1 /*
2 * /dev/nvram driver for Power Macintosh.
3 */
4
5 #define NVRAM_VERSION "1.0"
6
7 #include <linux/module.h>
8
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/fs.h>
12 #include <linux/miscdevice.h>
13 #include <linux/fcntl.h>
14 #include <linux/nvram.h>
15 #include <linux/init.h>
16 #include <asm/uaccess.h>
17 #include <asm/nvram.h>
18
19 #define NVRAM_SIZE 8192
20
21 static long long nvram_llseek(struct file *file, loff_t offset, int origin)
22 {
23 switch (origin) {
24 case 1:
25 offset += file->f_pos;
26 break;
27 case 2:
28 offset += NVRAM_SIZE;
29 break;
30 }
31 if (offset < 0)
32 return -EINVAL;
33 file->f_pos = offset;
34 return file->f_pos;
35 }
36
37 static ssize_t read_nvram(struct file *file, char *buf,
38 size_t count, loff_t *ppos)
39 {
40 unsigned int i;
41 char *p = buf;
42
43 if (verify_area(VERIFY_WRITE, buf, count))
44 return -EFAULT;
45 if (*ppos >= NVRAM_SIZE)
46 return 0;
47 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count)
48 if (__put_user(nvram_read_byte(i), p))
49 return -EFAULT;
50 *ppos = i;
51 return p - buf;
52 }
53
54 static ssize_t write_nvram(struct file *file, const char *buf,
55 size_t count, loff_t *ppos)
56 {
57 unsigned int i;
58 const char *p = buf;
59 char c;
60
61 if (verify_area(VERIFY_READ, buf, count))
62 return -EFAULT;
63 if (*ppos >= NVRAM_SIZE)
64 return 0;
65 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
66 if (__get_user(c, p))
67 return -EFAULT;
68 nvram_write_byte(c, i);
69 }
70 *ppos = i;
71 return p - buf;
72 }
73
74 static int nvram_ioctl(struct inode *inode, struct file *file,
75 unsigned int cmd, unsigned long arg)
76 {
77 switch(cmd) {
78 case PMAC_NVRAM_GET_OFFSET:
79 {
80 int part, offset;
81 if (copy_from_user(&part,(void*)arg,sizeof(part))!=0)
82 return -EFAULT;
83 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
84 return -EINVAL;
85 offset = pmac_get_partition(part);
86 if (copy_to_user((void*)arg,&offset,sizeof(offset))!=0)
87 return -EFAULT;
88 break;
89 }
90
91 default:
92 return -EINVAL;
93 }
94
95 return 0;
96 }
97
98 struct file_operations nvram_fops = {
99 owner: THIS_MODULE,
100 llseek: nvram_llseek,
101 read: read_nvram,
102 write: write_nvram,
103 ioctl: nvram_ioctl,
104 };
105
106 static struct miscdevice nvram_dev = {
107 NVRAM_MINOR,
108 "nvram",
109 &nvram_fops
110 };
111
112 int __init nvram_init(void)
113 {
114 printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n",
115 NVRAM_VERSION);
116 misc_register(&nvram_dev);
117 return 0;
118 }
119
120 void __exit nvram_cleanup(void)
121 {
122 misc_deregister( &nvram_dev );
123 }
124
125 module_init(nvram_init);
126 module_exit(nvram_cleanup);
127
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.