summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-mcp23s08.c
blob: 57adbc90fdad8f4dc821fea920f599031e602dad (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
/*
 * MCP23S08 SPI/I2C GPIO gpio expander driver
 *
 * The inputs and outputs of the mcp23s08, mcp23s17, mcp23008 and mcp23017 are
 * supported.
 * For the I2C versions of the chips (mcp23008 and mcp23017) generation of
 * interrupts is also supported.
 * The hardware of the SPI versions of the chips (mcp23s08 and mcp23s17) is
 * also capable of generating interrupts, but the linux driver does not
 * support that yet.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/spi/mcp23s08.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>

/**
 * MCP types supported by driver
 */
#define MCP_TYPE_S08	0
#define MCP_TYPE_S17	1
#define MCP_TYPE_008	2
#define MCP_TYPE_017	3

/* Registers are all 8 bits wide.
 *
 * The mcp23s17 has twice as many bits, and can be configured to work
 * with either 16 bit registers or with two adjacent 8 bit banks.
 */
#define MCP_IODIR	0x00		/* init/reset:  all ones */
#define MCP_IPOL	0x01
#define MCP_GPINTEN	0x02
#define MCP_DEFVAL	0x03
#define MCP_INTCON	0x04
#define MCP_IOCON	0x05
#	define IOCON_MIRROR	(1 << 6)
#	define IOCON_SEQOP	(1 << 5)
#	define IOCON_HAEN	(1 << 3)
#	define IOCON_ODR	(1 << 2)
#	define IOCON_INTPOL	(1 << 1)
#define MCP_GPPU	0x06
#define MCP_INTF	0x07
#define MCP_INTCAP	0x08
#define MCP_GPIO	0x09
#define MCP_OLAT	0x0a

struct mcp23s08;

struct mcp23s08_ops {
	int	(*read)(struct mcp23s08 *mcp, unsigned reg);
	int	(*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
	int	(*read_regs)(struct mcp23s08 *mcp, unsigned reg,
			     u16 *vals, unsigned n);
};

struct mcp23s08 {
	u8			addr;

	u16			cache[11];
	u16			irq_rise;
	u16			irq_fall;
	int			irq;
	bool			irq_controller;
	/* lock protects the cached values */
	struct mutex		lock;
	struct mutex		irq_lock;
	struct irq_domain	*irq_domain;

	struct gpio_chip	chip;

	const struct mcp23s08_ops	*ops;
	void			*data; /* ops specific data */
};

/* A given spi_device can represent up to eight mcp23sxx chips
 * sharing the same chipselect but using different addresses
 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
 * Driver data holds all the per-chip data.
 */
struct mcp23s08_driver_data {
	unsigned		ngpio;
	struct mcp23s08		*mcp[8];
	struct mcp23s08		chip[];
};

/* This lock class tells lockdep that GPIO irqs are in a different
 * category than their parents, so it won't report false recursion.
 */
static struct lock_class_key gpio_lock_class;

/*----------------------------------------------------------------------*/

#if IS_ENABLED(CONFIG_I2C)

static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
{
	return i2c_smbus_read_byte_data(mcp->data, reg);
}

static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
	return i2c_smbus_write_byte_data(mcp->data, reg, val);
}

static int
mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
	while (n--) {
		int ret = mcp23008_read(mcp, reg++);
		if (ret < 0)
			return ret;
		*vals++ = ret;
	}

	return 0;
}

static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
{
	return i2c_smbus_read_word_data(mcp->data, reg << 1);
}

static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
	return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
}

static int
mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
	while (n--) {
		int ret = mcp23017_read(mcp, reg++);
		if (ret < 0)
			return ret;
		*vals++ = ret;
	}

	return 0;
}

static const struct mcp23s08_ops mcp23008_ops = {
	.read		= mcp23008_read,
	.write		= mcp23008_write,
	.read_regs	= mcp23008_read_regs,
};

static const struct mcp23s08_ops mcp23017_ops = {
	.read		= mcp23017_read,
	.write		= mcp23017_write,
	.read_regs	= mcp23017_read_regs,
};

#endif /* CONFIG_I2C */

/*----------------------------------------------------------------------*/

#ifdef CONFIG_SPI_MASTER

static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
{
	u8	tx[2], rx[1];
	int	status;

	tx[0] = mcp->addr | 0x01;
	tx[1] = reg;
	status = spi_write_then_read(mcp->data, tx, sizeof(tx), rx, sizeof(rx));
	return (status < 0) ? status : rx[0];
}

static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
	u8	tx[3];

	tx[0] = mcp->addr;
	tx[1] = reg;
	tx[2] = val;
	return spi_write_then_read(mcp->data, tx, sizeof(tx), NULL, 0);
}

static int
mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
	u8	tx[2], *tmp;
	int	status;

	if ((n + reg) > sizeof(mcp->cache))
		return -EINVAL;
	tx[0] = mcp->addr | 0x01;
	tx[1] = reg;

	tmp = (u8 *)vals;
	status = spi_write_then_read(mcp->data, tx, sizeof(tx), tmp, n);
	if (status >= 0) {
		while (n--)
			vals[n] = tmp[n]; /* expand to 16bit */
	}
	return status;
}

static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
{
	u8	tx[2], rx[2];
	int	status;

	tx[0] = mcp->addr | 0x01;
	tx[1] = reg << 1;
	status = spi_write_then_read(mcp->data, tx, sizeof(tx), rx, sizeof(rx));
	return (status < 0) ? status : (rx[0] | (rx[1] << 8));
}

static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
	u8	tx[4];

	tx[0] = mcp->addr;
	tx[1] = reg << 1;
	tx[2] = val;
	tx[3] = val >> 8;
	return spi_write_then_read(mcp->data, tx, sizeof(tx), NULL, 0);
}

static int
mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
	u8	tx[2];
	int	status;

	if ((n + reg) > sizeof(mcp->cache))
		return -EINVAL;
	tx[0] = mcp->addr | 0x01;
	tx[1] = reg << 1;

	status = spi_write_then_read(mcp->data, tx, sizeof(tx),
				     (u8 *)vals, n * 2);
	if (status >= 0) {
		while (n--)
			vals[n] = __le16_to_cpu((__le16)vals[n]);
	}

	return status;
}

static const struct mcp23s08_ops mcp23s08_ops = {
	.read		= mcp23s08_read,
	.write		= mcp23s08_write,
	.read_regs	= mcp23s08_read_regs,
};

static const struct mcp23s08_ops mcp23s17_ops = {
	.read		= mcp23s17_read,
	.write		= mcp23s17_write,
	.read_regs	= mcp23s17_read_regs,
};

#endif /* CONFIG_SPI_MASTER */

/*----------------------------------------------------------------------*/

static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	int status;

	mutex_lock(&mcp->lock);
	mcp->cache[MCP_IODIR] |= (1 << offset);
	status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
	mutex_unlock(&mcp->lock);
	return status;
}

static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	int status;

	mutex_lock(&mcp->lock);

	/* REVISIT reading this clears any IRQ ... */
	status = mcp->ops->read(mcp, MCP_GPIO);
	if (status < 0)
		status = 0;
	else {
		mcp->cache[MCP_GPIO] = status;
		status = !!(status & (1 << offset));
	}
	mutex_unlock(&mcp->lock);
	return status;
}

static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
{
	unsigned olat = mcp->cache[MCP_OLAT];

	if (value)
		olat |= mask;
	else
		olat &= ~mask;
	mcp->cache[MCP_OLAT] = olat;
	return mcp->ops->write(mcp, MCP_OLAT, olat);
}

static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	unsigned mask = 1 << offset;

	mutex_lock(&mcp->lock);
	__mcp23s08_set(mcp, mask, value);
	mutex_unlock(&mcp->lock);
}

static int
mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	unsigned mask = 1 << offset;
	int status;

	mutex_lock(&mcp->lock);
	status = __mcp23s08_set(mcp, mask, value);
	if (status == 0) {
		mcp->cache[MCP_IODIR] &= ~mask;
		status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
	}
	mutex_unlock(&mcp->lock);
	return status;
}

/*----------------------------------------------------------------------*/
static irqreturn_t mcp23s08_irq(int irq, void *data)
{
	struct mcp23s08 *mcp = data;
	int intcap, intf, i;
	unsigned int child_irq;

	mutex_lock(&mcp->lock);
	intf = mcp->ops->read(mcp, MCP_INTF);
	if (intf < 0) {
		mutex_unlock(&mcp->lock);
		return IRQ_HANDLED;
	}

	mcp->cache[MCP_INTF] = intf;

	intcap = mcp->ops->read(mcp, MCP_INTCAP);
	if (intcap < 0) {
		mutex_unlock(&mcp->lock);
		return IRQ_HANDLED;
	}

	mcp->cache[MCP_INTCAP] = intcap;
	mutex_unlock(&mcp->lock);


	for (i = 0; i < mcp->chip.ngpio; i++) {
		if ((BIT(i) & mcp->cache[MCP_INTF]) &&
		    ((BIT(i) & intcap & mcp->irq_rise) ||
		     (mcp->irq_fall & ~intcap & BIT(i)))) {
			child_irq = irq_find_mapping(mcp->irq_domain, i);
			handle_nested_irq(child_irq);
		}
	}

	return IRQ_HANDLED;
}

static int mcp23s08_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);

	return irq_find_mapping(mcp->irq_domain, offset);
}

static void mcp23s08_irq_mask(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
	unsigned int pos = data->hwirq;

	mcp->cache[MCP_GPINTEN] &= ~BIT(pos);
}

static void mcp23s08_irq_unmask(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
	unsigned int pos = data->hwirq;

	mcp->cache[MCP_GPINTEN] |= BIT(pos);
}

static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
	unsigned int pos = data->hwirq;
	int status = 0;

	if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
		mcp->cache[MCP_INTCON] &= ~BIT(pos);
		mcp->irq_rise |= BIT(pos);
		mcp->irq_fall |= BIT(pos);
	} else if (type & IRQ_TYPE_EDGE_RISING) {
		mcp->cache[MCP_INTCON] &= ~BIT(pos);
		mcp->irq_rise |= BIT(pos);
		mcp->irq_fall &= ~BIT(pos);
	} else if (type & IRQ_TYPE_EDGE_FALLING) {
		mcp->cache[MCP_INTCON] &= ~BIT(pos);
		mcp->irq_rise &= ~BIT(pos);
		mcp->irq_fall |= BIT(pos);
	} else
		return -EINVAL;

	return status;
}

static void mcp23s08_irq_bus_lock(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);

	mutex_lock(&mcp->irq_lock);
}

static void mcp23s08_irq_bus_unlock(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);

	mutex_lock(&mcp->lock);
	mcp->ops->write(mcp, MCP_GPINTEN, mcp->cache[MCP_GPINTEN]);
	mcp->ops->write(mcp, MCP_DEFVAL, mcp->cache[MCP_DEFVAL]);
	mcp->ops->write(mcp, MCP_INTCON, mcp->cache[MCP_INTCON]);
	mutex_unlock(&mcp->lock);
	mutex_unlock(&mcp->irq_lock);
}

static int mcp23s08_irq_reqres(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);

	if (gpio_lock_as_irq(&mcp->chip, data->hwirq)) {
		dev_err(mcp->chip.dev,
			"unable to lock HW IRQ %lu for IRQ usage\n",
			data->hwirq);
		return -EINVAL;
	}

	return 0;
}

static void mcp23s08_irq_relres(struct irq_data *data)
{
	struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);

	gpio_unlock_as_irq(&mcp->chip, data->hwirq);
}

static struct irq_chip mcp23s08_irq_chip = {
	.name = "gpio-mcp23xxx",
	.irq_mask = mcp23s08_irq_mask,
	.irq_unmask = mcp23s08_irq_unmask,
	.irq_set_type = mcp23s08_irq_set_type,
	.irq_bus_lock = mcp23s08_irq_bus_lock,
	.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock,
	.irq_request_resources = mcp23s08_irq_reqres,
	.irq_release_resources = mcp23s08_irq_relres,
};

static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
{
	struct gpio_chip *chip = &mcp->chip;
	int err, irq, j;

	mutex_init(&mcp->irq_lock);

	mcp->irq_domain = irq_domain_add_linear(chip->of_node, chip->ngpio,
						&irq_domain_simple_ops, mcp);
	if (!mcp->irq_domain)
		return -ENODEV;

	err = devm_request_threaded_irq(chip->dev, mcp->irq, NULL, mcp23s08_irq,
					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
					dev_name(chip->dev), mcp);
	if (err != 0) {
		dev_err(chip->dev, "unable to request IRQ#%d: %d\n",
			mcp->irq, err);
		return err;
	}

	chip->to_irq = mcp23s08_gpio_to_irq;

	for (j = 0; j < mcp->chip.ngpio; j++) {
		irq = irq_create_mapping(mcp->irq_domain, j);
		irq_set_lockdep_class(irq, &gpio_lock_class);
		irq_set_chip_data(irq, mcp);
		irq_set_chip(irq, &mcp23s08_irq_chip);
		irq_set_nested_thread(irq, true);
#ifdef CONFIG_ARM
		set_irq_flags(irq, IRQF_VALID);
#else
		irq_set_noprobe(irq);
#endif
	}
	return 0;
}

static void mcp23s08_irq_teardown(struct mcp23s08 *mcp)
{
	unsigned int irq, i;

	free_irq(mcp->irq, mcp);

	for (i = 0; i < mcp->chip.ngpio; i++) {
		irq = irq_find_mapping(mcp->irq_domain, i);
		if (irq > 0)
			irq_dispose_mapping(irq);
	}

	irq_domain_remove(mcp->irq_domain);
}

/*----------------------------------------------------------------------*/

#ifdef CONFIG_DEBUG_FS

#include <linux/seq_file.h>

/*
 * This shows more info than the generic gpio dump code:
 * pullups, deglitching, open drain drive.
 */
static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	struct mcp23s08	*mcp;
	char		bank;
	int		t;
	unsigned	mask;

	mcp = container_of(chip, struct mcp23s08, chip);

	/* NOTE: we only handle one bank for now ... */
	bank = '0' + ((mcp->addr >> 1) & 0x7);

	mutex_lock(&mcp->lock);
	t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
	if (t < 0) {
		seq_printf(s, " I/O ERROR %d\n", t);
		goto done;
	}

	for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
		const char	*label;

		label = gpiochip_is_requested(chip, t);
		if (!label)
			continue;

		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
			chip->base + t, bank, t, label,
			(mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
			(mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
			(mcp->cache[MCP_GPPU] & mask) ? "up" : "  ");
		/* NOTE:  ignoring the irq-related registers */
		seq_puts(s, "\n");
	}
done:
	mutex_unlock(&mcp->lock);
}

#else
#define mcp23s08_dbg_show	NULL
#endif

/*----------------------------------------------------------------------*/

static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
			      void *data, unsigned addr, unsigned type,
			      unsigned base, unsigned pullups)
{
	int status;
	bool mirror = false;

	mutex_init(&mcp->lock);

	mcp->data = data;
	mcp->addr = addr;

	mcp->chip.direction_input = mcp23s08_direction_input;
	mcp->chip.get = mcp23s08_get;
	mcp->chip.direction_output = mcp23s08_direction_output;
	mcp->chip.set = mcp23s08_set;
	mcp->chip.dbg_show = mcp23s08_dbg_show;
#ifdef CONFIG_OF
	mcp->chip.of_gpio_n_cells = 2;
	mcp->chip.of_node = dev->of_node;
#endif

	switch (type) {
#ifdef CONFIG_SPI_MASTER
	case MCP_TYPE_S08:
		mcp->ops = &mcp23s08_ops;
		mcp->chip.ngpio = 8;
		mcp->chip.label = "mcp23s08";
		break;

	case MCP_TYPE_S17:
		mcp->ops = &mcp23s17_ops;
		mcp->chip.ngpio = 16;
		mcp->chip.label = "mcp23s17";
		break;
#endif /* CONFIG_SPI_MASTER */

#if IS_ENABLED(CONFIG_I2C)
	case MCP_TYPE_008:
		mcp->ops = &mcp23008_ops;
		mcp->chip.ngpio = 8;
		mcp->chip.label = "mcp23008";
		break;

	case MCP_TYPE_017:
		mcp->ops = &mcp23017_ops;
		mcp->chip.ngpio = 16;
		mcp->chip.label = "mcp23017";
		break;
#endif /* CONFIG_I2C */

	default:
		dev_err(dev, "invalid device type (%d)\n", type);
		return -EINVAL;
	}

	mcp->chip.base = base;
	mcp->chip.can_sleep = true;
	mcp->chip.dev = dev;
	mcp->chip.owner = THIS_MODULE;

	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
	 */

	status = mcp->ops->read(mcp, MCP_IOCON);
	if (status < 0)
		goto fail;

	mcp->irq_controller = of_property_read_bool(mcp->chip.of_node,
						"interrupt-controller");
	if (mcp->irq && mcp->irq_controller && (type == MCP_TYPE_017))
		mirror = of_property_read_bool(mcp->chip.of_node,
						"microchip,irq-mirror");

	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror) {
		/* mcp23s17 has IOCON twice, make sure they are in sync */
		status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
		status |= IOCON_HAEN | (IOCON_HAEN << 8);
		status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));
		if (mirror)
			status |= IOCON_MIRROR | (IOCON_MIRROR << 8);

		status = mcp->ops->write(mcp, MCP_IOCON, status);
		if (status < 0)
			goto fail;
	}

	/* configure ~100K pullups */
	status = mcp->ops->write(mcp, MCP_GPPU, pullups);
	if (status < 0)
		goto fail;

	status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
	if (status < 0)
		goto fail;

	/* disable inverter on input */
	if (mcp->cache[MCP_IPOL] != 0) {
		mcp->cache[MCP_IPOL] = 0;
		status = mcp->ops->write(mcp, MCP_IPOL, 0);
		if (status < 0)
			goto fail;
	}

	/* disable irqs */
	if (mcp->cache[MCP_GPINTEN] != 0) {
		mcp->cache[MCP_GPINTEN] = 0;
		status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
		if (status < 0)
			goto fail;
	}

	status = gpiochip_add(&mcp->chip);
	if (status < 0)
		goto fail;

	if (mcp->irq && mcp->irq_controller) {
		status = mcp23s08_irq_setup(mcp);
		if (status) {
			mcp23s08_irq_teardown(mcp);
			goto fail;
		}
	}
fail:
	if (status < 0)
		dev_dbg(dev, "can't setup chip %d, --> %d\n",
			addr, status);
	return status;
}

/*----------------------------------------------------------------------*/

#ifdef CONFIG_OF
#ifdef CONFIG_SPI_MASTER
static const struct of_device_id mcp23s08_spi_of_match[] = {
	{
		.compatible = "microchip,mcp23s08",
		.data = (void *) MCP_TYPE_S08,
	},
	{
		.compatible = "microchip,mcp23s17",
		.data = (void *) MCP_TYPE_S17,
	},
/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
	{
		.compatible = "mcp,mcp23s08",
		.data = (void *) MCP_TYPE_S08,
	},
	{
		.compatible = "mcp,mcp23s17",
		.data = (void *) MCP_TYPE_S17,
	},
	{ },
};
MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
#endif

#if IS_ENABLED(CONFIG_I2C)
static const struct of_device_id mcp23s08_i2c_of_match[] = {
	{
		.compatible = "microchip,mcp23008",
		.data = (void *) MCP_TYPE_008,
	},
	{
		.compatible = "microchip,mcp23017",
		.data = (void *) MCP_TYPE_017,
	},
/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
	{
		.compatible = "mcp,mcp23008",
		.data = (void *) MCP_TYPE_008,
	},
	{
		.compatible = "mcp,mcp23017",
		.data = (void *) MCP_TYPE_017,
	},
	{ },
};
MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
#endif
#endif /* CONFIG_OF */


#if IS_ENABLED(CONFIG_I2C)

static int mcp230xx_probe(struct i2c_client *client,
				    const struct i2c_device_id *id)
{
	struct mcp23s08_platform_data *pdata;
	struct mcp23s08 *mcp;
	int status, base, pullups;
	const struct of_device_id *match;

	match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match),
					&client->dev);
	pdata = dev_get_platdata(&client->dev);
	if (match || !pdata) {
		base = -1;
		pullups = 0;
		client->irq = irq_of_parse_and_map(client->dev.of_node, 0);
	} else {
		if (!gpio_is_valid(pdata->base)) {
			dev_dbg(&client->dev, "invalid platform data\n");
			return -EINVAL;
		}
		base = pdata->base;
		pullups = pdata->chip[0].pullups;
	}

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

	mcp->irq = client->irq;
	status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
				    id->driver_data, base, pullups);
	if (status)
		goto fail;

	i2c_set_clientdata(client, mcp);

	return 0;

fail:
	kfree(mcp);

	return status;
}

static int mcp230xx_remove(struct i2c_client *client)
{
	struct mcp23s08 *mcp = i2c_get_clientdata(client);
	int status;

	if (client->irq && mcp->irq_controller)
		mcp23s08_irq_teardown(mcp);

	status = gpiochip_remove(&mcp->chip);
	if (status == 0)
		kfree(mcp);

	return status;
}

static const struct i2c_device_id mcp230xx_id[] = {
	{ "mcp23008", MCP_TYPE_008 },
	{ "mcp23017", MCP_TYPE_017 },
	{ },
};
MODULE_DEVICE_TABLE(i2c, mcp230xx_id);

static struct i2c_driver mcp230xx_driver = {
	.driver = {
		.name	= "mcp230xx",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
	},
	.probe		= mcp230xx_probe,
	.remove		= mcp230xx_remove,
	.id_table	= mcp230xx_id,
};

static int __init mcp23s08_i2c_init(void)
{
	return i2c_add_driver(&mcp230xx_driver);
}

static void mcp23s08_i2c_exit(void)
{
	i2c_del_driver(&mcp230xx_driver);
}

#else

static int __init mcp23s08_i2c_init(void) { return 0; }
static void mcp23s08_i2c_exit(void) { }

#endif /* CONFIG_I2C */

/*----------------------------------------------------------------------*/

#ifdef CONFIG_SPI_MASTER

static int mcp23s08_probe(struct spi_device *spi)
{
	struct mcp23s08_platform_data	*pdata;
	unsigned			addr;
	int				chips = 0;
	struct mcp23s08_driver_data	*data;
	int				status, type;
	unsigned			base = -1,
					ngpio = 0,
					pullups[ARRAY_SIZE(pdata->chip)];
	const struct			of_device_id *match;
	u32				spi_present_mask = 0;

	match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
	if (match) {
		type = (int)(uintptr_t)match->data;
		status = of_property_read_u32(spi->dev.of_node,
			    "microchip,spi-present-mask", &spi_present_mask);
		if (status) {
			status = of_property_read_u32(spi->dev.of_node,
				    "mcp,spi-present-mask", &spi_present_mask);
			if (status) {
				dev_err(&spi->dev,
					"DT has no spi-present-mask\n");
				return -ENODEV;
			}
		}
		if ((spi_present_mask <= 0) || (spi_present_mask >= 256)) {
			dev_err(&spi->dev, "invalid spi-present-mask\n");
			return -ENODEV;
		}

		for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
			pullups[addr] = 0;
			if (spi_present_mask & (1 << addr))
				chips++;
		}
	} else {
		type = spi_get_device_id(spi)->driver_data;
		pdata = dev_get_platdata(&spi->dev);
		if (!pdata || !gpio_is_valid(pdata->base)) {
			dev_dbg(&spi->dev,
					"invalid or missing platform data\n");
			return -EINVAL;
		}

		for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
			if (!pdata->chip[addr].is_present)
				continue;
			chips++;
			if ((type == MCP_TYPE_S08) && (addr > 3)) {
				dev_err(&spi->dev,
					"mcp23s08 only supports address 0..3\n");
				return -EINVAL;
			}
			spi_present_mask |= 1 << addr;
			pullups[addr] = pdata->chip[addr].pullups;
		}

		base = pdata->base;
	}

	if (!chips)
		return -ENODEV;

	data = kzalloc(sizeof(*data) + chips * sizeof(struct mcp23s08),
			GFP_KERNEL);
	if (!data)
		return -ENOMEM;
	spi_set_drvdata(spi, data);

	for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
		if (!(spi_present_mask & (1 << addr)))
			continue;
		chips--;
		data->mcp[addr] = &data->chip[chips];
		status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
					    0x40 | (addr << 1), type, base,
					    pullups[addr]);
		if (status < 0)
			goto fail;

		if (base != -1)
			base += (type == MCP_TYPE_S17) ? 16 : 8;
		ngpio += (type == MCP_TYPE_S17) ? 16 : 8;
	}
	data->ngpio = ngpio;

	/* NOTE:  these chips have a relatively sane IRQ framework, with
	 * per-signal masking and level/edge triggering.  It's not yet
	 * handled here...
	 */

	return 0;

fail:
	for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
		int tmp;

		if (!data->mcp[addr])
			continue;
		tmp = gpiochip_remove(&data->mcp[addr]->chip);
		if (tmp < 0)
			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
	}
	kfree(data);
	return status;
}

static int mcp23s08_remove(struct spi_device *spi)
{
	struct mcp23s08_driver_data	*data = spi_get_drvdata(spi);
	unsigned			addr;
	int				status = 0;

	for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
		int tmp;

		if (!data->mcp[addr])
			continue;

		tmp = gpiochip_remove(&data->mcp[addr]->chip);
		if (tmp < 0) {
			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
			status = tmp;
		}
	}
	if (status == 0)
		kfree(data);
	return status;
}

static const struct spi_device_id mcp23s08_ids[] = {
	{ "mcp23s08", MCP_TYPE_S08 },
	{ "mcp23s17", MCP_TYPE_S17 },
	{ },
};
MODULE_DEVICE_TABLE(spi, mcp23s08_ids);

static struct spi_driver mcp23s08_driver = {
	.probe		= mcp23s08_probe,
	.remove		= mcp23s08_remove,
	.id_table	= mcp23s08_ids,
	.driver = {
		.name	= "mcp23s08",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
	},
};

static int __init mcp23s08_spi_init(void)
{
	return spi_register_driver(&mcp23s08_driver);
}

static void mcp23s08_spi_exit(void)
{
	spi_unregister_driver(&mcp23s08_driver);
}

#else

static int __init mcp23s08_spi_init(void) { return 0; }
static void mcp23s08_spi_exit(void) { }

#endif /* CONFIG_SPI_MASTER */

/*----------------------------------------------------------------------*/

static int __init mcp23s08_init(void)
{
	int ret;

	ret = mcp23s08_spi_init();
	if (ret)
		goto spi_fail;

	ret = mcp23s08_i2c_init();
	if (ret)
		goto i2c_fail;

	return 0;

 i2c_fail:
	mcp23s08_spi_exit();
 spi_fail:
	return ret;
}
/* register after spi/i2c postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(mcp23s08_init);

static void __exit mcp23s08_exit(void)
{
	mcp23s08_spi_exit();
	mcp23s08_i2c_exit();
}
module_exit(mcp23s08_exit);

MODULE_LICENSE("GPL");