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> | |
16 | #include <linux/smp_lock.h> | |
17 | #include <asm/uaccess.h> | |
18 | #include <asm/nvram.h> | |
19 | ||
20 | #define NVRAM_SIZE 8192 | |
21 | ||
22 | static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) | |
23 | { | |
24 | lock_kernel(); | |
25 | switch (origin) { | |
26 | case 1: | |
27 | offset += file->f_pos; | |
28 | break; | |
29 | case 2: | |
30 | offset += NVRAM_SIZE; | |
31 | break; | |
32 | } | |
33 | if (offset < 0) { | |
34 | unlock_kernel(); | |
35 | return -EINVAL; | |
36 | } | |
37 | file->f_pos = offset; | |
38 | unlock_kernel(); | |
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 | ||
79 | static int nvram_ioctl(struct inode *inode, struct file *file, | |
80 | unsigned int cmd, unsigned long arg) | |
81 | { | |
82 | switch(cmd) { | |
83 | case PMAC_NVRAM_GET_OFFSET: | |
84 | { | |
85 | int part, offset; | |
86 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
87 | return -EFAULT; | |
88 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
89 | return -EINVAL; | |
90 | offset = pmac_get_partition(part); | |
91 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
92 | return -EFAULT; | |
93 | break; | |
94 | } | |
95 | ||
96 | default: | |
97 | return -EINVAL; | |
98 | } | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
fa027c2a | 103 | const struct file_operations nvram_fops = { |
1da177e4 LT |
104 | .owner = THIS_MODULE, |
105 | .llseek = nvram_llseek, | |
106 | .read = read_nvram, | |
107 | .write = write_nvram, | |
108 | .ioctl = nvram_ioctl, | |
109 | }; | |
110 | ||
111 | static struct miscdevice nvram_dev = { | |
112 | NVRAM_MINOR, | |
113 | "nvram", | |
114 | &nvram_fops | |
115 | }; | |
116 | ||
117 | int __init nvram_init(void) | |
118 | { | |
119 | printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n", | |
120 | NVRAM_VERSION); | |
121 | return misc_register(&nvram_dev); | |
122 | } | |
123 | ||
124 | void __exit nvram_cleanup(void) | |
125 | { | |
126 | misc_deregister( &nvram_dev ); | |
127 | } | |
128 | ||
129 | module_init(nvram_init); | |
130 | module_exit(nvram_cleanup); | |
131 | MODULE_LICENSE("GPL"); |