[linux.git] / drivers / gpio / max732x.c

/*
 *  max732x.c - I2C Port Expander with 8/16 I/O
 *
 *  Copyright (C) 2007 Marvell International Ltd.
 *  Copyright (C) 2008 Jack Ren <[email protected]>
 *  Copyright (C) 2008 Eric Miao <[email protected]>
 *
 *  Derived from drivers/gpio/pca953x.c
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/gpio.h>

#include <linux/i2c.h>
#include <linux/i2c/max732x.h>


/*
 * Each port of MAX732x (including MAX7319) falls into one of the
 * following three types:
 *
 *   - Push Pull Output
 *   - Input
 *   - Open Drain I/O
 *
 * designated by 'O', 'I' and 'P' individually according to MAXIM's
 * datasheets.
 *
 * There are two groups of I/O ports, each group usually includes
 * up to 8 I/O ports, and is accessed by a specific I2C address:
 *
 *   - Group A : by I2C address 0b'110xxxx
 *   - Group B : by I2C address 0b'101xxxx
 *
 * where 'xxxx' is decided by the connections of pin AD2/AD0.  The
 * address used also affects the initial state of output signals.
 *
 * Within each group of ports, there are five known combinations of
 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
 * the detailed organization of these ports.
 *
 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
 * and GPIOs from GROUP_A are numbered before those from GROUP_B
 * (if there are two groups).
 *
 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
 * they are not supported by this driver.
 */

#define PORT_NONE	0x0	/* '/' No Port */
#define PORT_OUTPUT	0x1	/* 'O' Push-Pull, Output Only */
#define PORT_INPUT	0x2	/* 'I' Input Only */
#define PORT_OPENDRAIN	0x3	/* 'P' Open-Drain, I/O */

#define IO_4I4O		0x5AA5	/* O7 O6 I5 I4 I3 I2 O1 O0 */
#define IO_4P4O		0x5FF5	/* O7 O6 P5 P4 P3 P2 O1 O0 */
#define IO_8I		0xAAAA	/* I7 I6 I5 I4 I3 I2 I1 I0 */
#define IO_8P		0xFFFF	/* P7 P6 P5 P4 P3 P2 P1 P0 */
#define IO_8O		0x5555	/* O7 O6 O5 O4 O3 O2 O1 O0 */

#define GROUP_A(x)	((x) & 0xffff)	/* I2C Addr: 0b'110xxxx */
#define GROUP_B(x)	((x) << 16)	/* I2C Addr: 0b'101xxxx */

static const struct i2c_device_id max732x_id[] = {
	{ "max7319", GROUP_A(IO_8I) },
	{ "max7320", GROUP_B(IO_8O) },
	{ "max7321", GROUP_A(IO_8P) },
	{ "max7322", GROUP_A(IO_4I4O) },
	{ "max7323", GROUP_A(IO_4P4O) },
	{ "max7324", GROUP_A(IO_8I) | GROUP_B(IO_8O) },
	{ "max7325", GROUP_A(IO_8P) | GROUP_B(IO_8O) },
	{ "max7326", GROUP_A(IO_4I4O) | GROUP_B(IO_8O) },
	{ "max7327", GROUP_A(IO_4P4O) | GROUP_B(IO_8O) },
	{ },
};
MODULE_DEVICE_TABLE(i2c, max732x_id);

struct max732x_chip {
	struct gpio_chip gpio_chip;

	struct i2c_client *client;	/* "main" client */
	struct i2c_client *client_dummy;
	struct i2c_client *client_group_a;
	struct i2c_client *client_group_b;

	unsigned int	mask_group_a;
	unsigned int	dir_input;
	unsigned int	dir_output;

	struct mutex	lock;
	uint8_t		reg_out[2];
};

static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val)
{
	struct i2c_client *client;
	int ret;

	client = group_a ? chip->client_group_a : chip->client_group_b;
	ret = i2c_smbus_write_byte(client, val);
	if (ret < 0) {
		dev_err(&client->dev, "failed writing\n");
		return ret;
	}

	return 0;
}

static int max732x_read(struct max732x_chip *chip, int group_a, uint8_t *val)
{
	struct i2c_client *client;
	int ret;

	client = group_a ? chip->client_group_a : chip->client_group_b;
	ret = i2c_smbus_read_byte(client);
	if (ret < 0) {
		dev_err(&client->dev, "failed reading\n");
		return ret;
	}

	*val = (uint8_t)ret;
	return 0;
}

static inline int is_group_a(struct max732x_chip *chip, unsigned off)
{
	return (1u << off) & chip->mask_group_a;
}

static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
	struct max732x_chip *chip;
	uint8_t reg_val;
	int ret;

	chip = container_of(gc, struct max732x_chip, gpio_chip);

	ret = max732x_read(chip, is_group_a(chip, off), &reg_val);
	if (ret < 0)
		return 0;

	return reg_val & (1u << (off & 0x7));
}

static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
	struct max732x_chip *chip;
	uint8_t reg_out, mask = 1u << (off & 0x7);
	int ret;

	chip = container_of(gc, struct max732x_chip, gpio_chip);

	mutex_lock(&chip->lock);

	reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
	reg_out = (val) ? reg_out | mask : reg_out & ~mask;

	ret = max732x_write(chip, is_group_a(chip, off), reg_out);
	if (ret < 0)
		goto out;

	/* update the shadow register then */
	if (off > 7)
		chip->reg_out[1] = reg_out;
	else
		chip->reg_out[0] = reg_out;
out:
	mutex_unlock(&chip->lock);
}

static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
	struct max732x_chip *chip;
	unsigned int mask = 1u << off;

	chip = container_of(gc, struct max732x_chip, gpio_chip);

	if ((mask & chip->dir_input) == 0) {
		dev_dbg(&chip->client->dev, "%s port %d is output only\n",
			chip->client->name, off);
		return -EACCES;
	}

	return 0;
}

static int max732x_gpio_direction_output(struct gpio_chip *gc,
		unsigned off, int val)
{
	struct max732x_chip *chip;
	unsigned int mask = 1u << off;

	chip = container_of(gc, struct max732x_chip, gpio_chip);

	if ((mask & chip->dir_output) == 0) {
		dev_dbg(&chip->client->dev, "%s port %d is input only\n",
			chip->client->name, off);
		return -EACCES;
	}

	max732x_gpio_set_value(gc, off, val);
	return 0;
}

static int __devinit max732x_setup_gpio(struct max732x_chip *chip,
					const struct i2c_device_id *id,
					unsigned gpio_start)
{
	struct gpio_chip *gc = &chip->gpio_chip;
	uint32_t id_data = id->driver_data;
	int i, port = 0;

	for (i = 0; i < 16; i++, id_data >>= 2) {
		unsigned int mask = 1 << port;

		switch (id_data & 0x3) {
		case PORT_OUTPUT:
			chip->dir_output |= mask;
			break;
		case PORT_INPUT:
			chip->dir_input |= mask;
			break;
		case PORT_OPENDRAIN:
			chip->dir_output |= mask;
			chip->dir_input |= mask;
			break;
		default:
			continue;
		}

		if (i < 8)
			chip->mask_group_a |= mask;
		port++;
	}

	if (chip->dir_input)
		gc->direction_input = max732x_gpio_direction_input;
	if (chip->dir_output) {
		gc->direction_output = max732x_gpio_direction_output;
		gc->set = max732x_gpio_set_value;
	}
	gc->get = max732x_gpio_get_value;
	gc->can_sleep = 1;

	gc->base = gpio_start;
	gc->ngpio = port;
	gc->label = chip->client->name;
	gc->owner = THIS_MODULE;

	return port;
}

static int __devinit max732x_probe(struct i2c_client *client,
				   const struct i2c_device_id *id)
{
	struct max732x_platform_data *pdata;
	struct max732x_chip *chip;
	struct i2c_client *c;
	uint16_t addr_a, addr_b;
	int ret, nr_port;

	pdata = client->dev.platform_data;
	if (pdata == NULL) {
		dev_dbg(&client->dev, "no platform data\n");
		return -EINVAL;
	}

	chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;
	chip->client = client;

	nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);

	addr_a = (client->addr & 0x0f) | 0x60;
	addr_b = (client->addr & 0x0f) | 0x50;

	switch (client->addr & 0x70) {
	case 0x60:
		chip->client_group_a = client;
		if (nr_port > 7) {
			c = i2c_new_dummy(client->adapter, addr_b);
			chip->client_group_b = chip->client_dummy = c;
		}
		break;
	case 0x50:
		chip->client_group_b = client;
		if (nr_port > 7) {
			c = i2c_new_dummy(client->adapter, addr_a);
			chip->client_group_a = chip->client_dummy = c;
		}
		break;
	default:
		dev_err(&client->dev, "invalid I2C address specified %02x\n",
				client->addr);
		ret = -EINVAL;
		goto out_failed;
	}

	mutex_init(&chip->lock);

	max732x_read(chip, is_group_a(chip, 0), &chip->reg_out[0]);
	if (nr_port > 7)
		max732x_read(chip, is_group_a(chip, 8), &chip->reg_out[1]);

	ret = gpiochip_add(&chip->gpio_chip);
	if (ret)
		goto out_failed;

	if (pdata->setup) {
		ret = pdata->setup(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0)
			dev_warn(&client->dev, "setup failed, %d\n", ret);
	}

	i2c_set_clientdata(client, chip);
	return 0;

out_failed:
	kfree(chip);
	return ret;
}

static int __devexit max732x_remove(struct i2c_client *client)
{
	struct max732x_platform_data *pdata = client->dev.platform_data;
	struct max732x_chip *chip = i2c_get_clientdata(client);
	int ret;

	if (pdata->teardown) {
		ret = pdata->teardown(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0) {
			dev_err(&client->dev, "%s failed, %d\n",
					"teardown", ret);
			return ret;
		}
	}

	ret = gpiochip_remove(&chip->gpio_chip);
	if (ret) {
		dev_err(&client->dev, "%s failed, %d\n",
				"gpiochip_remove()", ret);
		return ret;
	}

	/* unregister any dummy i2c_client */
	if (chip->client_dummy)
		i2c_unregister_device(chip->client_dummy);

	kfree(chip);
	return 0;
}

static struct i2c_driver max732x_driver = {
	.driver = {
		.name	= "max732x",
		.owner	= THIS_MODULE,
	},
	.probe		= max732x_probe,
	.remove		= __devexit_p(max732x_remove),
	.id_table	= max732x_id,
};

static int __init max732x_init(void)
{
	return i2c_add_driver(&max732x_driver);
}
/* register after i2c postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(max732x_init);

static void __exit max732x_exit(void)
{
	i2c_del_driver(&max732x_driver);
}
module_exit(max732x_exit);

MODULE_AUTHOR("Eric Miao <[email protected]>");
MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
MODULE_LICENSE("GPL");
Commit	Line	Data
bbcd6d54 EM	1	/*
	2	* max732x.c - I2C Port Expander with 8/16 I/O
	3	*
	4	* Copyright (C) 2007 Marvell International Ltd.
	5	* Copyright (C) 2008 Jack Ren <[email protected]>
	6	* Copyright (C) 2008 Eric Miao <[email protected]>
	7	*
	8	* Derived from drivers/gpio/pca953x.c
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; version 2 of the License.
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/slab.h>
	18	#include <linux/string.h>
	19	#include <linux/gpio.h>
	20
	21	#include <linux/i2c.h>
	22	#include <linux/i2c/max732x.h>
	23
	24
	25	/*
	26	* Each port of MAX732x (including MAX7319) falls into one of the
	27	* following three types:
	28	*
	29	* - Push Pull Output
	30	* - Input
	31	* - Open Drain I/O
	32	*
	33	* designated by 'O', 'I' and 'P' individually according to MAXIM's
	34	* datasheets.
	35	*
	36	* There are two groups of I/O ports, each group usually includes
	37	* up to 8 I/O ports, and is accessed by a specific I2C address:
	38	*
	39	* - Group A : by I2C address 0b'110xxxx
	40	* - Group B : by I2C address 0b'101xxxx
	41	*
	42	* where 'xxxx' is decided by the connections of pin AD2/AD0. The
	43	* address used also affects the initial state of output signals.
	44	*
	45	* Within each group of ports, there are five known combinations of
	46	* I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
	47	* the detailed organization of these ports.
	48	*
	49	* GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
	50	* and GPIOs from GROUP_A are numbered before those from GROUP_B
	51	* (if there are two groups).
	52	*
	53	* NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
	54	* they are not supported by this driver.
	55	*/
	56
	57	#define PORT_NONE 0x0 /* '/' No Port */
	58	#define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */
	59	#define PORT_INPUT 0x2 /* 'I' Input Only */
	60	#define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */
	61
	62	#define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */
	63	#define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */
	64	#define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */
65	#define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */
66	#define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */
67
68	#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
69	#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
70
71	static const struct i2c_device_id max732x_id[] = {
72	{ "max7319", GROUP_A(IO_8I) },
73	{ "max7320", GROUP_B(IO_8O) },
74	{ "max7321", GROUP_A(IO_8P) },
75	{ "max7322", GROUP_A(IO_4I4O) },
76	{ "max7323", GROUP_A(IO_4P4O) },
77	{ "max7324", GROUP_A(IO_8I) \| GROUP_B(IO_8O) },
78	{ "max7325", GROUP_A(IO_8P) \| GROUP_B(IO_8O) },
79	{ "max7326", GROUP_A(IO_4I4O) \| GROUP_B(IO_8O) },
80	{ "max7327", GROUP_A(IO_4P4O) \| GROUP_B(IO_8O) },
81	{ },
82	};
83	MODULE_DEVICE_TABLE(i2c, max732x_id);
84
85	struct max732x_chip {
86	struct gpio_chip gpio_chip;
87
88	struct i2c_client client; / "main" client */
89	struct i2c_client *client_dummy;
90	struct i2c_client *client_group_a;
91	struct i2c_client *client_group_b;
92
93	unsigned int mask_group_a;
94	unsigned int dir_input;
95	unsigned int dir_output;
96
97	struct mutex lock;
98	uint8_t reg_out[2];
99	};
100
101	static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val)
102	{
103	struct i2c_client *client;
104	int ret;
105
106	client = group_a ? chip->client_group_a : chip->client_group_b;
107	ret = i2c_smbus_write_byte(client, val);
108	if (ret < 0) {
109	dev_err(&client->dev, "failed writing\n");
110	return ret;
111	}
112
113	return 0;
114	}
115
116	static int max732x_read(struct max732x_chip chip, int group_a, uint8_t val)
117	{
118	struct i2c_client *client;
119	int ret;
120
121	client = group_a ? chip->client_group_a : chip->client_group_b;
122	ret = i2c_smbus_read_byte(client);
123	if (ret < 0) {
124	dev_err(&client->dev, "failed reading\n");
125	return ret;
126	}
127
128	*val = (uint8_t)ret;
129	return 0;
130	}
131
132	static inline int is_group_a(struct max732x_chip *chip, unsigned off)
133	{
134	return (1u << off) & chip->mask_group_a;
135	}
136
137	static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
138	{
139	struct max732x_chip *chip;
140	uint8_t reg_val;
141	int ret;
142
143	chip = container_of(gc, struct max732x_chip, gpio_chip);
144
145	ret = max732x_read(chip, is_group_a(chip, off), &reg_val);
146	if (ret < 0)
147	return 0;
148
149	return reg_val & (1u << (off & 0x7));
150	}
151
152	static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
153	{
154	struct max732x_chip *chip;
155	uint8_t reg_out, mask = 1u << (off & 0x7);
156	int ret;
157
158	chip = container_of(gc, struct max732x_chip, gpio_chip);
159
160	mutex_lock(&chip->lock);
161
162	reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
163	reg_out = (val) ? reg_out \| mask : reg_out & ~mask;
164
165	ret = max732x_write(chip, is_group_a(chip, off), reg_out);
166	if (ret < 0)
167	goto out;
168
169	/* update the shadow register then */
170	if (off > 7)
171	chip->reg_out[1] = reg_out;
172	else
173	chip->reg_out[0] = reg_out;
174	out:
175	mutex_unlock(&chip->lock);
176	}
177
178	static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
179	{
180	struct max732x_chip *chip;
181	unsigned int mask = 1u << off;
182
183	chip = container_of(gc, struct max732x_chip, gpio_chip);
184
185	if ((mask & chip->dir_input) == 0) {
186	dev_dbg(&chip->client->dev, "%s port %d is output only\n",
187	chip->client->name, off);
188	return -EACCES;
189	}
190
191	return 0;
192	}
193
194	static int max732x_gpio_direction_output(struct gpio_chip *gc,
195	unsigned off, int val)
196	{
197	struct max732x_chip *chip;
198	unsigned int mask = 1u << off;
199
200	chip = container_of(gc, struct max732x_chip, gpio_chip);
201
202	if ((mask & chip->dir_output) == 0) {
203	dev_dbg(&chip->client->dev, "%s port %d is input only\n",
204	chip->client->name, off);
205	return -EACCES;
206	}
207
208	max732x_gpio_set_value(gc, off, val);
209	return 0;
210	}
211
212	static int __devinit max732x_setup_gpio(struct max732x_chip *chip,
213	const struct i2c_device_id *id,
214	unsigned gpio_start)
215	{
216	struct gpio_chip *gc = &chip->gpio_chip;
217	uint32_t id_data = id->driver_data;
218	int i, port = 0;
219
220	for (i = 0; i < 16; i++, id_data >>= 2) {
221	unsigned int mask = 1 << port;
222
223	switch (id_data & 0x3) {
224	case PORT_OUTPUT:
225	chip->dir_output \|= mask;
226	break;
227	case PORT_INPUT:
228	chip->dir_input \|= mask;
229	break;
230	case PORT_OPENDRAIN:
231	chip->dir_output \|= mask;
232	chip->dir_input \|= mask;
233	break;
234	default:
235	continue;
236	}
237
238	if (i < 8)
239	chip->mask_group_a \|= mask;
240	port++;
241	}
242
243	if (chip->dir_input)
244	gc->direction_input = max732x_gpio_direction_input;
245	if (chip->dir_output) {
246	gc->direction_output = max732x_gpio_direction_output;
247	gc->set = max732x_gpio_set_value;
248	}
249	gc->get = max732x_gpio_get_value;
250	gc->can_sleep = 1;
251
252	gc->base = gpio_start;
253	gc->ngpio = port;
254	gc->label = chip->client->name;
255	gc->owner = THIS_MODULE;
256
257	return port;
258	}
259
260	static int __devinit max732x_probe(struct i2c_client *client,
261	const struct i2c_device_id *id)
262	{
263	struct max732x_platform_data *pdata;
264	struct max732x_chip *chip;
265	struct i2c_client *c;
266	uint16_t addr_a, addr_b;
267	int ret, nr_port;
268
269	pdata = client->dev.platform_data;
a342d215 BD	270	if (pdata == NULL) {
	271	dev_dbg(&client->dev, "no platform data\n");
	272	return -EINVAL;
	273	}
bbcd6d54 EM	274
	275	chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
	276	if (chip == NULL)
	277	return -ENOMEM;
	278	chip->client = client;
	279
	280	nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
	281
	282	addr_a = (client->addr & 0x0f) \| 0x60;
	283	addr_b = (client->addr & 0x0f) \| 0x50;
	284
	285	switch (client->addr & 0x70) {
	286	case 0x60:
	287	chip->client_group_a = client;
	288	if (nr_port > 7) {
	289	c = i2c_new_dummy(client->adapter, addr_b);
	290	chip->client_group_b = chip->client_dummy = c;
	291	}
	292	break;
	293	case 0x50:
	294	chip->client_group_b = client;
	295	if (nr_port > 7) {
	296	c = i2c_new_dummy(client->adapter, addr_a);
	297	chip->client_group_a = chip->client_dummy = c;
	298	}
	299	break;
	300	default:
	301	dev_err(&client->dev, "invalid I2C address specified %02x\n",
	302	client->addr);
	303	ret = -EINVAL;
	304	goto out_failed;
	305	}
	306
	307	mutex_init(&chip->lock);
	308
	309	max732x_read(chip, is_group_a(chip, 0), &chip->reg_out[0]);
	310	if (nr_port > 7)
	311	max732x_read(chip, is_group_a(chip, 8), &chip->reg_out[1]);
	312
	313	ret = gpiochip_add(&chip->gpio_chip);
	314	if (ret)
	315	goto out_failed;
	316
	317	if (pdata->setup) {
	318	ret = pdata->setup(client, chip->gpio_chip.base,
	319	chip->gpio_chip.ngpio, pdata->context);
	320	if (ret < 0)
	321	dev_warn(&client->dev, "setup failed, %d\n", ret);
	322	}
	323
	324	i2c_set_clientdata(client, chip);
	325	return 0;
	326
	327	out_failed:
	328	kfree(chip);
	329	return ret;
	330	}
	331
	332	static int __devexit max732x_remove(struct i2c_client *client)
	333	{
	334	struct max732x_platform_data *pdata = client->dev.platform_data;
	335	struct max732x_chip *chip = i2c_get_clientdata(client);
	336	int ret;
	337
338	if (pdata->teardown) {
339	ret = pdata->teardown(client, chip->gpio_chip.base,
340	chip->gpio_chip.ngpio, pdata->context);
341	if (ret < 0) {
342	dev_err(&client->dev, "%s failed, %d\n",
343	"teardown", ret);
344	return ret;
345	}
346	}
347
348	ret = gpiochip_remove(&chip->gpio_chip);
349	if (ret) {
350	dev_err(&client->dev, "%s failed, %d\n",
351	"gpiochip_remove()", ret);
352	return ret;
353	}
354
355	/* unregister any dummy i2c_client */
356	if (chip->client_dummy)
357	i2c_unregister_device(chip->client_dummy);
358
359	kfree(chip);
360	return 0;
361	}
362
363	static struct i2c_driver max732x_driver = {
364	.driver = {
365	.name = "max732x",
366	.owner = THIS_MODULE,
367	},
368	.probe = max732x_probe,
369	.remove = __devexit_p(max732x_remove),
370	.id_table = max732x_id,
371	};
372
373	static int __init max732x_init(void)
374	{
375	return i2c_add_driver(&max732x_driver);
376	}
2f8d1197 DB	377	/* register after i2c postcore initcall and before
	378	* subsys initcalls that may rely on these GPIOs
	379	*/
	380	subsys_initcall(max732x_init);
bbcd6d54 EM	381
	382	static void __exit max732x_exit(void)
	383	{
	384	i2c_del_driver(&max732x_driver);
	385	}
	386	module_exit(max732x_exit);
	387
	388	MODULE_AUTHOR("Eric Miao <[email protected]>");
	389	MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
	390	MODULE_LICENSE("GPL");