aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/nvram.c
blob: 30791875fc975176c96b11b43413f9fb548583fc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/*
 * /dev/nvram driver for Power Macintosh.
 */

#define NVRAM_VERSION "1.0"

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/nvram.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>

#define NVRAM_SIZE	8192

static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
{
	lock_kernel();
	switch (origin) {
	case 1:
		offset += file->f_pos;
		break;
	case 2:
		offset += NVRAM_SIZE;
		break;
	}
	if (offset < 0) {
		unlock_kernel();
		return -EINVAL;
	}
	file->f_pos = offset;
	unlock_kernel();
	return file->f_pos;
}

static ssize_t read_nvram(struct file *file, char __user *buf,
			  size_t count, loff_t *ppos)
{
	unsigned int i;
	char __user *p = buf;

	if (!access_ok(VERIFY_WRITE, buf, count))
		return -EFAULT;
	if (*ppos >= NVRAM_SIZE)
		return 0;
	for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count)
		if (__put_user(nvram_read_byte(i), p))
			return -EFAULT;
	*ppos = i;
	return p - buf;
}

static ssize_t write_nvram(struct file *file, const char __user *buf,
			   size_t count, loff_t *ppos)
{
	unsigned int i;
	const char __user *p = buf;
	char c;

	if (!access_ok(VERIFY_READ, buf, count))
		return -EFAULT;
	if (*ppos >= NVRAM_SIZE)
		return 0;
	for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
		if (__get_user(c, p))
			return -EFAULT;
		nvram_write_byte(c, i);
	}
	*ppos = i;
	return p - buf;
}

static int nvram_ioctl(struct inode *inode, struct file *file,
	unsigned int cmd, unsigned long arg)
{
	switch(cmd) {
		case PMAC_NVRAM_GET_OFFSET:
		{
			int part, offset;
			if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
				return -EFAULT;
			if (part < pmac_nvram_OF || part > pmac_nvram_NR)
				return -EINVAL;
			offset = pmac_get_partition(part);
			if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
				return -EFAULT;
			break;
		}

		default:
			return -EINVAL;
	}

	return 0;
}

struct file_operations nvram_fops = {
	.owner		= THIS_MODULE,
	.llseek		= nvram_llseek,
	.read		= read_nvram,
	.write		= write_nvram,
	.ioctl		= nvram_ioctl,
};

static struct miscdevice nvram_dev = {
	NVRAM_MINOR,
	"nvram",
	&nvram_fops
};

int __init nvram_init(void)
{
	printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n",
		NVRAM_VERSION);
	return misc_register(&nvram_dev);
}

void __exit nvram_cleanup(void)
{
        misc_deregister( &nvram_dev );
}

module_init(nvram_init);
module_exit(nvram_cleanup);
MODULE_LICENSE("GPL");