tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/init.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 void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
33{
34 *reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
35 *bit = offset % GPIO_NUM_PER_GROUP;
36}
37
38static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
39{
40 u8 reg, bit;
41 s32 value;
42 struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
43
44 mc9s_gpio_to_reg_and_bit(offset, ®, &bit);
45 value = i2c_smbus_read_byte_data(mc9s->client, reg);
46
47 return (value >= 0) ? (value >> bit) & 0x1 : 0;
48}
49
50static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
51{
52 u8 reg, bit;
53 s32 value;
54
55 mc9s_gpio_to_reg_and_bit(offset, ®, &bit);
56 value = i2c_smbus_read_byte_data(mc9s->client, reg);
57 if (value >= 0) {
58 if (val)
59 value |= 1 << bit;
60 else
61 value &= ~(1 << bit);
62
63 return i2c_smbus_write_byte_data(mc9s->client, reg, value);
64 } else
65 return value;
66
67}
68
69
70static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
71{
72 struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
73
74 mc9s08dz60_set(mc9s, offset, val);
75}
76
77static int mc9s08dz60_direction_output(struct gpio_chip *gc,
78 unsigned offset, int val)
79{
80 struct mc9s08dz60 *mc9s = gpiochip_get_data(gc);
81
82 return mc9s08dz60_set(mc9s, offset, val);
83}
84
85static int mc9s08dz60_probe(struct i2c_client *client,
86 const struct i2c_device_id *id)
87{
88 struct mc9s08dz60 *mc9s;
89
90 mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
91 if (!mc9s)
92 return -ENOMEM;
93
94 mc9s->chip.label = client->name;
95 mc9s->chip.base = -1;
96 mc9s->chip.parent = &client->dev;
97 mc9s->chip.owner = THIS_MODULE;
98 mc9s->chip.ngpio = GPIO_NUM;
99 mc9s->chip.can_sleep = true;
100 mc9s->chip.get = mc9s08dz60_get_value;
101 mc9s->chip.set = mc9s08dz60_set_value;
102 mc9s->chip.direction_output = mc9s08dz60_direction_output;
103 mc9s->client = client;
104 i2c_set_clientdata(client, mc9s);
105
106 return devm_gpiochip_add_data(&client->dev, &mc9s->chip, mc9s);
107}
108
109static const struct i2c_device_id mc9s08dz60_id[] = {
110 {"mc9s08dz60", 0},
111 {},
112};
113
114static struct i2c_driver mc9s08dz60_i2c_driver = {
115 .driver = {
116 .name = "mc9s08dz60",
117 },
118 .probe = mc9s08dz60_probe,
119 .id_table = mc9s08dz60_id,
120};
121builtin_i2c_driver(mc9s08dz60_i2c_driver);