1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  MAX732x I2C Port Expander with 8/16 I/O
4 *
5 *  Copyright (C) 2007 Marvell International Ltd.
6 *  Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
7 *  Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
8 *  Copyright (C) 2015 Linus Walleij <linus.walleij@linaro.org>
9 *
10 *  Derived from drivers/gpio/pca953x.c
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/string.h>
17#include <linux/gpio/driver.h>
18#include <linux/interrupt.h>
19#include <linux/i2c.h>
20#include <linux/platform_data/max732x.h>
21
22/*
23 * Each port of MAX732x (including MAX7319) falls into one of the
24 * following three types:
25 *
26 *   - Push Pull Output
27 *   - Input
28 *   - Open Drain I/O
29 *
30 * designated by 'O', 'I' and 'P' individually according to MAXIM's
31 * datasheets. 'I' and 'P' ports are interrupt capables, some with
32 * a dedicated interrupt mask.
33 *
34 * There are two groups of I/O ports, each group usually includes
35 * up to 8 I/O ports, and is accessed by a specific I2C address:
36 *
37 *   - Group A : by I2C address 0b'110xxxx
38 *   - Group B : by I2C address 0b'101xxxx
39 *
40 * where 'xxxx' is decided by the connections of pin AD2/AD0.  The
41 * address used also affects the initial state of output signals.
42 *
43 * Within each group of ports, there are five known combinations of
44 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
45 * the detailed organization of these ports. Only Goup A is interrupt
46 * capable.
47 *
48 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
49 * and GPIOs from GROUP_A are numbered before those from GROUP_B
50 * (if there are two groups).
51 *
52 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
53 * they are not supported by this driver.
54 */
55
56#define PORT_NONE	0x0	/* '/' No Port */
57#define PORT_OUTPUT	0x1	/* 'O' Push-Pull, Output Only */
58#define PORT_INPUT	0x2	/* 'I' Input Only */
59#define PORT_OPENDRAIN	0x3	/* 'P' Open-Drain, I/O */
60
61#define IO_4I4O		0x5AA5	/* O7 O6 I5 I4 I3 I2 O1 O0 */
62#define IO_4P4O		0x5FF5	/* O7 O6 P5 P4 P3 P2 O1 O0 */
63#define IO_8I		0xAAAA	/* I7 I6 I5 I4 I3 I2 I1 I0 */
64#define IO_8P		0xFFFF	/* P7 P6 P5 P4 P3 P2 P1 P0 */
65#define IO_8O		0x5555	/* O7 O6 O5 O4 O3 O2 O1 O0 */
66
67#define GROUP_A(x)	((x) & 0xffff)	/* I2C Addr: 0b'110xxxx */
68#define GROUP_B(x)	((x) << 16)	/* I2C Addr: 0b'101xxxx */
69
70#define INT_NONE	0x0	/* No interrupt capability */
71#define INT_NO_MASK	0x1	/* Has interrupts, no mask */
72#define INT_INDEP_MASK	0x2	/* Has interrupts, independent mask */
73#define INT_MERGED_MASK 0x3	/* Has interrupts, merged mask */
74
75#define INT_CAPS(x)	(((uint64_t)(x)) << 32)
76
77enum {
78	MAX7319,
79	MAX7320,
80	MAX7321,
81	MAX7322,
82	MAX7323,
83	MAX7324,
84	MAX7325,
85	MAX7326,
86	MAX7327,
87};
88
89static uint64_t max732x_features[] = {
90	[MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
91	[MAX7320] = GROUP_B(IO_8O),
92	[MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
93	[MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
94	[MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
95	[MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
96	[MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
97	[MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
98	[MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
99};
100
101static const struct i2c_device_id max732x_id[] = {
102	{ "max7319", MAX7319 },
103	{ "max7320", MAX7320 },
104	{ "max7321", MAX7321 },
105	{ "max7322", MAX7322 },
106	{ "max7323", MAX7323 },
107	{ "max7324", MAX7324 },
108	{ "max7325", MAX7325 },
109	{ "max7326", MAX7326 },
110	{ "max7327", MAX7327 },
111	{ },
112};
113MODULE_DEVICE_TABLE(i2c, max732x_id);
114
115static const struct of_device_id max732x_of_table[] = {
116	{ .compatible = "maxim,max7319" },
117	{ .compatible = "maxim,max7320" },
118	{ .compatible = "maxim,max7321" },
119	{ .compatible = "maxim,max7322" },
120	{ .compatible = "maxim,max7323" },
121	{ .compatible = "maxim,max7324" },
122	{ .compatible = "maxim,max7325" },
123	{ .compatible = "maxim,max7326" },
124	{ .compatible = "maxim,max7327" },
125	{ }
126};
127MODULE_DEVICE_TABLE(of, max732x_of_table);
128
129struct max732x_chip {
130	struct gpio_chip gpio_chip;
131
132	struct i2c_client *client;	/* "main" client */
133	struct i2c_client *client_dummy;
134	struct i2c_client *client_group_a;
135	struct i2c_client *client_group_b;
136
137	unsigned int	mask_group_a;
138	unsigned int	dir_input;
139	unsigned int	dir_output;
140
141	struct mutex	lock;
142	uint8_t		reg_out[2];
143
144#ifdef CONFIG_GPIO_MAX732X_IRQ
145	struct mutex		irq_lock;
146	uint8_t			irq_mask;
147	uint8_t			irq_mask_cur;
148	uint8_t			irq_trig_raise;
149	uint8_t			irq_trig_fall;
150	uint8_t			irq_features;
151#endif
152};
153
154static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
155{
156	struct i2c_client *client;
157	int ret;
158
159	client = group_a ? chip->client_group_a : chip->client_group_b;
160	ret = i2c_smbus_write_byte(client, val);
161	if (ret < 0) {
162		dev_err(&client->dev, "failed writing\n");
163		return ret;
164	}
165
166	return 0;
167}
168
169static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
170{
171	struct i2c_client *client;
172	int ret;
173
174	client = group_a ? chip->client_group_a : chip->client_group_b;
175	ret = i2c_smbus_read_byte(client);
176	if (ret < 0) {
177		dev_err(&client->dev, "failed reading\n");
178		return ret;
179	}
180
181	*val = (uint8_t)ret;
182	return 0;
183}
184
185static inline int is_group_a(struct max732x_chip *chip, unsigned off)
186{
187	return (1u << off) & chip->mask_group_a;
188}
189
190static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
191{
192	struct max732x_chip *chip = gpiochip_get_data(gc);
193	uint8_t reg_val;
194	int ret;
195
196	ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
197	if (ret < 0)
198		return ret;
199
200	return !!(reg_val & (1u << (off & 0x7)));
201}
202
203static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask,
204				  int val)
205{
206	struct max732x_chip *chip = gpiochip_get_data(gc);
207	uint8_t reg_out;
208	int ret;
209
210	mutex_lock(&chip->lock);
211
212	reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
213	reg_out = (reg_out & ~mask) | (val & mask);
214
215	ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
216	if (ret < 0)
217		goto out;
218
219	/* update the shadow register then */
220	if (off > 7)
221		chip->reg_out[1] = reg_out;
222	else
223		chip->reg_out[0] = reg_out;
224out:
225	mutex_unlock(&chip->lock);
226}
227
228static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
229{
230	unsigned base = off & ~0x7;
231	uint8_t mask = 1u << (off & 0x7);
232
233	max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
234}
235
236static void max732x_gpio_set_multiple(struct gpio_chip *gc,
237				      unsigned long *mask, unsigned long *bits)
238{
239	unsigned mask_lo = mask[0] & 0xff;
240	unsigned mask_hi = (mask[0] >> 8) & 0xff;
241
242	if (mask_lo)
243		max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
244	if (mask_hi)
245		max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
246}
247
248static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
249{
250	struct max732x_chip *chip = gpiochip_get_data(gc);
251	unsigned int mask = 1u << off;
252
253	if ((mask & chip->dir_input) == 0) {
254		dev_dbg(&chip->client->dev, "%s port %d is output only\n",
255			chip->client->name, off);
256		return -EACCES;
257	}
258
259	/*
260	 * Open-drain pins must be set to high impedance (which is
261	 * equivalent to output-high) to be turned into an input.
262	 */
263	if ((mask & chip->dir_output))
264		max732x_gpio_set_value(gc, off, 1);
265
266	return 0;
267}
268
269static int max732x_gpio_direction_output(struct gpio_chip *gc,
270		unsigned off, int val)
271{
272	struct max732x_chip *chip = gpiochip_get_data(gc);
273	unsigned int mask = 1u << off;
274
275	if ((mask & chip->dir_output) == 0) {
276		dev_dbg(&chip->client->dev, "%s port %d is input only\n",
277			chip->client->name, off);
278		return -EACCES;
279	}
280
281	max732x_gpio_set_value(gc, off, val);
282	return 0;
283}
284
285#ifdef CONFIG_GPIO_MAX732X_IRQ
286static int max732x_writew(struct max732x_chip *chip, uint16_t val)
287{
288	int ret;
289
290	val = cpu_to_le16(val);
291
292	ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
293	if (ret < 0) {
294		dev_err(&chip->client_group_a->dev, "failed writing\n");
295		return ret;
296	}
297
298	return 0;
299}
300
301static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
302{
303	int ret;
304
305	ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
306	if (ret < 0) {
307		dev_err(&chip->client_group_a->dev, "failed reading\n");
308		return ret;
309	}
310
311	*val = le16_to_cpu(*val);
312	return 0;
313}
314
315static void max732x_irq_update_mask(struct max732x_chip *chip)
316{
317	uint16_t msg;
318
319	if (chip->irq_mask == chip->irq_mask_cur)
320		return;
321
322	chip->irq_mask = chip->irq_mask_cur;
323
324	if (chip->irq_features == INT_NO_MASK)
325		return;
326
327	mutex_lock(&chip->lock);
328
329	switch (chip->irq_features) {
330	case INT_INDEP_MASK:
331		msg = (chip->irq_mask << 8) | chip->reg_out[0];
332		max732x_writew(chip, msg);
333		break;
334
335	case INT_MERGED_MASK:
336		msg = chip->irq_mask | chip->reg_out[0];
337		max732x_writeb(chip, 1, (uint8_t)msg);
338		break;
339	}
340
341	mutex_unlock(&chip->lock);
342}
343
344static void max732x_irq_mask(struct irq_data *d)
345{
346	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
347	struct max732x_chip *chip = gpiochip_get_data(gc);
348
349	chip->irq_mask_cur &= ~(1 << d->hwirq);
350	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
351}
352
353static void max732x_irq_unmask(struct irq_data *d)
354{
355	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
356	struct max732x_chip *chip = gpiochip_get_data(gc);
357
358	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
359	chip->irq_mask_cur |= 1 << d->hwirq;
360}
361
362static void max732x_irq_bus_lock(struct irq_data *d)
363{
364	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
365	struct max732x_chip *chip = gpiochip_get_data(gc);
366
367	mutex_lock(&chip->irq_lock);
368	chip->irq_mask_cur = chip->irq_mask;
369}
370
371static void max732x_irq_bus_sync_unlock(struct irq_data *d)
372{
373	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
374	struct max732x_chip *chip = gpiochip_get_data(gc);
375	uint16_t new_irqs;
376	uint16_t level;
377
378	max732x_irq_update_mask(chip);
379
380	new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
381	while (new_irqs) {
382		level = __ffs(new_irqs);
383		max732x_gpio_direction_input(&chip->gpio_chip, level);
384		new_irqs &= ~(1 << level);
385	}
386
387	mutex_unlock(&chip->irq_lock);
388}
389
390static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
391{
392	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
393	struct max732x_chip *chip = gpiochip_get_data(gc);
394	uint16_t off = d->hwirq;
395	uint16_t mask = 1 << off;
396
397	if (!(mask & chip->dir_input)) {
398		dev_dbg(&chip->client->dev, "%s port %d is output only\n",
399			chip->client->name, off);
400		return -EACCES;
401	}
402
403	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
404		dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
405			d->irq, type);
406		return -EINVAL;
407	}
408
409	if (type & IRQ_TYPE_EDGE_FALLING)
410		chip->irq_trig_fall |= mask;
411	else
412		chip->irq_trig_fall &= ~mask;
413
414	if (type & IRQ_TYPE_EDGE_RISING)
415		chip->irq_trig_raise |= mask;
416	else
417		chip->irq_trig_raise &= ~mask;
418
419	return 0;
420}
421
422static int max732x_irq_set_wake(struct irq_data *data, unsigned int on)
423{
424	struct max732x_chip *chip = irq_data_get_irq_chip_data(data);
425
426	irq_set_irq_wake(chip->client->irq, on);
427	return 0;
428}
429
430static const struct irq_chip max732x_irq_chip = {
431	.name			= "max732x",
432	.irq_mask		= max732x_irq_mask,
433	.irq_unmask		= max732x_irq_unmask,
434	.irq_bus_lock		= max732x_irq_bus_lock,
435	.irq_bus_sync_unlock	= max732x_irq_bus_sync_unlock,
436	.irq_set_type		= max732x_irq_set_type,
437	.irq_set_wake		= max732x_irq_set_wake,
438	.flags			= IRQCHIP_IMMUTABLE,
439	 GPIOCHIP_IRQ_RESOURCE_HELPERS,
440};
441
442static uint8_t max732x_irq_pending(struct max732x_chip *chip)
443{
444	uint8_t cur_stat;
445	uint8_t old_stat;
446	uint8_t trigger;
447	uint8_t pending;
448	uint16_t status;
449	int ret;
450
451	ret = max732x_readw(chip, &status);
452	if (ret)
453		return 0;
454
455	trigger = status >> 8;
456	trigger &= chip->irq_mask;
457
458	if (!trigger)
459		return 0;
460
461	cur_stat = status & 0xFF;
462	cur_stat &= chip->irq_mask;
463
464	old_stat = cur_stat ^ trigger;
465
466	pending = (old_stat & chip->irq_trig_fall) |
467		  (cur_stat & chip->irq_trig_raise);
468	pending &= trigger;
469
470	return pending;
471}
472
473static irqreturn_t max732x_irq_handler(int irq, void *devid)
474{
475	struct max732x_chip *chip = devid;
476	uint8_t pending;
477	uint8_t level;
478
479	pending = max732x_irq_pending(chip);
480
481	if (!pending)
482		return IRQ_HANDLED;
483
484	do {
485		level = __ffs(pending);
486		handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
487						   level));
488
489		pending &= ~(1 << level);
490	} while (pending);
491
492	return IRQ_HANDLED;
493}
494
495static int max732x_irq_setup(struct max732x_chip *chip,
496			     const struct i2c_device_id *id)
497{
498	struct i2c_client *client = chip->client;
499	int has_irq = max732x_features[id->driver_data] >> 32;
500	int irq_base = 0;
501	int ret;
502
503	if (client->irq && has_irq != INT_NONE) {
504		struct gpio_irq_chip *girq;
505
506		chip->irq_features = has_irq;
507		mutex_init(&chip->irq_lock);
508
509		ret = devm_request_threaded_irq(&client->dev, client->irq,
510				NULL, max732x_irq_handler, IRQF_ONESHOT |
511				IRQF_TRIGGER_FALLING | IRQF_SHARED,
512				dev_name(&client->dev), chip);
513		if (ret) {
514			dev_err(&client->dev, "failed to request irq %d\n",
515				client->irq);
516			return ret;
517		}
518
519		girq = &chip->gpio_chip.irq;
520		gpio_irq_chip_set_chip(girq, &max732x_irq_chip);
521		/* This will let us handle the parent IRQ in the driver */
522		girq->parent_handler = NULL;
523		girq->num_parents = 0;
524		girq->parents = NULL;
525		girq->default_type = IRQ_TYPE_NONE;
526		girq->handler = handle_simple_irq;
527		girq->threaded = true;
528		girq->first = irq_base; /* FIXME: get rid of this */
529	}
530
531	return 0;
532}
533
534#else /* CONFIG_GPIO_MAX732X_IRQ */
535static int max732x_irq_setup(struct max732x_chip *chip,
536			     const struct i2c_device_id *id)
537{
538	struct i2c_client *client = chip->client;
539	int has_irq = max732x_features[id->driver_data] >> 32;
540
541	if (client->irq && has_irq != INT_NONE)
542		dev_warn(&client->dev, "interrupt support not compiled in\n");
543
544	return 0;
545}
546#endif
547
548static int max732x_setup_gpio(struct max732x_chip *chip,
549					const struct i2c_device_id *id,
550					unsigned gpio_start)
551{
552	struct gpio_chip *gc = &chip->gpio_chip;
553	uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
554	int i, port = 0;
555
556	for (i = 0; i < 16; i++, id_data >>= 2) {
557		unsigned int mask = 1 << port;
558
559		switch (id_data & 0x3) {
560		case PORT_OUTPUT:
561			chip->dir_output |= mask;
562			break;
563		case PORT_INPUT:
564			chip->dir_input |= mask;
565			break;
566		case PORT_OPENDRAIN:
567			chip->dir_output |= mask;
568			chip->dir_input |= mask;
569			break;
570		default:
571			continue;
572		}
573
574		if (i < 8)
575			chip->mask_group_a |= mask;
576		port++;
577	}
578
579	if (chip->dir_input)
580		gc->direction_input = max732x_gpio_direction_input;
581	if (chip->dir_output) {
582		gc->direction_output = max732x_gpio_direction_output;
583		gc->set = max732x_gpio_set_value;
584		gc->set_multiple = max732x_gpio_set_multiple;
585	}
586	gc->get = max732x_gpio_get_value;
587	gc->can_sleep = true;
588
589	gc->base = gpio_start;
590	gc->ngpio = port;
591	gc->label = chip->client->name;
592	gc->parent = &chip->client->dev;
593	gc->owner = THIS_MODULE;
594
595	return port;
596}
597
598static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
599{
600	struct max732x_platform_data *pdata;
601
602	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
603	if (!pdata)
604		return NULL;
605
606	pdata->gpio_base = -1;
607
608	return pdata;
609}
610
611static int max732x_probe(struct i2c_client *client)
612{
613	const struct i2c_device_id *id = i2c_client_get_device_id(client);
614	struct max732x_platform_data *pdata;
615	struct device_node *node;
616	struct max732x_chip *chip;
617	struct i2c_client *c;
618	uint16_t addr_a, addr_b;
619	int ret, nr_port;
620
621	pdata = dev_get_platdata(&client->dev);
622	node = client->dev.of_node;
623
624	if (!pdata && node)
625		pdata = of_gpio_max732x(&client->dev);
626
627	if (!pdata) {
628		dev_dbg(&client->dev, "no platform data\n");
629		return -EINVAL;
630	}
631
632	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
633	if (chip == NULL)
634		return -ENOMEM;
635	chip->client = client;
636
637	nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
638	chip->gpio_chip.parent = &client->dev;
639
640	addr_a = (client->addr & 0x0f) | 0x60;
641	addr_b = (client->addr & 0x0f) | 0x50;
642
643	switch (client->addr & 0x70) {
644	case 0x60:
645		chip->client_group_a = client;
646		if (nr_port > 8) {
647			c = devm_i2c_new_dummy_device(&client->dev,
648						      client->adapter, addr_b);
649			if (IS_ERR(c)) {
650				dev_err(&client->dev,
651					"Failed to allocate I2C device\n");
652				return PTR_ERR(c);
653			}
654			chip->client_group_b = chip->client_dummy = c;
655		}
656		break;
657	case 0x50:
658		chip->client_group_b = client;
659		if (nr_port > 8) {
660			c = devm_i2c_new_dummy_device(&client->dev,
661						      client->adapter, addr_a);
662			if (IS_ERR(c)) {
663				dev_err(&client->dev,
664					"Failed to allocate I2C device\n");
665				return PTR_ERR(c);
666			}
667			chip->client_group_a = chip->client_dummy = c;
668		}
669		break;
670	default:
671		dev_err(&client->dev, "invalid I2C address specified %02x\n",
672				client->addr);
673		return -EINVAL;
674	}
675
676	if (nr_port > 8 && !chip->client_dummy) {
677		dev_err(&client->dev,
678			"Failed to allocate second group I2C device\n");
679		return -ENODEV;
680	}
681
682	mutex_init(&chip->lock);
683
684	ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
685	if (ret)
686		return ret;
687	if (nr_port > 8) {
688		ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
689		if (ret)
690			return ret;
691	}
692
693	ret = max732x_irq_setup(chip, id);
694	if (ret)
695		return ret;
696
697	ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
698	if (ret)
699		return ret;
700
701	i2c_set_clientdata(client, chip);
702	return 0;
703}
704
705static struct i2c_driver max732x_driver = {
706	.driver = {
707		.name		= "max732x",
708		.of_match_table	= max732x_of_table,
709	},
710	.probe		= max732x_probe,
711	.id_table	= max732x_id,
712};
713
714static int __init max732x_init(void)
715{
716	return i2c_add_driver(&max732x_driver);
717}
718/* register after i2c postcore initcall and before
719 * subsys initcalls that may rely on these GPIOs
720 */
721subsys_initcall(max732x_init);
722
723static void __exit max732x_exit(void)
724{
725	i2c_del_driver(&max732x_driver);
726}
727module_exit(max732x_exit);
728
729MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
730MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
731MODULE_LICENSE("GPL");
732