
		return gpadc->irq_sw;

	if (is_ab8500(gpadc->ab8500)) {
		gpadc->irq_hw = platform_get_irq_byname(pdev, "HW_CONV_END");
		if (gpadc->irq_hw < 0)
			return gpadc->irq_hw;
	} else {
		gpadc->irq_hw = 0;
	}

	/* Initialize completion used to notify completion of conversion */
	init_completion(&gpadc->complete);

	/* Request interrupts */
	ret = devm_request_threaded_irq(dev, gpadc->irq_sw, NULL,
		ab8500_bm_gpadcconvend_handler,	IRQF_NO_SUSPEND | IRQF_ONESHOT,
		"ab8500-gpadc-sw", gpadc);
	if (ret < 0) {
		dev_err(dev,
			"failed to request sw conversion irq %d\n",
			gpadc->irq_sw);
		return ret;
	}

	if (gpadc->irq_hw) {
		ret = devm_request_threaded_irq(dev, gpadc->irq_hw, NULL,
			ab8500_bm_gpadcconvend_handler,	IRQF_NO_SUSPEND | IRQF_ONESHOT,
			"ab8500-gpadc-hw", gpadc);
		if (ret < 0) {
			dev_err(dev,
				"Failed to request hw conversion irq: %d\n",
				gpadc->irq_hw);
			return ret;
		}
	}

	/* The VTVout LDO used to power the AB8500 GPADC */
	gpadc->vddadc = devm_regulator_get(dev, "vddadc");
	if (IS_ERR(gpadc->vddadc))
		return dev_err_probe(dev, PTR_ERR(gpadc->vddadc),
				     "failed to get vddadc\n");

	ret = regulator_enable(gpadc->vddadc);
	if (ret) {
		dev_err(dev, "failed to enable vddadc: %d\n", ret);
		return ret;
	}

	/* Enable runtime PM */
	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	pm_runtime_set_autosuspend_delay(dev, AB8500_GPADC_AUTOSUSPEND_DELAY);
	pm_runtime_use_autosuspend(dev);

	ab8500_gpadc_read_calibration_data(gpadc);

	pm_runtime_put(dev);

	indio_dev->name = "ab8500-gpadc";
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &ab8500_gpadc_info;
	indio_dev->channels = iio_chans;
	indio_dev->num_channels = n_iio_chans;

	ret = devm_iio_device_register(dev, indio_dev);
	if (ret)
		goto out_dis_pm;

	return 0;

out_dis_pm:
	pm_runtime_get_sync(dev);
	pm_runtime_put_noidle(dev);
	pm_runtime_disable(dev);
	regulator_disable(gpadc->vddadc);

	return ret;
}

static int ab8500_gpadc_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct ab8500_gpadc *gpadc = iio_priv(indio_dev);

	pm_runtime_get_sync(gpadc->dev);
	pm_runtime_put_noidle(gpadc->dev);
	pm_runtime_disable(gpadc->dev);
	regulator_disable(gpadc->vddadc);

	return 0;
}

static DEFINE_RUNTIME_DEV_PM_OPS(ab8500_gpadc_pm_ops,
				 ab8500_gpadc_runtime_suspend,
				 ab8500_gpadc_runtime_resume, NULL);

static struct platform_driver ab8500_gpadc_driver = {
	.probe = ab8500_gpadc_probe,
	.remove = ab8500_gpadc_remove,
	.driver = {
		.name = "ab8500-gpadc",
		.pm = pm_ptr(&ab8500_gpadc_pm_ops),
	},
};
builtin_platform_driver(ab8500_gpadc_driver);