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
|
/* linux/drivers/char/nsc_gpio.c
National Semiconductor common GPIO device-file/VFS methods.
Allows a user space process to control the GPIO pins.
Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>
*/
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/nsc_gpio.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#define NAME "nsc_gpio"
ssize_t nsc_gpio_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
unsigned m = iminor(file->f_dentry->d_inode);
struct nsc_gpio_ops *amp = file->private_data;
size_t i;
int err = 0;
for (i = 0; i < len; ++i) {
char c;
if (get_user(c, data + i))
return -EFAULT;
switch (c) {
case '0':
amp->gpio_set(m, 0);
break;
case '1':
amp->gpio_set(m, 1);
break;
case 'O':
printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
amp->gpio_config(m, ~1, 1);
break;
case 'o':
printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
amp->gpio_config(m, ~1, 0);
break;
case 'T':
printk(KERN_INFO NAME ": GPIO%d output is push pull\n",
m);
amp->gpio_config(m, ~2, 2);
break;
case 't':
printk(KERN_INFO NAME ": GPIO%d output is open drain\n",
m);
amp->gpio_config(m, ~2, 0);
break;
case 'P':
printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
amp->gpio_config(m, ~4, 4);
break;
case 'p':
printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
amp->gpio_config(m, ~4, 0);
break;
case 'v':
/* View Current pin settings */
amp->gpio_dump(m);
break;
case '\n':
/* end of settings string, do nothing */
break;
default:
printk(KERN_ERR NAME
": GPIO-%2d bad setting: chr<0x%2x>\n", m,
(int)c);
err++;
}
}
if (err)
return -EINVAL; /* full string handled, report error */
return len;
}
ssize_t nsc_gpio_read(struct file *file, char __user * buf,
size_t len, loff_t * ppos)
{
unsigned m = iminor(file->f_dentry->d_inode);
int value;
struct nsc_gpio_ops *amp = file->private_data;
value = amp->gpio_get(m);
if (put_user(value ? '1' : '0', buf))
return -EFAULT;
return 1;
}
/* common routines for both scx200_gpio and pc87360_gpio */
EXPORT_SYMBOL(nsc_gpio_write);
EXPORT_SYMBOL(nsc_gpio_read);
static int __init nsc_gpio_init(void)
{
printk(KERN_DEBUG NAME " initializing\n");
return 0;
}
static void __exit nsc_gpio_cleanup(void)
{
printk(KERN_DEBUG NAME " cleanup\n");
}
module_init(nsc_gpio_init);
module_exit(nsc_gpio_cleanup);
MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
MODULE_DESCRIPTION("NatSemi GPIO Common Methods");
MODULE_LICENSE("GPL");
|
