gpio-max732x.c

  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 int max732x_gpio_set_value(struct gpio_chip *gc, unsigned int off,
229				  int val)
230{
231	unsigned base = off & ~0x7;
232	uint8_t mask = 1u << (off & 0x7);
233
234	max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7));
235
236	return 0;
237}
238
239static int max732x_gpio_set_multiple(struct gpio_chip *gc,
240				     unsigned long *mask, unsigned long *bits)
241{
242	unsigned mask_lo = mask[0] & 0xff;
243	unsigned mask_hi = (mask[0] >> 8) & 0xff;
244
245	if (mask_lo)
246		max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff);
247	if (mask_hi)
248		max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff);
249
250	return 0;
251}
252
253static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
254{
255	struct max732x_chip *chip = gpiochip_get_data(gc);
256	unsigned int mask = 1u << off;
257
258	if ((mask & chip->dir_input) == 0) {
259		dev_dbg(&chip->client->dev, "%s port %d is output only\n",
260			chip->client->name, off);
261		return -EACCES;
262	}
263
264	/*
265	 * Open-drain pins must be set to high impedance (which is
266	 * equivalent to output-high) to be turned into an input.
267	 */
268	if ((mask & chip->dir_output))
269		max732x_gpio_set_value(gc, off, 1);
270
271	return 0;
272}
273
274static int max732x_gpio_direction_output(struct gpio_chip *gc,
275		unsigned off, int val)
276{
277	struct max732x_chip *chip = gpiochip_get_data(gc);
278	unsigned int mask = 1u << off;
279
280	if ((mask & chip->dir_output) == 0) {
281		dev_dbg(&chip->client->dev, "%s port %d is input only\n",
282			chip->client->name, off);
283		return -EACCES;
284	}
285
286	max732x_gpio_set_value(gc, off, val);
287	return 0;
288}
289
290#ifdef CONFIG_GPIO_MAX732X_IRQ
291static int max732x_writew(struct max732x_chip *chip, uint16_t val)
292{
293	int ret;
294
295	val = cpu_to_le16(val);
296
297	ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
298	if (ret < 0) {
299		dev_err(&chip->client_group_a->dev, "failed writing\n");
300		return ret;
301	}
302
303	return 0;
304}
305
306static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
307{
308	int ret;
309
310	ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
311	if (ret < 0) {
312		dev_err(&chip->client_group_a->dev, "failed reading\n");
313		return ret;
314	}
315
316	*val = le16_to_cpu(*val);
317	return 0;
318}
319
320static void max732x_irq_update_mask(struct max732x_chip *chip)
321{
322	uint16_t msg;
323
324	if (chip->irq_mask == chip->irq_mask_cur)
325		return;
326
327	chip->irq_mask = chip->irq_mask_cur;
328
329	if (chip->irq_features == INT_NO_MASK)
330		return;
331
332	mutex_lock(&chip->lock);
333
334	switch (chip->irq_features) {
335	case INT_INDEP_MASK:
336		msg = (chip->irq_mask << 8) | chip->reg_out[0];
337		max732x_writew(chip, msg);
338		break;
339
340	case INT_MERGED_MASK:
341		msg = chip->irq_mask | chip->reg_out[0];
342		max732x_writeb(chip, 1, (uint8_t)msg);
343		break;
344	}
345
346	mutex_unlock(&chip->lock);
347}
348
349static void max732x_irq_mask(struct irq_data *d)
350{
351	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
352	struct max732x_chip *chip = gpiochip_get_data(gc);
353
354	chip->irq_mask_cur &= ~(1 << d->hwirq);
355	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
356}
357
358static void max732x_irq_unmask(struct irq_data *d)
359{
360	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
361	struct max732x_chip *chip = gpiochip_get_data(gc);
362
363	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
364	chip->irq_mask_cur |= 1 << d->hwirq;
365}
366
367static void max732x_irq_bus_lock(struct irq_data *d)
368{
369	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
370	struct max732x_chip *chip = gpiochip_get_data(gc);
371
372	mutex_lock(&chip->irq_lock);
373	chip->irq_mask_cur = chip->irq_mask;
374}
375
376static void max732x_irq_bus_sync_unlock(struct irq_data *d)
377{
378	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
379	struct max732x_chip *chip = gpiochip_get_data(gc);
380	uint16_t new_irqs;
381	uint16_t level;
382
383	max732x_irq_update_mask(chip);
384
385	new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
386	while (new_irqs) {
387		level = __ffs(new_irqs);
388		max732x_gpio_direction_input(&chip->gpio_chip, level);
389		new_irqs &= ~(1 << level);
390	}
391
392	mutex_unlock(&chip->irq_lock);
393}
394
395static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
396{
397	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
398	struct max732x_chip *chip = gpiochip_get_data(gc);
399	uint16_t off = d->hwirq;
400	uint16_t mask = 1 << off;
401
402	if (!(mask & chip->dir_input)) {
403		dev_dbg(&chip->client->dev, "%s port %d is output only\n",
404			chip->client->name, off);
405		return -EACCES;
406	}
407
408	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
409		dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
410			d->irq, type);
411		return -EINVAL;
412	}
413
414	if (type & IRQ_TYPE_EDGE_FALLING)
415		chip->irq_trig_fall |= mask;
416	else
417		chip->irq_trig_fall &= ~mask;
418
419	if (type & IRQ_TYPE_EDGE_RISING)
420		chip->irq_trig_raise |= mask;
421	else
422		chip->irq_trig_raise &= ~mask;
423
424	return 0;
425}
426
427static int max732x_irq_set_wake(struct irq_data *data, unsigned int on)
428{
429	struct max732x_chip *chip = irq_data_get_irq_chip_data(data);
430
431	irq_set_irq_wake(chip->client->irq, on);
432	return 0;
433}
434
435static const struct irq_chip max732x_irq_chip = {
436	.name			= "max732x",
437	.irq_mask		= max732x_irq_mask,
438	.irq_unmask		= max732x_irq_unmask,
439	.irq_bus_lock		= max732x_irq_bus_lock,
440	.irq_bus_sync_unlock	= max732x_irq_bus_sync_unlock,
441	.irq_set_type		= max732x_irq_set_type,
442	.irq_set_wake		= max732x_irq_set_wake,
443	.flags			= IRQCHIP_IMMUTABLE,
444	 GPIOCHIP_IRQ_RESOURCE_HELPERS,
445};
446
447static uint8_t max732x_irq_pending(struct max732x_chip *chip)
448{
449	uint8_t cur_stat;
450	uint8_t old_stat;
451	uint8_t trigger;
452	uint8_t pending;
453	uint16_t status;
454	int ret;
455
456	ret = max732x_readw(chip, &status);
457	if (ret)
458		return 0;
459
460	trigger = status >> 8;
461	trigger &= chip->irq_mask;
462
463	if (!trigger)
464		return 0;
465
466	cur_stat = status & 0xFF;
467	cur_stat &= chip->irq_mask;
468
469	old_stat = cur_stat ^ trigger;
470
471	pending = (old_stat & chip->irq_trig_fall) |
472		  (cur_stat & chip->irq_trig_raise);
473	pending &= trigger;
474
475	return pending;
476}
477
478static irqreturn_t max732x_irq_handler(int irq, void *devid)
479{
480	struct max732x_chip *chip = devid;
481	uint8_t pending;
482	uint8_t level;
483
484	pending = max732x_irq_pending(chip);
485
486	if (!pending)
487		return IRQ_HANDLED;
488
489	do {
490		level = __ffs(pending);
491		handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
492						   level));
493
494		pending &= ~(1 << level);
495	} while (pending);
496
497	return IRQ_HANDLED;
498}
499
500static int max732x_irq_setup(struct max732x_chip *chip,
501			     const struct i2c_device_id *id)
502{
503	struct i2c_client *client = chip->client;
504	int has_irq = max732x_features[id->driver_data] >> 32;
505	int irq_base = 0;
506	int ret;
507
508	if (client->irq && has_irq != INT_NONE) {
509		struct gpio_irq_chip *girq;
510
511		chip->irq_features = has_irq;
512		mutex_init(&chip->irq_lock);
513
514		ret = devm_request_threaded_irq(&client->dev, client->irq,
515				NULL, max732x_irq_handler, IRQF_ONESHOT |
516				IRQF_TRIGGER_FALLING | IRQF_SHARED,
517				dev_name(&client->dev), chip);
518		if (ret) {
519			dev_err(&client->dev, "failed to request irq %d\n",
520				client->irq);
521			return ret;
522		}
523
524		girq = &chip->gpio_chip.irq;
525		gpio_irq_chip_set_chip(girq, &max732x_irq_chip);
526		/* This will let us handle the parent IRQ in the driver */
527		girq->parent_handler = NULL;
528		girq->num_parents = 0;
529		girq->parents = NULL;
530		girq->default_type = IRQ_TYPE_NONE;
531		girq->handler = handle_simple_irq;
532		girq->threaded = true;
533		girq->first = irq_base; /* FIXME: get rid of this */
534	}
535
536	return 0;
537}
538
539#else /* CONFIG_GPIO_MAX732X_IRQ */
540static int max732x_irq_setup(struct max732x_chip *chip,
541			     const struct i2c_device_id *id)
542{
543	struct i2c_client *client = chip->client;
544	int has_irq = max732x_features[id->driver_data] >> 32;
545
546	if (client->irq && has_irq != INT_NONE)
547		dev_warn(&client->dev, "interrupt support not compiled in\n");
548
549	return 0;
550}
551#endif
552
553static int max732x_setup_gpio(struct max732x_chip *chip,
554					const struct i2c_device_id *id,
555					unsigned gpio_start)
556{
557	struct gpio_chip *gc = &chip->gpio_chip;
558	uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
559	int i, port = 0;
560
561	for (i = 0; i < 16; i++, id_data >>= 2) {
562		unsigned int mask = 1 << port;
563
564		switch (id_data & 0x3) {
565		case PORT_OUTPUT:
566			chip->dir_output |= mask;
567			break;
568		case PORT_INPUT:
569			chip->dir_input |= mask;
570			break;
571		case PORT_OPENDRAIN:
572			chip->dir_output |= mask;
573			chip->dir_input |= mask;
574			break;
575		default:
576			continue;
577		}
578
579		if (i < 8)
580			chip->mask_group_a |= mask;
581		port++;
582	}
583
584	if (chip->dir_input)
585		gc->direction_input = max732x_gpio_direction_input;
586	if (chip->dir_output) {
587		gc->direction_output = max732x_gpio_direction_output;
588		gc->set = max732x_gpio_set_value;
589		gc->set_multiple = max732x_gpio_set_multiple;
590	}
591	gc->get = max732x_gpio_get_value;
592	gc->can_sleep = true;
593
594	gc->base = gpio_start;
595	gc->ngpio = port;
596	gc->label = chip->client->name;
597	gc->parent = &chip->client->dev;
598	gc->owner = THIS_MODULE;
599
600	return port;
601}
602
603static struct max732x_platform_data *of_gpio_max732x(struct device *dev)
604{
605	struct max732x_platform_data *pdata;
606
607	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
608	if (!pdata)
609		return NULL;
610
611	pdata->gpio_base = -1;
612
613	return pdata;
614}
615
616static int max732x_probe(struct i2c_client *client)
617{
618	const struct i2c_device_id *id = i2c_client_get_device_id(client);
619	struct max732x_platform_data *pdata;
620	struct device_node *node;
621	struct max732x_chip *chip;
622	struct i2c_client *c;
623	uint16_t addr_a, addr_b;
624	int ret, nr_port;
625
626	pdata = dev_get_platdata(&client->dev);
627	node = client->dev.of_node;
628
629	if (!pdata && node)
630		pdata = of_gpio_max732x(&client->dev);
631
632	if (!pdata) {
633		dev_dbg(&client->dev, "no platform data\n");
634		return -EINVAL;
635	}
636
637	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
638	if (chip == NULL)
639		return -ENOMEM;
640	chip->client = client;
641
642	nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
643	chip->gpio_chip.parent = &client->dev;
644
645	addr_a = (client->addr & 0x0f) | 0x60;
646	addr_b = (client->addr & 0x0f) | 0x50;
647
648	switch (client->addr & 0x70) {
649	case 0x60:
650		chip->client_group_a = client;
651		if (nr_port > 8) {
652			c = devm_i2c_new_dummy_device(&client->dev,
653						      client->adapter, addr_b);
654			if (IS_ERR(c)) {
655				dev_err(&client->dev,
656					"Failed to allocate I2C device\n");
657				return PTR_ERR(c);
658			}
659			chip->client_group_b = chip->client_dummy = c;
660		}
661		break;
662	case 0x50:
663		chip->client_group_b = client;
664		if (nr_port > 8) {
665			c = devm_i2c_new_dummy_device(&client->dev,
666						      client->adapter, addr_a);
667			if (IS_ERR(c)) {
668				dev_err(&client->dev,
669					"Failed to allocate I2C device\n");
670				return PTR_ERR(c);
671			}
672			chip->client_group_a = chip->client_dummy = c;
673		}
674		break;
675	default:
676		dev_err(&client->dev, "invalid I2C address specified %02x\n",
677				client->addr);
678		return -EINVAL;
679	}
680
681	if (nr_port > 8 && !chip->client_dummy) {
682		dev_err(&client->dev,
683			"Failed to allocate second group I2C device\n");
684		return -ENODEV;
685	}
686
687	mutex_init(&chip->lock);
688
689	ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
690	if (ret)
691		return ret;
692	if (nr_port > 8) {
693		ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
694		if (ret)
695			return ret;
696	}
697
698	ret = max732x_irq_setup(chip, id);
699	if (ret)
700		return ret;
701
702	ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
703	if (ret)
704		return ret;
705
706	i2c_set_clientdata(client, chip);
707	return 0;
708}
709
710static struct i2c_driver max732x_driver = {
711	.driver = {
712		.name		= "max732x",
713		.of_match_table	= max732x_of_table,
714	},
715	.probe		= max732x_probe,
716	.id_table	= max732x_id,
717};
718
719static int __init max732x_init(void)
720{
721	return i2c_add_driver(&max732x_driver);
722}
723/* register after i2c postcore initcall and before
724 * subsys initcalls that may rely on these GPIOs
725 */
726subsys_initcall(max732x_init);
727
728static void __exit max732x_exit(void)
729{
730	i2c_del_driver(&max732x_driver);
731}
732module_exit(max732x_exit);
733
734MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
735MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
736MODULE_LICENSE("GPL");