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
27 struct mc9s08dz60 {
28 struct i2c_client *client;
29 struct gpio_chip chip;
30 };
31
to_mc9s08dz60(struct gpio_chip * gc)32 static inline struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)
33 {
34 return container_of(gc, struct mc9s08dz60, chip);
35 }
36
37
mc9s_gpio_to_reg_and_bit(int offset,u8 * reg,u8 * bit)38 static 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
mc9s08dz60_get_value(struct gpio_chip * gc,unsigned offset)44 static 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, ®, &bit);
51 value = i2c_smbus_read_byte_data(mc9s->client, reg);
52
53 return (value >= 0) ? (value >> bit) & 0x1 : 0;
54 }
55
mc9s08dz60_set(struct mc9s08dz60 * mc9s,unsigned offset,int val)56 static 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, ®, &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
mc9s08dz60_set_value(struct gpio_chip * gc,unsigned offset,int val)76 static 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
mc9s08dz60_direction_output(struct gpio_chip * gc,unsigned offset,int val)83 static 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
mc9s08dz60_probe(struct i2c_client * client,const struct i2c_device_id * id)91 static 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 = 1;
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
mc9s08dz60_remove(struct i2c_client * client)115 static int mc9s08dz60_remove(struct i2c_client *client)
116 {
117 struct mc9s08dz60 *mc9s;
118
119 mc9s = i2c_get_clientdata(client);
120
121 return gpiochip_remove(&mc9s->chip);
122 }
123
124 static const struct i2c_device_id mc9s08dz60_id[] = {
125 {"mc9s08dz60", 0},
126 {},
127 };
128
129 MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);
130
131 static struct i2c_driver mc9s08dz60_i2c_driver = {
132 .driver = {
133 .owner = THIS_MODULE,
134 .name = "mc9s08dz60",
135 },
136 .probe = mc9s08dz60_probe,
137 .remove = mc9s08dz60_remove,
138 .id_table = mc9s08dz60_id,
139 };
140
141 module_i2c_driver(mc9s08dz60_i2c_driver);
142
143 MODULE_AUTHOR("Freescale Semiconductor, Inc. "
144 "Wu Guoxing <b39297@freescale.com>");
145 MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
146 MODULE_LICENSE("GPL v2");
147