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
|
/* 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"
void nsc_gpio_dump(unsigned index, u32 config)
{
printk(KERN_INFO NAME ": GPIO-%02u: 0x%08lx %s %s %s %s %s %s %s\n",
index, (unsigned long)config,
(config & 1) ? "OE" : "TS", /* output-enabled/tristate */
(config & 2) ? "PP" : "OD", /* push pull / open drain */
(config & 4) ? "PUE" : "PUD", /* pull up enabled/disabled */
(config & 8) ? "LOCKED" : "", /* locked / unlocked */
(config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
(config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */
(config & 64) ? "DEBOUNCE" : ""); /* debounce */
}
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 file-ops routines for both scx200_gpio and pc87360_gpio */
EXPORT_SYMBOL(nsc_gpio_write);
EXPORT_SYMBOL(nsc_gpio_read);
EXPORT_SYMBOL(nsc_gpio_dump);
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");
|
