Merge commit 'v3.1-rc2' into HEAD
[linux-2.6-block.git] / drivers / macintosh / nvram.c
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 loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
22 {
23         switch (origin) {
24         case 0:
25                 break;
26         case 1:
27                 offset += file->f_pos;
28                 break;
29         case 2:
30                 offset += NVRAM_SIZE;
31                 break;
32         default:
33                 offset = -1;
34         }
35         if (offset < 0)
36                 return -EINVAL;
37
38         file->f_pos = offset;
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 long nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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
102 const struct file_operations nvram_fops = {
103         .owner          = THIS_MODULE,
104         .llseek         = nvram_llseek,
105         .read           = read_nvram,
106         .write          = write_nvram,
107         .unlocked_ioctl = nvram_ioctl,
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");