1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <gpio.h>
#define DRVNAME "ar7_gpio"
#define LONGNAME "TI AR7 GPIOs Driver"
MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
MODULE_DESCRIPTION(LONGNAME);
MODULE_LICENSE("GPL");
static int ar7_gpio_major;
static ssize_t ar7_gpio_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
int pin = iminor(file->f_dentry->d_inode);
size_t i;
for (i = 0; i < len; ++i) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
switch (c) {
case '0':
gpio_set_value(pin, 0);
break;
case '1':
gpio_set_value(pin, 1);
break;
case 'd':
case 'D':
ar7_gpio_disable(pin);
break;
case 'e':
case 'E':
ar7_gpio_enable(pin);
break;
case 'i':
case 'I':
case '<':
gpio_direction_input(pin);
break;
case 'o':
case 'O':
case '>':
gpio_direction_output(pin, 0);
break;
default:
return -EINVAL;
}
}
return len;
}
static ssize_t ar7_gpio_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
int pin = iminor(file->f_dentry->d_inode);
int value;
value = gpio_get_value(pin);
if (put_user(value ? '1' : '0', buf))
return -EFAULT;
return 1;
}
static int ar7_gpio_open(struct inode *inode, struct file *file)
{
int m = iminor(inode);
if (m >= (ar7_is_titan() ? TITAN_GPIO_MAX : AR7_GPIO_MAX))
return -EINVAL;
return nonseekable_open(inode, file);
}
static int ar7_gpio_release(struct inode *inode, struct file *file)
{
return 0;
}
static const struct file_operations ar7_gpio_fops = {
.owner = THIS_MODULE,
.write = ar7_gpio_write,
.read = ar7_gpio_read,
.open = ar7_gpio_open,
.release = ar7_gpio_release,
.llseek = no_llseek,
};
static struct platform_device *ar7_gpio_device;
static int __init ar7_gpio_init(void)
{
int rc;
ar7_gpio_device = platform_device_alloc(DRVNAME, -1);
if (!ar7_gpio_device)
return -ENOMEM;
rc = platform_device_add(ar7_gpio_device);
if (rc < 0)
goto out_put;
rc = register_chrdev(ar7_gpio_major, DRVNAME, &ar7_gpio_fops);
if (rc < 0)
goto out_put;
ar7_gpio_major = rc;
rc = 0;
goto out;
out_put:
platform_device_put(ar7_gpio_device);
out:
return rc;
}
static void __exit ar7_gpio_exit(void)
{
unregister_chrdev(ar7_gpio_major, DRVNAME);
platform_device_unregister(ar7_gpio_device);
}
module_init(ar7_gpio_init);
module_exit(ar7_gpio_exit);
|
