summaryrefslogtreecommitdiff
path: root/drivers/iio/magnetometer/bmc150_magn.c
blob: 074a99da7367305d2beb09503192a992e462b822 (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
/*
 * Bosch BMC150 three-axis magnetic field sensor driver
 *
 * Copyright (c) 2015, Intel Corporation.
 *
 * This code is based on bmm050_api.c authored by contact@bosch.sensortec.com:
 *
 * (C) Copyright 2011~2014 Bosch Sensortec GmbH All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/regmap.h>

#define BMC150_MAGN_DRV_NAME			"bmc150_magn"
#define BMC150_MAGN_IRQ_NAME			"bmc150_magn_event"
#define BMC150_MAGN_GPIO_INT			"interrupt"

#define BMC150_MAGN_REG_CHIP_ID			0x40
#define BMC150_MAGN_CHIP_ID_VAL			0x32

#define BMC150_MAGN_REG_X_L			0x42
#define BMC150_MAGN_REG_X_M			0x43
#define BMC150_MAGN_REG_Y_L			0x44
#define BMC150_MAGN_REG_Y_M			0x45
#define BMC150_MAGN_SHIFT_XY_L			3
#define BMC150_MAGN_REG_Z_L			0x46
#define BMC150_MAGN_REG_Z_M			0x47
#define BMC150_MAGN_SHIFT_Z_L			1
#define BMC150_MAGN_REG_RHALL_L			0x48
#define BMC150_MAGN_REG_RHALL_M			0x49
#define BMC150_MAGN_SHIFT_RHALL_L		2

#define BMC150_MAGN_REG_INT_STATUS		0x4A

#define BMC150_MAGN_REG_POWER			0x4B
#define BMC150_MAGN_MASK_POWER_CTL		BIT(0)

#define BMC150_MAGN_REG_OPMODE_ODR		0x4C
#define BMC150_MAGN_MASK_OPMODE			GENMASK(2, 1)
#define BMC150_MAGN_SHIFT_OPMODE		1
#define BMC150_MAGN_MODE_NORMAL			0x00
#define BMC150_MAGN_MODE_FORCED			0x01
#define BMC150_MAGN_MODE_SLEEP			0x03
#define BMC150_MAGN_MASK_ODR			GENMASK(5, 3)
#define BMC150_MAGN_SHIFT_ODR			3

#define BMC150_MAGN_REG_INT			0x4D

#define BMC150_MAGN_REG_INT_DRDY		0x4E
#define BMC150_MAGN_MASK_DRDY_EN		BIT(7)
#define BMC150_MAGN_SHIFT_DRDY_EN		7
#define BMC150_MAGN_MASK_DRDY_INT3		BIT(6)
#define BMC150_MAGN_MASK_DRDY_Z_EN		BIT(5)
#define BMC150_MAGN_MASK_DRDY_Y_EN		BIT(4)
#define BMC150_MAGN_MASK_DRDY_X_EN		BIT(3)
#define BMC150_MAGN_MASK_DRDY_DR_POLARITY	BIT(2)
#define BMC150_MAGN_MASK_DRDY_LATCHING		BIT(1)
#define BMC150_MAGN_MASK_DRDY_INT3_POLARITY	BIT(0)

#define BMC150_MAGN_REG_LOW_THRESH		0x4F
#define BMC150_MAGN_REG_HIGH_THRESH		0x50
#define BMC150_MAGN_REG_REP_XY			0x51
#define BMC150_MAGN_REG_REP_Z			0x52

#define BMC150_MAGN_REG_TRIM_START		0x5D
#define BMC150_MAGN_REG_TRIM_END		0x71

#define BMC150_MAGN_XY_OVERFLOW_VAL		-4096
#define BMC150_MAGN_Z_OVERFLOW_VAL		-16384

/* Time from SUSPEND to SLEEP */
#define BMC150_MAGN_START_UP_TIME_MS		3

#define BMC150_MAGN_AUTO_SUSPEND_DELAY_MS	2000

#define BMC150_MAGN_REGVAL_TO_REPXY(regval) (((regval) * 2) + 1)
#define BMC150_MAGN_REGVAL_TO_REPZ(regval) ((regval) + 1)
#define BMC150_MAGN_REPXY_TO_REGVAL(rep) (((rep) - 1) / 2)
#define BMC150_MAGN_REPZ_TO_REGVAL(rep) ((rep) - 1)

enum bmc150_magn_axis {
	AXIS_X,
	AXIS_Y,
	AXIS_Z,
	RHALL,
	AXIS_XYZ_MAX = RHALL,
	AXIS_XYZR_MAX,
};

enum bmc150_magn_power_modes {
	BMC150_MAGN_POWER_MODE_SUSPEND,
	BMC150_MAGN_POWER_MODE_SLEEP,
	BMC150_MAGN_POWER_MODE_NORMAL,
};

struct bmc150_magn_trim_regs {
	s8 x1;
	s8 y1;
	__le16 reserved1;
	u8 reserved2;
	__le16 z4;
	s8 x2;
	s8 y2;
	__le16 reserved3;
	__le16 z2;
	__le16 z1;
	__le16 xyz1;
	__le16 z3;
	s8 xy2;
	u8 xy1;
} __packed;

struct bmc150_magn_data {
	struct i2c_client *client;
	/*
	 * 1. Protect this structure.
	 * 2. Serialize sequences that power on/off the device and access HW.
	 */
	struct mutex mutex;
	struct regmap *regmap;
	/* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
	s32 buffer[6];
	struct iio_trigger *dready_trig;
	bool dready_trigger_on;
	int max_odr;
};

static const struct {
	int freq;
	u8 reg_val;
} bmc150_magn_samp_freq_table[] = { {2, 0x01},
				    {6, 0x02},
				    {8, 0x03},
				    {10, 0x00},
				    {15, 0x04},
				    {20, 0x05},
				    {25, 0x06},
				    {30, 0x07} };

enum bmc150_magn_presets {
	LOW_POWER_PRESET,
	REGULAR_PRESET,
	ENHANCED_REGULAR_PRESET,
	HIGH_ACCURACY_PRESET
};

static const struct bmc150_magn_preset {
	u8 rep_xy;
	u8 rep_z;
	u8 odr;
} bmc150_magn_presets_table[] = {
	[LOW_POWER_PRESET] = {3, 3, 10},
	[REGULAR_PRESET] =  {9, 15, 10},
	[ENHANCED_REGULAR_PRESET] =  {15, 27, 10},
	[HIGH_ACCURACY_PRESET] =  {47, 83, 20},
};

#define BMC150_MAGN_DEFAULT_PRESET REGULAR_PRESET

static bool bmc150_magn_is_writeable_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case BMC150_MAGN_REG_POWER:
	case BMC150_MAGN_REG_OPMODE_ODR:
	case BMC150_MAGN_REG_INT:
	case BMC150_MAGN_REG_INT_DRDY:
	case BMC150_MAGN_REG_LOW_THRESH:
	case BMC150_MAGN_REG_HIGH_THRESH:
	case BMC150_MAGN_REG_REP_XY:
	case BMC150_MAGN_REG_REP_Z:
		return true;
	default:
		return false;
	};
}

static bool bmc150_magn_is_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case BMC150_MAGN_REG_X_L:
	case BMC150_MAGN_REG_X_M:
	case BMC150_MAGN_REG_Y_L:
	case BMC150_MAGN_REG_Y_M:
	case BMC150_MAGN_REG_Z_L:
	case BMC150_MAGN_REG_Z_M:
	case BMC150_MAGN_REG_RHALL_L:
	case BMC150_MAGN_REG_RHALL_M:
	case BMC150_MAGN_REG_INT_STATUS:
		return true;
	default:
		return false;
	}
}

static const struct regmap_config bmc150_magn_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = BMC150_MAGN_REG_TRIM_END,
	.cache_type = REGCACHE_RBTREE,

	.writeable_reg = bmc150_magn_is_writeable_reg,
	.volatile_reg = bmc150_magn_is_volatile_reg,
};

static int bmc150_magn_set_power_mode(struct bmc150_magn_data *data,
				      enum bmc150_magn_power_modes mode,
				      bool state)
{
	int ret;

	switch (mode) {
	case BMC150_MAGN_POWER_MODE_SUSPEND:
		ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_POWER,
					 BMC150_MAGN_MASK_POWER_CTL, !state);
		if (ret < 0)
			return ret;
		usleep_range(BMC150_MAGN_START_UP_TIME_MS * 1000, 20000);
		return 0;
	case BMC150_MAGN_POWER_MODE_SLEEP:
		return regmap_update_bits(data->regmap,
					  BMC150_MAGN_REG_OPMODE_ODR,
					  BMC150_MAGN_MASK_OPMODE,
					  BMC150_MAGN_MODE_SLEEP <<
					  BMC150_MAGN_SHIFT_OPMODE);
	case BMC150_MAGN_POWER_MODE_NORMAL:
		return regmap_update_bits(data->regmap,
					  BMC150_MAGN_REG_OPMODE_ODR,
					  BMC150_MAGN_MASK_OPMODE,
					  BMC150_MAGN_MODE_NORMAL <<
					  BMC150_MAGN_SHIFT_OPMODE);
	}

	return -EINVAL;
}

static int bmc150_magn_set_power_state(struct bmc150_magn_data *data, bool on)
{
#ifdef CONFIG_PM
	int ret;

	if (on) {
		ret = pm_runtime_get_sync(&data->client->dev);
	} else {
		pm_runtime_mark_last_busy(&data->client->dev);
		ret = pm_runtime_put_autosuspend(&data->client->dev);
	}

	if (ret < 0) {
		dev_err(&data->client->dev,
			"failed to change power state to %d\n", on);
		if (on)
			pm_runtime_put_noidle(&data->client->dev);

		return ret;
	}
#endif

	return 0;
}

static int bmc150_magn_get_odr(struct bmc150_magn_data *data, int *val)
{
	int ret, reg_val;
	u8 i, odr_val;

	ret = regmap_read(data->regmap, BMC150_MAGN_REG_OPMODE_ODR, &reg_val);
	if (ret < 0)
		return ret;
	odr_val = (reg_val & BMC150_MAGN_MASK_ODR) >> BMC150_MAGN_SHIFT_ODR;

	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++)
		if (bmc150_magn_samp_freq_table[i].reg_val == odr_val) {
			*val = bmc150_magn_samp_freq_table[i].freq;
			return 0;
		}

	return -EINVAL;
}

static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val)
{
	int ret;
	u8 i;

	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
		if (bmc150_magn_samp_freq_table[i].freq == val) {
			ret = regmap_update_bits(data->regmap,
						 BMC150_MAGN_REG_OPMODE_ODR,
						 BMC150_MAGN_MASK_ODR,
						 bmc150_magn_samp_freq_table[i].
						 reg_val <<
						 BMC150_MAGN_SHIFT_ODR);
			if (ret < 0)
				return ret;
			return 0;
		}
	}

	return -EINVAL;
}

static int bmc150_magn_set_max_odr(struct bmc150_magn_data *data, int rep_xy,
				   int rep_z, int odr)
{
	int ret, reg_val, max_odr;

	if (rep_xy <= 0) {
		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
				  &reg_val);
		if (ret < 0)
			return ret;
		rep_xy = BMC150_MAGN_REGVAL_TO_REPXY(reg_val);
	}
	if (rep_z <= 0) {
		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
				  &reg_val);
		if (ret < 0)
			return ret;
		rep_z = BMC150_MAGN_REGVAL_TO_REPZ(reg_val);
	}
	if (odr <= 0) {
		ret = bmc150_magn_get_odr(data, &odr);
		if (ret < 0)
			return ret;
	}
	/* the maximum selectable read-out frequency from datasheet */
	max_odr = 1000000 / (145 * rep_xy + 500 * rep_z + 980);
	if (odr > max_odr) {
		dev_err(&data->client->dev,
			"Can't set oversampling with sampling freq %d\n",
			odr);
		return -EINVAL;
	}
	data->max_odr = max_odr;

	return 0;
}

static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,
				    u16 rhall)
{
	s16 val;
	u16 xyz1 = le16_to_cpu(tregs->xyz1);

	if (x == BMC150_MAGN_XY_OVERFLOW_VAL)
		return S32_MIN;

	if (!rhall)
		rhall = xyz1;

	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
	val = ((s16)((((s32)x) * ((((((((s32)tregs->xy2) * ((((s32)val) *
	      ((s32)val)) >> 7)) + (((s32)val) *
	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
	      ((s32)(((s16)tregs->x2) + ((s16)0xA0)))) >> 12)) >> 13)) +
	      (((s16)tregs->x1) << 3);

	return (s32)val;
}

static s32 bmc150_magn_compensate_y(struct bmc150_magn_trim_regs *tregs, s16 y,
				    u16 rhall)
{
	s16 val;
	u16 xyz1 = le16_to_cpu(tregs->xyz1);

	if (y == BMC150_MAGN_XY_OVERFLOW_VAL)
		return S32_MIN;

	if (!rhall)
		rhall = xyz1;

	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
	val = ((s16)((((s32)y) * ((((((((s32)tregs->xy2) * ((((s32)val) *
	      ((s32)val)) >> 7)) + (((s32)val) *
	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
	      ((s32)(((s16)tregs->y2) + ((s16)0xA0)))) >> 12)) >> 13)) +
	      (((s16)tregs->y1) << 3);

	return (s32)val;
}

static s32 bmc150_magn_compensate_z(struct bmc150_magn_trim_regs *tregs, s16 z,
				    u16 rhall)
{
	s32 val;
	u16 xyz1 = le16_to_cpu(tregs->xyz1);
	u16 z1 = le16_to_cpu(tregs->z1);
	s16 z2 = le16_to_cpu(tregs->z2);
	s16 z3 = le16_to_cpu(tregs->z3);
	s16 z4 = le16_to_cpu(tregs->z4);

	if (z == BMC150_MAGN_Z_OVERFLOW_VAL)
		return S32_MIN;

	val = (((((s32)(z - z4)) << 15) - ((((s32)z3) * ((s32)(((s16)rhall) -
	      ((s16)xyz1)))) >> 2)) / (z2 + ((s16)(((((s32)z1) *
	      ((((s16)rhall) << 1))) + (1 << 15)) >> 16))));

	return val;
}

static int bmc150_magn_read_xyz(struct bmc150_magn_data *data, s32 *buffer)
{
	int ret;
	__le16 values[AXIS_XYZR_MAX];
	s16 raw_x, raw_y, raw_z;
	u16 rhall;
	struct bmc150_magn_trim_regs tregs;

	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_X_L,
			       values, sizeof(values));
	if (ret < 0)
		return ret;

	raw_x = (s16)le16_to_cpu(values[AXIS_X]) >> BMC150_MAGN_SHIFT_XY_L;
	raw_y = (s16)le16_to_cpu(values[AXIS_Y]) >> BMC150_MAGN_SHIFT_XY_L;
	raw_z = (s16)le16_to_cpu(values[AXIS_Z]) >> BMC150_MAGN_SHIFT_Z_L;
	rhall = le16_to_cpu(values[RHALL]) >> BMC150_MAGN_SHIFT_RHALL_L;

	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_TRIM_START,
			       &tregs, sizeof(tregs));
	if (ret < 0)
		return ret;

	buffer[AXIS_X] = bmc150_magn_compensate_x(&tregs, raw_x, rhall);
	buffer[AXIS_Y] = bmc150_magn_compensate_y(&tregs, raw_y, rhall);
	buffer[AXIS_Z] = bmc150_magn_compensate_z(&tregs, raw_z, rhall);

	return 0;
}

static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret, tmp;
	s32 values[AXIS_XYZ_MAX];

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (iio_buffer_enabled(indio_dev))
			return -EBUSY;
		mutex_lock(&data->mutex);

		ret = bmc150_magn_set_power_state(data, true);
		if (ret < 0) {
			mutex_unlock(&data->mutex);
			return ret;
		}

		ret = bmc150_magn_read_xyz(data, values);
		if (ret < 0) {
			bmc150_magn_set_power_state(data, false);
			mutex_unlock(&data->mutex);
			return ret;
		}
		*val = values[chan->scan_index];

		ret = bmc150_magn_set_power_state(data, false);
		if (ret < 0) {
			mutex_unlock(&data->mutex);
			return ret;
		}

		mutex_unlock(&data->mutex);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		/*
		 * The API/driver performs an off-chip temperature
		 * compensation and outputs x/y/z magnetic field data in
		 * 16 LSB/uT to the upper application layer.
		 */
		*val = 0;
		*val2 = 625;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_SAMP_FREQ:
		ret = bmc150_magn_get_odr(data, val);
		if (ret < 0)
			return ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		switch (chan->channel2) {
		case IIO_MOD_X:
		case IIO_MOD_Y:
			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
					  &tmp);
			if (ret < 0)
				return ret;
			*val = BMC150_MAGN_REGVAL_TO_REPXY(tmp);
			return IIO_VAL_INT;
		case IIO_MOD_Z:
			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
					  &tmp);
			if (ret < 0)
				return ret;
			*val = BMC150_MAGN_REGVAL_TO_REPZ(tmp);
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
				 struct iio_chan_spec const *chan,
				 int val, int val2, long mask)
{
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		if (val > data->max_odr)
			return -EINVAL;
		mutex_lock(&data->mutex);
		ret = bmc150_magn_set_odr(data, val);
		mutex_unlock(&data->mutex);
		return ret;
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		switch (chan->channel2) {
		case IIO_MOD_X:
		case IIO_MOD_Y:
			if (val < 1 || val > 511)
				return -EINVAL;
			mutex_lock(&data->mutex);
			ret = bmc150_magn_set_max_odr(data, val, 0, 0);
			if (ret < 0) {
				mutex_unlock(&data->mutex);
				return ret;
			}
			ret = regmap_update_bits(data->regmap,
						 BMC150_MAGN_REG_REP_XY,
						 0xFF,
						 BMC150_MAGN_REPXY_TO_REGVAL
						 (val));
			mutex_unlock(&data->mutex);
			return ret;
		case IIO_MOD_Z:
			if (val < 1 || val > 256)
				return -EINVAL;
			mutex_lock(&data->mutex);
			ret = bmc150_magn_set_max_odr(data, 0, val, 0);
			if (ret < 0) {
				mutex_unlock(&data->mutex);
				return ret;
			}
			ret = regmap_update_bits(data->regmap,
						 BMC150_MAGN_REG_REP_Z,
						 0xFF,
						 BMC150_MAGN_REPZ_TO_REGVAL
						 (val));
			mutex_unlock(&data->mutex);
			return ret;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static ssize_t bmc150_magn_show_samp_freq_avail(struct device *dev,
						struct device_attribute *attr,
						char *buf)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	size_t len = 0;
	u8 i;

	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
		if (bmc150_magn_samp_freq_table[i].freq > data->max_odr)
			break;
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
				 bmc150_magn_samp_freq_table[i].freq);
	}
	/* replace last space with a newline */
	buf[len - 1] = '\n';

	return len;
}

static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(bmc150_magn_show_samp_freq_avail);

static struct attribute *bmc150_magn_attributes[] = {
	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group bmc150_magn_attrs_group = {
	.attrs = bmc150_magn_attributes,
};

#define BMC150_MAGN_CHANNEL(_axis) {					\
	.type = IIO_MAGN,						\
	.modified = 1,							\
	.channel2 = IIO_MOD_##_axis,					\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
			      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\
				    BIT(IIO_CHAN_INFO_SCALE),		\
	.scan_index = AXIS_##_axis,					\
	.scan_type = {							\
		.sign = 's',						\
		.realbits = 32,						\
		.storagebits = 32,					\
		.endianness = IIO_LE					\
	},								\
}

static const struct iio_chan_spec bmc150_magn_channels[] = {
	BMC150_MAGN_CHANNEL(X),
	BMC150_MAGN_CHANNEL(Y),
	BMC150_MAGN_CHANNEL(Z),
	IIO_CHAN_SOFT_TIMESTAMP(3),
};

static const struct iio_info bmc150_magn_info = {
	.attrs = &bmc150_magn_attrs_group,
	.read_raw = bmc150_magn_read_raw,
	.write_raw = bmc150_magn_write_raw,
	.driver_module = THIS_MODULE,
};

static const unsigned long bmc150_magn_scan_masks[] = {
					BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
					0};

static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bmc150_magn_read_xyz(data, data->buffer);
	mutex_unlock(&data->mutex);
	if (ret < 0)
		goto err;

	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
					   pf->timestamp);

err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static int bmc150_magn_init(struct bmc150_magn_data *data)
{
	int ret, chip_id;
	struct bmc150_magn_preset preset;

	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND,
					 false);
	if (ret < 0) {
		dev_err(&data->client->dev,
			"Failed to bring up device from suspend mode\n");
		return ret;
	}

	ret = regmap_read(data->regmap, BMC150_MAGN_REG_CHIP_ID, &chip_id);
	if (ret < 0) {
		dev_err(&data->client->dev, "Failed reading chip id\n");
		goto err_poweroff;
	}
	if (chip_id != BMC150_MAGN_CHIP_ID_VAL) {
		dev_err(&data->client->dev, "Invalid chip id 0x%x\n", ret);
		ret = -ENODEV;
		goto err_poweroff;
	}
	dev_dbg(&data->client->dev, "Chip id %x\n", ret);

	preset = bmc150_magn_presets_table[BMC150_MAGN_DEFAULT_PRESET];
	ret = bmc150_magn_set_odr(data, preset.odr);
	if (ret < 0) {
		dev_err(&data->client->dev, "Failed to set ODR to %d\n",
			preset.odr);
		goto err_poweroff;
	}

	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_XY,
			   BMC150_MAGN_REPXY_TO_REGVAL(preset.rep_xy));
	if (ret < 0) {
		dev_err(&data->client->dev, "Failed to set REP XY to %d\n",
			preset.rep_xy);
		goto err_poweroff;
	}

	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_Z,
			   BMC150_MAGN_REPZ_TO_REGVAL(preset.rep_z));
	if (ret < 0) {
		dev_err(&data->client->dev, "Failed to set REP Z to %d\n",
			preset.rep_z);
		goto err_poweroff;
	}

	ret = bmc150_magn_set_max_odr(data, preset.rep_xy, preset.rep_z,
				      preset.odr);
	if (ret < 0)
		goto err_poweroff;

	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
					 true);
	if (ret < 0) {
		dev_err(&data->client->dev, "Failed to power on device\n");
		goto err_poweroff;
	}

	return 0;

err_poweroff:
	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
	return ret;
}

static int bmc150_magn_reset_intr(struct bmc150_magn_data *data)
{
	int tmp;

	/*
	 * Data Ready (DRDY) is always cleared after
	 * readout of data registers ends.
	 */
	return regmap_read(data->regmap, BMC150_MAGN_REG_X_L, &tmp);
}

static int bmc150_magn_trig_try_reen(struct iio_trigger *trig)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	if (!data->dready_trigger_on)
		return 0;

	mutex_lock(&data->mutex);
	ret = bmc150_magn_reset_intr(data);
	mutex_unlock(&data->mutex);

	return ret;
}

static int bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger *trig,
						  bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret = 0;

	mutex_lock(&data->mutex);
	if (state == data->dready_trigger_on)
		goto err_unlock;

	ret = bmc150_magn_set_power_state(data, state);
	if (ret < 0)
		goto err_unlock;

	ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_INT_DRDY,
				 BMC150_MAGN_MASK_DRDY_EN,
				 state << BMC150_MAGN_SHIFT_DRDY_EN);
	if (ret < 0)
		goto err_poweroff;

	data->dready_trigger_on = state;

	if (state) {
		ret = bmc150_magn_reset_intr(data);
		if (ret < 0)
			goto err_poweroff;
	}
	mutex_unlock(&data->mutex);

	return 0;

err_poweroff:
	bmc150_magn_set_power_state(data, false);
err_unlock:
	mutex_unlock(&data->mutex);
	return ret;
}

static const struct iio_trigger_ops bmc150_magn_trigger_ops = {
	.set_trigger_state = bmc150_magn_data_rdy_trigger_set_state,
	.try_reenable = bmc150_magn_trig_try_reen,
	.owner = THIS_MODULE,
};

static int bmc150_magn_buffer_preenable(struct iio_dev *indio_dev)
{
	struct bmc150_magn_data *data = iio_priv(indio_dev);

	return bmc150_magn_set_power_state(data, true);
}

static int bmc150_magn_buffer_postdisable(struct iio_dev *indio_dev)
{
	struct bmc150_magn_data *data = iio_priv(indio_dev);

	return bmc150_magn_set_power_state(data, false);
}

static const struct iio_buffer_setup_ops bmc150_magn_buffer_setup_ops = {
	.preenable = bmc150_magn_buffer_preenable,
	.postenable = iio_triggered_buffer_postenable,
	.predisable = iio_triggered_buffer_predisable,
	.postdisable = bmc150_magn_buffer_postdisable,
};

static int bmc150_magn_gpio_probe(struct i2c_client *client)
{
	struct device *dev;
	struct gpio_desc *gpio;
	int ret;

	if (!client)
		return -EINVAL;

	dev = &client->dev;

	/* data ready GPIO interrupt pin */
	gpio = devm_gpiod_get_index(dev, BMC150_MAGN_GPIO_INT, 0);
	if (IS_ERR(gpio)) {
		dev_err(dev, "ACPI GPIO get index failed\n");
		return PTR_ERR(gpio);
	}

	ret = gpiod_direction_input(gpio);
	if (ret)
		return ret;

	ret = gpiod_to_irq(gpio);

	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);

	return ret;
}

static const char *bmc150_magn_match_acpi_device(struct device *dev)
{
	const struct acpi_device_id *id;

	id = acpi_match_device(dev->driver->acpi_match_table, dev);
	if (!id)
		return NULL;

	return dev_name(dev);
}

static int bmc150_magn_probe(struct i2c_client *client,
			     const struct i2c_device_id *id)
{
	struct bmc150_magn_data *data;
	struct iio_dev *indio_dev;
	const char *name = NULL;
	int ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;

	if (id)
		name = id->name;
	else if (ACPI_HANDLE(&client->dev))
		name = bmc150_magn_match_acpi_device(&client->dev);
	else
		return -ENOSYS;

	mutex_init(&data->mutex);
	data->regmap = devm_regmap_init_i2c(client, &bmc150_magn_regmap_config);
	if (IS_ERR(data->regmap)) {
		dev_err(&client->dev, "Failed to allocate register map\n");
		return PTR_ERR(data->regmap);
	}

	ret = bmc150_magn_init(data);
	if (ret < 0)
		return ret;

	indio_dev->dev.parent = &client->dev;
	indio_dev->channels = bmc150_magn_channels;
	indio_dev->num_channels = ARRAY_SIZE(bmc150_magn_channels);
	indio_dev->available_scan_masks = bmc150_magn_scan_masks;
	indio_dev->name = name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &bmc150_magn_info;

	if (client->irq <= 0)
		client->irq = bmc150_magn_gpio_probe(client);

	if (client->irq > 0) {
		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
							   "%s-dev%d",
							   indio_dev->name,
							   indio_dev->id);
		if (!data->dready_trig) {
			ret = -ENOMEM;
			dev_err(&client->dev, "iio trigger alloc failed\n");
			goto err_poweroff;
		}

		data->dready_trig->dev.parent = &client->dev;
		data->dready_trig->ops = &bmc150_magn_trigger_ops;
		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
		ret = iio_trigger_register(data->dready_trig);
		if (ret) {
			dev_err(&client->dev, "iio trigger register failed\n");
			goto err_poweroff;
		}

		ret = request_threaded_irq(client->irq,
					   iio_trigger_generic_data_rdy_poll,
					   NULL,
					   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
					   BMC150_MAGN_IRQ_NAME,
					   data->dready_trig);
		if (ret < 0) {
			dev_err(&client->dev, "request irq %d failed\n",
				client->irq);
			goto err_trigger_unregister;
		}
	}

	ret = iio_triggered_buffer_setup(indio_dev,
					 iio_pollfunc_store_time,
					 bmc150_magn_trigger_handler,
					 &bmc150_magn_buffer_setup_ops);
	if (ret < 0) {
		dev_err(&client->dev,
			"iio triggered buffer setup failed\n");
		goto err_free_irq;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "unable to register iio device\n");
		goto err_buffer_cleanup;
	}

	ret = pm_runtime_set_active(&client->dev);
	if (ret)
		goto err_iio_unregister;

	pm_runtime_enable(&client->dev);
	pm_runtime_set_autosuspend_delay(&client->dev,
					 BMC150_MAGN_AUTO_SUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(&client->dev);

	dev_dbg(&indio_dev->dev, "Registered device %s\n", name);

	return 0;

err_iio_unregister:
	iio_device_unregister(indio_dev);
err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_free_irq:
	if (client->irq > 0)
		free_irq(client->irq, data->dready_trig);
err_trigger_unregister:
	if (data->dready_trig)
		iio_trigger_unregister(data->dready_trig);
err_poweroff:
	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
	return ret;
}

static int bmc150_magn_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct bmc150_magn_data *data = iio_priv(indio_dev);

	pm_runtime_disable(&client->dev);
	pm_runtime_set_suspended(&client->dev);
	pm_runtime_put_noidle(&client->dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	if (client->irq > 0)
		free_irq(data->client->irq, data->dready_trig);

	if (data->dready_trig)
		iio_trigger_unregister(data->dready_trig);

	mutex_lock(&data->mutex);
	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
	mutex_unlock(&data->mutex);

	return 0;
}

#ifdef CONFIG_PM
static int bmc150_magn_runtime_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
					 true);
	mutex_unlock(&data->mutex);
	if (ret < 0) {
		dev_err(&data->client->dev, "powering off device failed\n");
		return ret;
	}
	return 0;
}

static int bmc150_magn_runtime_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bmc150_magn_data *data = iio_priv(indio_dev);

	return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
					  true);
}
#endif

#ifdef CONFIG_PM_SLEEP
static int bmc150_magn_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
					 true);
	mutex_unlock(&data->mutex);

	return ret;
}

static int bmc150_magn_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct bmc150_magn_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
					 true);
	mutex_unlock(&data->mutex);

	return ret;
}
#endif

static const struct dev_pm_ops bmc150_magn_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(bmc150_magn_suspend, bmc150_magn_resume)
	SET_RUNTIME_PM_OPS(bmc150_magn_runtime_suspend,
			   bmc150_magn_runtime_resume, NULL)
};

static const struct acpi_device_id bmc150_magn_acpi_match[] = {
	{"BMC150B", 0},
	{"BMC156B", 0},
	{},
};
MODULE_DEVICE_TABLE(acpi, bmc150_magn_acpi_match);

static const struct i2c_device_id bmc150_magn_id[] = {
	{"bmc150_magn", 0},
	{"bmc156_magn", 0},
	{},
};
MODULE_DEVICE_TABLE(i2c, bmc150_magn_id);

static struct i2c_driver bmc150_magn_driver = {
	.driver = {
		   .name = BMC150_MAGN_DRV_NAME,
		   .acpi_match_table = ACPI_PTR(bmc150_magn_acpi_match),
		   .pm = &bmc150_magn_pm_ops,
		   },
	.probe = bmc150_magn_probe,
	.remove = bmc150_magn_remove,
	.id_table = bmc150_magn_id,
};
module_i2c_driver(bmc150_magn_driver);

MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("BMC150 magnetometer driver");