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
159
|
/*
* Generic /dev/nvram driver for architectures providing some
* "generic" hooks, that is :
*
* nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
*
* Note that an additional hook is supported for PowerMac only
* for getting the nvram "partition" informations
*
*/
#define NVRAM_VERSION "1.1"
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <linux/uaccess.h>
#include <asm/nvram.h>
#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#endif
#define NVRAM_SIZE 8192
static DEFINE_MUTEX(nvram_mutex);
static ssize_t nvram_len;
static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
{
return generic_file_llseek_size(file, offset, origin,
MAX_LFS_FILESIZE, nvram_len);
}
static ssize_t read_nvram(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
unsigned int i;
char __user *p = buf;
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
if (*ppos >= nvram_len)
return 0;
for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
if (__put_user(nvram_read_byte(i), p))
return -EFAULT;
*ppos = i;
return p - buf;
}
static ssize_t write_nvram(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
unsigned int i;
const char __user *p = buf;
char c;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
if (*ppos >= nvram_len)
return 0;
for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
if (__get_user(c, p))
return -EFAULT;
nvram_write_byte(c, i);
}
*ppos = i;
return p - buf;
}
static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch(cmd) {
#ifdef CONFIG_PPC_PMAC
case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
case IOC_NVRAM_GET_OFFSET: {
int part, offset;
if (!machine_is(powermac))
return -EINVAL;
if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
return -EFAULT;
if (part < pmac_nvram_OF || part > pmac_nvram_NR)
return -EINVAL;
offset = pmac_get_partition(part);
if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
return -EFAULT;
break;
}
#endif /* CONFIG_PPC_PMAC */
case IOC_NVRAM_SYNC:
nvram_sync();
break;
default:
return -EINVAL;
}
return 0;
}
static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int ret;
mutex_lock(&nvram_mutex);
ret = nvram_ioctl(file, cmd, arg);
mutex_unlock(&nvram_mutex);
return ret;
}
const struct file_operations nvram_fops = {
.owner = THIS_MODULE,
.llseek = nvram_llseek,
.read = read_nvram,
.write = write_nvram,
.unlocked_ioctl = nvram_unlocked_ioctl,
};
static struct miscdevice nvram_dev = {
NVRAM_MINOR,
"nvram",
&nvram_fops
};
int __init nvram_init(void)
{
int ret = 0;
printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
NVRAM_VERSION);
ret = misc_register(&nvram_dev);
if (ret != 0)
goto out;
nvram_len = nvram_get_size();
if (nvram_len < 0)
nvram_len = NVRAM_SIZE;
out:
return ret;
}
void __exit nvram_cleanup(void)
{
misc_deregister( &nvram_dev );
}
module_init(nvram_init);
module_exit(nvram_cleanup);
MODULE_LICENSE("GPL");
|
