blob: c876349c32de5c0d8318db1bcacabf53ef2ed133 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <asm/uaccess.h>
17#include <asm/nvram.h>
18
19#define NVRAM_SIZE 8192
20
21static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
22{
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 switch (origin) {
24 case 1:
25 offset += file->f_pos;
26 break;
27 case 2:
28 offset += NVRAM_SIZE;
29 break;
30 }
Thomas Gleixner0b048c72009-10-15 10:28:38 +000031 if (offset < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 return -EINVAL;
Thomas Gleixner0b048c72009-10-15 10:28:38 +000033
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 file->f_pos = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 return file->f_pos;
36}
37
38static ssize_t read_nvram(struct file *file, char __user *buf,
39 size_t count, loff_t *ppos)
40{
41 unsigned int i;
42 char __user *p = buf;
43
44 if (!access_ok(VERIFY_WRITE, buf, count))
45 return -EFAULT;
46 if (*ppos >= NVRAM_SIZE)
47 return 0;
48 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count)
49 if (__put_user(nvram_read_byte(i), p))
50 return -EFAULT;
51 *ppos = i;
52 return p - buf;
53}
54
55static ssize_t write_nvram(struct file *file, const char __user *buf,
56 size_t count, loff_t *ppos)
57{
58 unsigned int i;
59 const char __user *p = buf;
60 char c;
61
62 if (!access_ok(VERIFY_READ, buf, count))
63 return -EFAULT;
64 if (*ppos >= NVRAM_SIZE)
65 return 0;
66 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
67 if (__get_user(c, p))
68 return -EFAULT;
69 nvram_write_byte(c, i);
70 }
71 *ppos = i;
72 return p - buf;
73}
74
Thomas Gleixner0b048c72009-10-15 10:28:38 +000075static long nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
77 switch(cmd) {
78 case PMAC_NVRAM_GET_OFFSET:
79 {
80 int part, offset;
81 if (copy_from_user(&part, (void __user*)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 __user*)arg, &offset, sizeof(offset)) != 0)
87 return -EFAULT;
88 break;
89 }
90
91 default:
92 return -EINVAL;
93 }
94
95 return 0;
96}
97
Arjan van de Venfa027c22007-02-12 00:55:33 -080098const struct file_operations nvram_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 .owner = THIS_MODULE,
100 .llseek = nvram_llseek,
101 .read = read_nvram,
102 .write = write_nvram,
103 .ioctl = nvram_ioctl,
104};
105
106static struct miscdevice nvram_dev = {
107 NVRAM_MINOR,
108 "nvram",
109 &nvram_fops
110};
111
112int __init nvram_init(void)
113{
114 printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n",
115 NVRAM_VERSION);
116 return misc_register(&nvram_dev);
117}
118
119void __exit nvram_cleanup(void)
120{
121 misc_deregister( &nvram_dev );
122}
123
124module_init(nvram_init);
125module_exit(nvram_cleanup);
126MODULE_LICENSE("GPL");