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Commit | Line | Data |
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1da177e4 LT |
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> | |
1da177e4 LT |
16 | #include <asm/uaccess.h> |
17 | #include <asm/nvram.h> | |
18 | ||
19 | #define NVRAM_SIZE 8192 | |
20 | ||
21 | static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) | |
22 | { | |
1da177e4 | 23 | switch (origin) { |
22735068 JB |
24 | case 0: |
25 | break; | |
1da177e4 LT |
26 | case 1: |
27 | offset += file->f_pos; | |
28 | break; | |
29 | case 2: | |
30 | offset += NVRAM_SIZE; | |
31 | break; | |
22735068 JB |
32 | default: |
33 | offset = -1; | |
1da177e4 | 34 | } |
0b048c7a | 35 | if (offset < 0) |
1da177e4 | 36 | return -EINVAL; |
0b048c7a | 37 | |
1da177e4 | 38 | file->f_pos = offset; |
1da177e4 LT |
39 | return file->f_pos; |
40 | } | |
41 | ||
42 | static ssize_t read_nvram(struct file *file, char __user *buf, | |
43 | size_t count, loff_t *ppos) | |
44 | { | |
45 | unsigned int i; | |
46 | char __user *p = buf; | |
47 | ||
48 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
49 | return -EFAULT; | |
50 | if (*ppos >= NVRAM_SIZE) | |
51 | return 0; | |
52 | for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) | |
53 | if (__put_user(nvram_read_byte(i), p)) | |
54 | return -EFAULT; | |
55 | *ppos = i; | |
56 | return p - buf; | |
57 | } | |
58 | ||
59 | static ssize_t write_nvram(struct file *file, const char __user *buf, | |
60 | size_t count, loff_t *ppos) | |
61 | { | |
62 | unsigned int i; | |
63 | const char __user *p = buf; | |
64 | char c; | |
65 | ||
66 | if (!access_ok(VERIFY_READ, buf, count)) | |
67 | return -EFAULT; | |
68 | if (*ppos >= NVRAM_SIZE) | |
69 | return 0; | |
70 | for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) { | |
71 | if (__get_user(c, p)) | |
72 | return -EFAULT; | |
73 | nvram_write_byte(c, i); | |
74 | } | |
75 | *ppos = i; | |
76 | return p - buf; | |
77 | } | |
78 | ||
0b048c7a | 79 | static long nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
80 | { |
81 | switch(cmd) { | |
82 | case PMAC_NVRAM_GET_OFFSET: | |
83 | { | |
84 | int part, offset; | |
85 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
86 | return -EFAULT; | |
87 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
88 | return -EINVAL; | |
89 | offset = pmac_get_partition(part); | |
90 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
91 | return -EFAULT; | |
92 | break; | |
93 | } | |
94 | ||
95 | default: | |
96 | return -EINVAL; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
fa027c2a | 102 | const struct file_operations nvram_fops = { |
1da177e4 LT |
103 | .owner = THIS_MODULE, |
104 | .llseek = nvram_llseek, | |
105 | .read = read_nvram, | |
106 | .write = write_nvram, | |
55929332 | 107 | .unlocked_ioctl = nvram_ioctl, |
1da177e4 LT |
108 | }; |
109 | ||
110 | static struct miscdevice nvram_dev = { | |
111 | NVRAM_MINOR, | |
112 | "nvram", | |
113 | &nvram_fops | |
114 | }; | |
115 | ||
116 | int __init nvram_init(void) | |
117 | { | |
118 | printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n", | |
119 | NVRAM_VERSION); | |
120 | return misc_register(&nvram_dev); | |
121 | } | |
122 | ||
123 | void __exit nvram_cleanup(void) | |
124 | { | |
125 | misc_deregister( &nvram_dev ); | |
126 | } | |
127 | ||
128 | module_init(nvram_init); | |
129 | module_exit(nvram_cleanup); | |
130 | MODULE_LICENSE("GPL"); |