1/*
2 * Copyright 2009-2012 Freescale Semiconductor, Inc. All Rights Reserved.
3 *
4 * Author: Wu Guoxing <b39297@freescale.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/i2c.h>
21#include <linux/gpio.h>
22
23#define GPIO_GROUP_NUM 2
24#define GPIO_NUM_PER_GROUP 8
25#define GPIO_NUM (GPIO_GROUP_NUM*GPIO_NUM_PER_GROUP)
26
27struct mc9s08dz60 {
28	struct i2c_client *client;
29	struct gpio_chip chip;
30};
31
32static inline struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)
33{
34	return container_of(gc, struct mc9s08dz60, chip);
35}
36
37
38static void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
39{
40	*reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
41	*bit = offset % GPIO_NUM_PER_GROUP;
42}
43
44static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
45{
46	u8 reg, bit;
47	s32 value;
48	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
49
50	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
51	value = i2c_smbus_read_byte_data(mc9s->client, reg);
52
53	return (value >= 0) ? (value >> bit) & 0x1 : 0;
54}
55
56static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
57{
58	u8 reg, bit;
59	s32 value;
60
61	mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
62	value = i2c_smbus_read_byte_data(mc9s->client, reg);
63	if (value >= 0) {
64		if (val)
65			value |= 1 << bit;
66		else
67			value &= ~(1 << bit);
68
69		return i2c_smbus_write_byte_data(mc9s->client, reg, value);
70	} else
71		return value;
72
73}
74
75
76static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
77{
78	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
79
80	mc9s08dz60_set(mc9s, offset, val);
81}
82
83static int mc9s08dz60_direction_output(struct gpio_chip *gc,
84				       unsigned offset, int val)
85{
86	struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);
87
88	return mc9s08dz60_set(mc9s, offset, val);
89}
90
91static int mc9s08dz60_probe(struct i2c_client *client,
92			    const struct i2c_device_id *id)
93{
94	struct mc9s08dz60 *mc9s;
95
96	mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
97	if (!mc9s)
98		return -ENOMEM;
99
100	mc9s->chip.label = client->name;
101	mc9s->chip.base = -1;
102	mc9s->chip.dev = &client->dev;
103	mc9s->chip.owner = THIS_MODULE;
104	mc9s->chip.ngpio = GPIO_NUM;
105	mc9s->chip.can_sleep = true;
106	mc9s->chip.get = mc9s08dz60_get_value;
107	mc9s->chip.set = mc9s08dz60_set_value;
108	mc9s->chip.direction_output = mc9s08dz60_direction_output;
109	mc9s->client = client;
110	i2c_set_clientdata(client, mc9s);
111
112	return gpiochip_add(&mc9s->chip);
113}
114
115static int mc9s08dz60_remove(struct i2c_client *client)
116{
117	struct mc9s08dz60 *mc9s;
118
119	mc9s = i2c_get_clientdata(client);
120
121	gpiochip_remove(&mc9s->chip);
122	return 0;
123}
124
125static const struct i2c_device_id mc9s08dz60_id[] = {
126	{"mc9s08dz60", 0},
127	{},
128};
129
130MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
131
132static struct i2c_driver mc9s08dz60_i2c_driver = {
133	.driver = {
134		.owner = THIS_MODULE,
135		.name = "mc9s08dz60",
136	},
137	.probe = mc9s08dz60_probe,
138	.remove = mc9s08dz60_remove,
139	.id_table = mc9s08dz60_id,
140};
141
142module_i2c_driver(mc9s08dz60_i2c_driver);
143
144MODULE_AUTHOR("Freescale Semiconductor, Inc. "
145		"Wu Guoxing <b39297@freescale.com>");
146MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
147MODULE_LICENSE("GPL v2");
148