aboutsummaryrefslogtreecommitdiff
path: root/drivers/iio/proximity/sx9500.c
blob: 9ea147f1a50d10ee13412d41bac823f605bfc1b2 (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
/*
 * Copyright (c) 2014 Intel Corporation
 *
 * Driver for Semtech's SX9500 capacitive proximity/button solution.
 * Datasheet available at
 * <http://www.semtech.com/images/datasheet/sx9500.pdf>.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
#include <linux/regmap.h>
#include <linux/pm.h>
#include <linux/delay.h>

#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>

#define SX9500_DRIVER_NAME		"sx9500"
#define SX9500_IRQ_NAME			"sx9500_event"

#define SX9500_GPIO_INT			"interrupt"
#define SX9500_GPIO_RESET		"reset"

/* Register definitions. */
#define SX9500_REG_IRQ_SRC		0x00
#define SX9500_REG_STAT			0x01
#define SX9500_REG_IRQ_MSK		0x03

#define SX9500_REG_PROX_CTRL0		0x06
#define SX9500_REG_PROX_CTRL1		0x07
#define SX9500_REG_PROX_CTRL2		0x08
#define SX9500_REG_PROX_CTRL3		0x09
#define SX9500_REG_PROX_CTRL4		0x0a
#define SX9500_REG_PROX_CTRL5		0x0b
#define SX9500_REG_PROX_CTRL6		0x0c
#define SX9500_REG_PROX_CTRL7		0x0d
#define SX9500_REG_PROX_CTRL8		0x0e

#define SX9500_REG_SENSOR_SEL		0x20
#define SX9500_REG_USE_MSB		0x21
#define SX9500_REG_USE_LSB		0x22
#define SX9500_REG_AVG_MSB		0x23
#define SX9500_REG_AVG_LSB		0x24
#define SX9500_REG_DIFF_MSB		0x25
#define SX9500_REG_DIFF_LSB		0x26
#define SX9500_REG_OFFSET_MSB		0x27
#define SX9500_REG_OFFSET_LSB		0x28

#define SX9500_REG_RESET		0x7f

/* Write this to REG_RESET to do a soft reset. */
#define SX9500_SOFT_RESET		0xde

#define SX9500_SCAN_PERIOD_MASK		GENMASK(6, 4)
#define SX9500_SCAN_PERIOD_SHIFT	4

/*
 * These serve for identifying IRQ source in the IRQ_SRC register, and
 * also for masking the IRQs in the IRQ_MSK register.
 */
#define SX9500_CLOSE_IRQ		BIT(6)
#define SX9500_FAR_IRQ			BIT(5)
#define SX9500_CONVDONE_IRQ		BIT(3)

#define SX9500_PROXSTAT_SHIFT		4
#define SX9500_COMPSTAT_MASK		GENMASK(3, 0)

#define SX9500_NUM_CHANNELS		4
#define SX9500_CHAN_MASK		GENMASK(SX9500_NUM_CHANNELS - 1, 0)

struct sx9500_data {
	struct mutex mutex;
	struct i2c_client *client;
	struct iio_trigger *trig;
	struct regmap *regmap;
	struct gpio_desc *gpiod_rst;
	/*
	 * Last reading of the proximity status for each channel.  We
	 * only send an event to user space when this changes.
	 */
	bool prox_stat[SX9500_NUM_CHANNELS];
	bool event_enabled[SX9500_NUM_CHANNELS];
	bool trigger_enabled;
	u16 *buffer;
	/* Remember enabled channels and sample rate during suspend. */
	unsigned int suspend_ctrl0;
	struct completion completion;
	int data_rdy_users, close_far_users;
	int channel_users[SX9500_NUM_CHANNELS];
};

static const struct iio_event_spec sx9500_events[] = {
	{
		.type = IIO_EV_TYPE_THRESH,
		.dir = IIO_EV_DIR_EITHER,
		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
	},
};

#define SX9500_CHANNEL(idx)					\
	{							\
		.type = IIO_PROXIMITY,				\
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
		.indexed = 1,					\
		.channel = idx,					\
		.event_spec = sx9500_events,			\
		.num_event_specs = ARRAY_SIZE(sx9500_events),	\
		.scan_index = idx,				\
		.scan_type = {					\
			.sign = 'u',				\
			.realbits = 16,				\
			.storagebits = 16,			\
			.shift = 0,				\
		},						\
	}

static const struct iio_chan_spec sx9500_channels[] = {
	SX9500_CHANNEL(0),
	SX9500_CHANNEL(1),
	SX9500_CHANNEL(2),
	SX9500_CHANNEL(3),
	IIO_CHAN_SOFT_TIMESTAMP(4),
};

static const struct {
	int val;
	int val2;
} sx9500_samp_freq_table[] = {
	{33, 333333},
	{16, 666666},
	{11, 111111},
	{8, 333333},
	{6, 666666},
	{5, 0},
	{3, 333333},
	{2, 500000},
};

static const unsigned int sx9500_scan_period_table[] = {
	30, 60, 90, 120, 150, 200, 300, 400,
};

static const struct regmap_range sx9500_writable_reg_ranges[] = {
	regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
	regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
	regmap_reg_range(SX9500_REG_SENSOR_SEL, SX9500_REG_SENSOR_SEL),
	regmap_reg_range(SX9500_REG_OFFSET_MSB, SX9500_REG_OFFSET_LSB),
	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
};

static const struct regmap_access_table sx9500_writeable_regs = {
	.yes_ranges = sx9500_writable_reg_ranges,
	.n_yes_ranges = ARRAY_SIZE(sx9500_writable_reg_ranges),
};

/*
 * All allocated registers are readable, so we just list unallocated
 * ones.
 */
static const struct regmap_range sx9500_non_readable_reg_ranges[] = {
	regmap_reg_range(SX9500_REG_STAT + 1, SX9500_REG_STAT + 1),
	regmap_reg_range(SX9500_REG_IRQ_MSK + 1, SX9500_REG_PROX_CTRL0 - 1),
	regmap_reg_range(SX9500_REG_PROX_CTRL8 + 1, SX9500_REG_SENSOR_SEL - 1),
	regmap_reg_range(SX9500_REG_OFFSET_LSB + 1, SX9500_REG_RESET - 1),
};

static const struct regmap_access_table sx9500_readable_regs = {
	.no_ranges = sx9500_non_readable_reg_ranges,
	.n_no_ranges = ARRAY_SIZE(sx9500_non_readable_reg_ranges),
};

static const struct regmap_range sx9500_volatile_reg_ranges[] = {
	regmap_reg_range(SX9500_REG_IRQ_SRC, SX9500_REG_STAT),
	regmap_reg_range(SX9500_REG_USE_MSB, SX9500_REG_OFFSET_LSB),
	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
};

static const struct regmap_access_table sx9500_volatile_regs = {
	.yes_ranges = sx9500_volatile_reg_ranges,
	.n_yes_ranges = ARRAY_SIZE(sx9500_volatile_reg_ranges),
};

static const struct regmap_config sx9500_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = SX9500_REG_RESET,
	.cache_type = REGCACHE_RBTREE,

	.wr_table = &sx9500_writeable_regs,
	.rd_table = &sx9500_readable_regs,
	.volatile_table = &sx9500_volatile_regs,
};

static int sx9500_inc_users(struct sx9500_data *data, int *counter,
			    unsigned int reg, unsigned int bitmask)
{
	(*counter)++;
	if (*counter != 1)
		/* Bit is already active, nothing to do. */
		return 0;

	return regmap_update_bits(data->regmap, reg, bitmask, bitmask);
}

static int sx9500_dec_users(struct sx9500_data *data, int *counter,
			    unsigned int reg, unsigned int bitmask)
{
	(*counter)--;
	if (*counter != 0)
		/* There are more users, do not deactivate. */
		return 0;

	return regmap_update_bits(data->regmap, reg, bitmask, 0);
}

static int sx9500_inc_chan_users(struct sx9500_data *data, int chan)
{
	return sx9500_inc_users(data, &data->channel_users[chan],
				SX9500_REG_PROX_CTRL0, BIT(chan));
}

static int sx9500_dec_chan_users(struct sx9500_data *data, int chan)
{
	return sx9500_dec_users(data, &data->channel_users[chan],
				SX9500_REG_PROX_CTRL0, BIT(chan));
}

static int sx9500_inc_data_rdy_users(struct sx9500_data *data)
{
	return sx9500_inc_users(data, &data->data_rdy_users,
				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
}

static int sx9500_dec_data_rdy_users(struct sx9500_data *data)
{
	return sx9500_dec_users(data, &data->data_rdy_users,
				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
}

static int sx9500_inc_close_far_users(struct sx9500_data *data)
{
	return sx9500_inc_users(data, &data->close_far_users,
				SX9500_REG_IRQ_MSK,
				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
}

static int sx9500_dec_close_far_users(struct sx9500_data *data)
{
	return sx9500_dec_users(data, &data->close_far_users,
				SX9500_REG_IRQ_MSK,
				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
}

static int sx9500_read_prox_data(struct sx9500_data *data,
				 const struct iio_chan_spec *chan,
				 int *val)
{
	int ret;
	__be16 regval;

	ret = regmap_write(data->regmap, SX9500_REG_SENSOR_SEL, chan->channel);
	if (ret < 0)
		return ret;

	ret = regmap_bulk_read(data->regmap, SX9500_REG_USE_MSB, &regval, 2);
	if (ret < 0)
		return ret;

	*val = be16_to_cpu(regval);

	return IIO_VAL_INT;
}

/*
 * If we have no interrupt support, we have to wait for a scan period
 * after enabling a channel to get a result.
 */
static int sx9500_wait_for_sample(struct sx9500_data *data)
{
	int ret;
	unsigned int val;

	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &val);
	if (ret < 0)
		return ret;

	val = (val & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;

	msleep(sx9500_scan_period_table[val]);

	return 0;
}

static int sx9500_read_proximity(struct sx9500_data *data,
				 const struct iio_chan_spec *chan,
				 int *val)
{
	int ret;

	mutex_lock(&data->mutex);

	ret = sx9500_inc_chan_users(data, chan->channel);
	if (ret < 0)
		goto out;

	ret = sx9500_inc_data_rdy_users(data);
	if (ret < 0)
		goto out_dec_chan;

	mutex_unlock(&data->mutex);

	if (data->client->irq > 0)
		ret = wait_for_completion_interruptible(&data->completion);
	else
		ret = sx9500_wait_for_sample(data);

	mutex_lock(&data->mutex);

	if (ret < 0)
		goto out_dec_data_rdy;

	ret = sx9500_read_prox_data(data, chan, val);
	if (ret < 0)
		goto out_dec_data_rdy;

	ret = sx9500_dec_data_rdy_users(data);
	if (ret < 0)
		goto out_dec_chan;

	ret = sx9500_dec_chan_users(data, chan->channel);
	if (ret < 0)
		goto out;

	ret = IIO_VAL_INT;

	goto out;

out_dec_data_rdy:
	sx9500_dec_data_rdy_users(data);
out_dec_chan:
	sx9500_dec_chan_users(data, chan->channel);
out:
	mutex_unlock(&data->mutex);
	reinit_completion(&data->completion);

	return ret;
}

static int sx9500_read_samp_freq(struct sx9500_data *data,
				 int *val, int *val2)
{
	int ret;
	unsigned int regval;

	mutex_lock(&data->mutex);
	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &regval);
	mutex_unlock(&data->mutex);

	if (ret < 0)
		return ret;

	regval = (regval & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
	*val = sx9500_samp_freq_table[regval].val;
	*val2 = sx9500_samp_freq_table[regval].val2;

	return IIO_VAL_INT_PLUS_MICRO;
}

static int sx9500_read_raw(struct iio_dev *indio_dev,
			   const struct iio_chan_spec *chan,
			   int *val, int *val2, long mask)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;

	switch (chan->type) {
	case IIO_PROXIMITY:
		switch (mask) {
		case IIO_CHAN_INFO_RAW:
			ret = iio_device_claim_direct_mode(indio_dev);
			if (ret)
				return ret;
			ret = sx9500_read_proximity(data, chan, val);
			iio_device_release_direct_mode(indio_dev);
			return ret;
		case IIO_CHAN_INFO_SAMP_FREQ:
			return sx9500_read_samp_freq(data, val, val2);
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static int sx9500_set_samp_freq(struct sx9500_data *data,
				int val, int val2)
{
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
		if (val == sx9500_samp_freq_table[i].val &&
		    val2 == sx9500_samp_freq_table[i].val2)
			break;

	if (i == ARRAY_SIZE(sx9500_samp_freq_table))
		return -EINVAL;

	mutex_lock(&data->mutex);

	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
				 SX9500_SCAN_PERIOD_MASK,
				 i << SX9500_SCAN_PERIOD_SHIFT);

	mutex_unlock(&data->mutex);

	return ret;
}

static int sx9500_write_raw(struct iio_dev *indio_dev,
			    const struct iio_chan_spec *chan,
			    int val, int val2, long mask)
{
	struct sx9500_data *data = iio_priv(indio_dev);

	switch (chan->type) {
	case IIO_PROXIMITY:
		switch (mask) {
		case IIO_CHAN_INFO_SAMP_FREQ:
			return sx9500_set_samp_freq(data, val, val2);
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static irqreturn_t sx9500_irq_handler(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct sx9500_data *data = iio_priv(indio_dev);

	if (data->trigger_enabled)
		iio_trigger_poll(data->trig);

	/*
	 * Even if no event is enabled, we need to wake the thread to
	 * clear the interrupt state by reading SX9500_REG_IRQ_SRC.  It
	 * is not possible to do that here because regmap_read takes a
	 * mutex.
	 */
	return IRQ_WAKE_THREAD;
}

static void sx9500_push_events(struct iio_dev *indio_dev)
{
	int ret;
	unsigned int val, chan;
	struct sx9500_data *data = iio_priv(indio_dev);

	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
	if (ret < 0) {
		dev_err(&data->client->dev, "i2c transfer error in irq\n");
		return;
	}

	val >>= SX9500_PROXSTAT_SHIFT;
	for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
		int dir;
		u64 ev;
		bool new_prox = val & BIT(chan);

		if (!data->event_enabled[chan])
			continue;
		if (new_prox == data->prox_stat[chan])
			/* No change on this channel. */
			continue;

		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
					  IIO_EV_TYPE_THRESH, dir);
		iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
		data->prox_stat[chan] = new_prox;
	}
}

static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;
	unsigned int val;

	mutex_lock(&data->mutex);

	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
	if (ret < 0) {
		dev_err(&data->client->dev, "i2c transfer error in irq\n");
		goto out;
	}

	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
		sx9500_push_events(indio_dev);

	if (val & SX9500_CONVDONE_IRQ)
		complete(&data->completion);

out:
	mutex_unlock(&data->mutex);

	return IRQ_HANDLED;
}

static int sx9500_read_event_config(struct iio_dev *indio_dev,
				    const struct iio_chan_spec *chan,
				    enum iio_event_type type,
				    enum iio_event_direction dir)
{
	struct sx9500_data *data = iio_priv(indio_dev);

	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
	    dir != IIO_EV_DIR_EITHER)
		return -EINVAL;

	return data->event_enabled[chan->channel];
}

static int sx9500_write_event_config(struct iio_dev *indio_dev,
				     const struct iio_chan_spec *chan,
				     enum iio_event_type type,
				     enum iio_event_direction dir,
				     int state)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;

	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
	    dir != IIO_EV_DIR_EITHER)
		return -EINVAL;

	mutex_lock(&data->mutex);

	if (state == 1) {
		ret = sx9500_inc_chan_users(data, chan->channel);
		if (ret < 0)
			goto out_unlock;
		ret = sx9500_inc_close_far_users(data);
		if (ret < 0)
			goto out_undo_chan;
	} else {
		ret = sx9500_dec_chan_users(data, chan->channel);
		if (ret < 0)
			goto out_unlock;
		ret = sx9500_dec_close_far_users(data);
		if (ret < 0)
			goto out_undo_chan;
	}

	data->event_enabled[chan->channel] = state;
	goto out_unlock;

out_undo_chan:
	if (state == 1)
		sx9500_dec_chan_users(data, chan->channel);
	else
		sx9500_inc_chan_users(data, chan->channel);
out_unlock:
	mutex_unlock(&data->mutex);
	return ret;
}

static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
				   const unsigned long *scan_mask)
{
	struct sx9500_data *data = iio_priv(indio_dev);

	mutex_lock(&data->mutex);
	kfree(data->buffer);
	data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
	mutex_unlock(&data->mutex);

	if (data->buffer == NULL)
		return -ENOMEM;

	return 0;
}

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
	"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");

static struct attribute *sx9500_attributes[] = {
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group sx9500_attribute_group = {
	.attrs = sx9500_attributes,
};

static const struct iio_info sx9500_info = {
	.driver_module = THIS_MODULE,
	.attrs = &sx9500_attribute_group,
	.read_raw = &sx9500_read_raw,
	.write_raw = &sx9500_write_raw,
	.read_event_config = &sx9500_read_event_config,
	.write_event_config = &sx9500_write_event_config,
	.update_scan_mode = &sx9500_update_scan_mode,
};

static int sx9500_set_trigger_state(struct iio_trigger *trig,
				    bool state)
{
	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);

	if (state)
		ret = sx9500_inc_data_rdy_users(data);
	else
		ret = sx9500_dec_data_rdy_users(data);
	if (ret < 0)
		goto out;

	data->trigger_enabled = state;

out:
	mutex_unlock(&data->mutex);

	return ret;
}

static const struct iio_trigger_ops sx9500_trigger_ops = {
	.set_trigger_state = sx9500_set_trigger_state,
	.owner = THIS_MODULE,
};

static irqreturn_t sx9500_trigger_handler(int irq, void *private)
{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct sx9500_data *data = iio_priv(indio_dev);
	int val, bit, ret, i = 0;

	mutex_lock(&data->mutex);

	for_each_set_bit(bit, indio_dev->active_scan_mask,
			 indio_dev->masklength) {
		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
					    &val);
		if (ret < 0)
			goto out;

		data->buffer[i++] = val;
	}

	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
					   iio_get_time_ns(indio_dev));

out:
	mutex_unlock(&data->mutex);

	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static int sx9500_buffer_preenable(struct iio_dev *indio_dev)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret = 0, i;

	mutex_lock(&data->mutex);

	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
		if (test_bit(i, indio_dev->active_scan_mask)) {
			ret = sx9500_inc_chan_users(data, i);
			if (ret)
				break;
		}

	if (ret)
		for (i = i - 1; i >= 0; i--)
			if (test_bit(i, indio_dev->active_scan_mask))
				sx9500_dec_chan_users(data, i);

	mutex_unlock(&data->mutex);

	return ret;
}

static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret = 0, i;

	iio_triggered_buffer_predisable(indio_dev);

	mutex_lock(&data->mutex);

	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
		if (test_bit(i, indio_dev->active_scan_mask)) {
			ret = sx9500_dec_chan_users(data, i);
			if (ret)
				break;
		}

	if (ret)
		for (i = i - 1; i >= 0; i--)
			if (test_bit(i, indio_dev->active_scan_mask))
				sx9500_inc_chan_users(data, i);

	mutex_unlock(&data->mutex);

	return ret;
}

static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
	.preenable = sx9500_buffer_preenable,
	.postenable = iio_triggered_buffer_postenable,
	.predisable = sx9500_buffer_predisable,
};

struct sx9500_reg_default {
	u8 reg;
	u8 def;
};

static const struct sx9500_reg_default sx9500_default_regs[] = {
	{
		.reg = SX9500_REG_PROX_CTRL1,
		/* Shield enabled, small range. */
		.def = 0x43,
	},
	{
		.reg = SX9500_REG_PROX_CTRL2,
		/* x8 gain, 167kHz frequency, finest resolution. */
		.def = 0x77,
	},
	{
		.reg = SX9500_REG_PROX_CTRL3,
		/* Doze enabled, 2x scan period doze, no raw filter. */
		.def = 0x40,
	},
	{
		.reg = SX9500_REG_PROX_CTRL4,
		/* Average threshold. */
		.def = 0x30,
	},
	{
		.reg = SX9500_REG_PROX_CTRL5,
		/*
		 * Debouncer off, lowest average negative filter,
		 * highest average postive filter.
		 */
		.def = 0x0f,
	},
	{
		.reg = SX9500_REG_PROX_CTRL6,
		/* Proximity detection threshold: 280 */
		.def = 0x0e,
	},
	{
		.reg = SX9500_REG_PROX_CTRL7,
		/*
		 * No automatic compensation, compensate each pin
		 * independently, proximity hysteresis: 32, close
		 * debouncer off, far debouncer off.
		 */
		.def = 0x00,
	},
	{
		.reg = SX9500_REG_PROX_CTRL8,
		/* No stuck timeout, no periodic compensation. */
		.def = 0x00,
	},
	{
		.reg = SX9500_REG_PROX_CTRL0,
		/* Scan period: 30ms, all sensors disabled. */
		.def = 0x00,
	},
};

/* Activate all channels and perform an initial compensation. */
static int sx9500_init_compensation(struct iio_dev *indio_dev)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int i, ret;
	unsigned int val;

	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
				 SX9500_CHAN_MASK, SX9500_CHAN_MASK);
	if (ret < 0)
		return ret;

	for (i = 10; i >= 0; i--) {
		usleep_range(10000, 20000);
		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
		if (ret < 0)
			goto out;
		if (!(val & SX9500_COMPSTAT_MASK))
			break;
	}

	if (i < 0) {
		dev_err(&data->client->dev, "initial compensation timed out");
		ret = -ETIMEDOUT;
	}

out:
	regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
			   SX9500_CHAN_MASK, 0);
	return ret;
}

static int sx9500_init_device(struct iio_dev *indio_dev)
{
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret, i;
	unsigned int val;

	if (data->gpiod_rst) {
		gpiod_set_value_cansleep(data->gpiod_rst, 0);
		usleep_range(1000, 2000);
		gpiod_set_value_cansleep(data->gpiod_rst, 1);
		usleep_range(1000, 2000);
	}

	ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
	if (ret < 0)
		return ret;

	ret = regmap_write(data->regmap, SX9500_REG_RESET,
			   SX9500_SOFT_RESET);
	if (ret < 0)
		return ret;

	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
	if (ret < 0)
		return ret;

	for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
		ret = regmap_write(data->regmap,
				   sx9500_default_regs[i].reg,
				   sx9500_default_regs[i].def);
		if (ret < 0)
			return ret;
	}

	return sx9500_init_compensation(indio_dev);
}

static void sx9500_gpio_probe(struct i2c_client *client,
			      struct sx9500_data *data)
{
	struct device *dev;

	if (!client)
		return;

	dev = &client->dev;

	data->gpiod_rst = devm_gpiod_get_index(dev, SX9500_GPIO_RESET,
					       0, GPIOD_OUT_HIGH);
	if (IS_ERR(data->gpiod_rst)) {
		dev_warn(dev, "gpio get reset pin failed\n");
		data->gpiod_rst = NULL;
	}
}

static int sx9500_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	int ret;
	struct iio_dev *indio_dev;
	struct sx9500_data *data;

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

	data = iio_priv(indio_dev);
	data->client = client;
	mutex_init(&data->mutex);
	init_completion(&data->completion);
	data->trigger_enabled = false;

	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
	if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = SX9500_DRIVER_NAME;
	indio_dev->channels = sx9500_channels;
	indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
	indio_dev->info = &sx9500_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	i2c_set_clientdata(client, indio_dev);

	sx9500_gpio_probe(client, data);

	ret = sx9500_init_device(indio_dev);
	if (ret < 0)
		return ret;

	if (client->irq <= 0)
		dev_warn(&client->dev, "no valid irq found\n");
	else {
		ret = devm_request_threaded_irq(&client->dev, client->irq,
				sx9500_irq_handler, sx9500_irq_thread_handler,
				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
				SX9500_IRQ_NAME, indio_dev);
		if (ret < 0)
			return ret;

		data->trig = devm_iio_trigger_alloc(&client->dev,
				"%s-dev%d", indio_dev->name, indio_dev->id);
		if (!data->trig)
			return -ENOMEM;

		data->trig->dev.parent = &client->dev;
		data->trig->ops = &sx9500_trigger_ops;
		iio_trigger_set_drvdata(data->trig, indio_dev);

		ret = iio_trigger_register(data->trig);
		if (ret)
			return ret;
	}

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
					 sx9500_trigger_handler,
					 &sx9500_buffer_setup_ops);
	if (ret < 0)
		goto out_trigger_unregister;

	ret = iio_device_register(indio_dev);
	if (ret < 0)
		goto out_buffer_cleanup;

	return 0;

out_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
out_trigger_unregister:
	if (client->irq > 0)
		iio_trigger_unregister(data->trig);

	return ret;
}

static int sx9500_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct sx9500_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	if (client->irq > 0)
		iio_trigger_unregister(data->trig);
	kfree(data->buffer);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int sx9500_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0,
			  &data->suspend_ctrl0);
	if (ret < 0)
		goto out;

	/*
	 * Scan period doesn't matter because when all the sensors are
	 * deactivated the device is in sleep mode.
	 */
	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0, 0);

out:
	mutex_unlock(&data->mutex);
	return ret;
}

static int sx9500_resume(struct device *dev)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct sx9500_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->mutex);
	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0,
			   data->suspend_ctrl0);
	mutex_unlock(&data->mutex);

	return ret;
}
#endif /* CONFIG_PM_SLEEP */

static const struct dev_pm_ops sx9500_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(sx9500_suspend, sx9500_resume)
};

static const struct acpi_device_id sx9500_acpi_match[] = {
	{"SSX9500", 0},
	{ },
};
MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);

static const struct of_device_id sx9500_of_match[] = {
	{ .compatible = "semtech,sx9500", },
	{ }
};
MODULE_DEVICE_TABLE(of, sx9500_of_match);

static const struct i2c_device_id sx9500_id[] = {
	{"sx9500", 0},
	{ },
};
MODULE_DEVICE_TABLE(i2c, sx9500_id);

static struct i2c_driver sx9500_driver = {
	.driver = {
		.name	= SX9500_DRIVER_NAME,
		.acpi_match_table = ACPI_PTR(sx9500_acpi_match),
		.of_match_table = of_match_ptr(sx9500_of_match),
		.pm = &sx9500_pm_ops,
	},
	.probe		= sx9500_probe,
	.remove		= sx9500_remove,
	.id_table	= sx9500_id,
};
module_i2c_driver(sx9500_driver);

MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
MODULE_LICENSE("GPL v2");