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
21static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
22{
23	switch (origin) {
24	case 1:
25		offset += file->f_pos;
26		break;
27	case 2:
28		offset += NVRAM_SIZE;
29		break;
30	}
31	if (offset < 0)
32		return -EINVAL;
33	file->f_pos = offset;
34	return file->f_pos;
35}
36
37static ssize_t read_nvram(struct file *file, char *buf,
38			  size_t count, loff_t *ppos)
39{
40	unsigned int i;
41	char *p = buf;
42
43	if (verify_area(VERIFY_WRITE, buf, count))
44		return -EFAULT;
45	if (*ppos >= NVRAM_SIZE)
46		return 0;
47	for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count)
48		if (__put_user(nvram_read_byte(i), p))
49			return -EFAULT;
50	*ppos = i;
51	return p - buf;
52}
53
54static ssize_t write_nvram(struct file *file, const char *buf,
55			   size_t count, loff_t *ppos)
56{
57	unsigned int i;
58	const char *p = buf;
59	char c;
60
61	if (verify_area(VERIFY_READ, buf, count))
62		return -EFAULT;
63	if (*ppos >= NVRAM_SIZE)
64		return 0;
65	for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
66		if (__get_user(c, p))
67			return -EFAULT;
68		nvram_write_byte(c, i);
69	}
70	*ppos = i;
71	return p - buf;
72}
73
74static int nvram_ioctl(struct inode *inode, struct file *file,
75	unsigned int cmd, unsigned long arg)
76{
77	switch(cmd) {
78		case PMAC_NVRAM_GET_OFFSET:
79		{
80			int part, offset;
81			if (copy_from_user(&part,(void*)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*)arg,&offset,sizeof(offset))!=0)
87				return -EFAULT;
88			break;
89		}
90
91		default:
92			return -EINVAL;
93	}
94
95	return 0;
96}
97
98struct file_operations nvram_fops = {
99	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	misc_register(&nvram_dev);
117	return 0;
118}
119
120void __exit nvram_cleanup(void)
121{
122        misc_deregister( &nvram_dev );
123}
124
125module_init(nvram_init);
126module_exit(nvram_cleanup);
127MODULE_LICENSE("GPL");
128