blob: f0e03e7937e31483540d1a910dd250eb14368dc2 [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) {
Josef Bacik22735062011-07-18 13:21:39 -040024 case 0:
25 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 case 1:
27 offset += file->f_pos;
28 break;
29 case 2:
30 offset += NVRAM_SIZE;
31 break;
Josef Bacik22735062011-07-18 13:21:39 -040032 default:
33 offset = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 }
Thomas Gleixner0b048c72009-10-15 10:28:38 +000035 if (offset < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 return -EINVAL;
Thomas Gleixner0b048c72009-10-15 10:28:38 +000037
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 file->f_pos = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 return file->f_pos;
40}
41
42static 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
59static 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
Thomas Gleixner0b048c72009-10-15 10:28:38 +000079static long nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
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
Arjan van de Venfa027c22007-02-12 00:55:33 -0800102const struct file_operations nvram_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 .owner = THIS_MODULE,
104 .llseek = nvram_llseek,
105 .read = read_nvram,
106 .write = write_nvram,
Arnd Bergmann55929332010-04-27 00:24:05 +0200107 .unlocked_ioctl = nvram_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108};
109
110static struct miscdevice nvram_dev = {
111 NVRAM_MINOR,
112 "nvram",
113 &nvram_fops
114};
115
116int __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
123void __exit nvram_cleanup(void)
124{
125 misc_deregister( &nvram_dev );
126}
127
128module_init(nvram_init);
129module_exit(nvram_cleanup);
130MODULE_LICENSE("GPL");