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
nvram_llseek(struct file * file,loff_t offset,int origin)21 static 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
read_nvram(struct file * file,char * buf,size_t count,loff_t * ppos)37 static ssize_t read_nvram(struct file *file, char *buf,
38 size_t count, loff_t *ppos)
39 {
40 loff_t n = *ppos;
41 unsigned int i = n;
42 char *p = buf;
43
44 if (verify_area(VERIFY_WRITE, buf, count))
45 return -EFAULT;
46 if (i != n || i >= NVRAM_SIZE)
47 return 0;
48 for (; 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
write_nvram(struct file * file,const char * buf,size_t count,loff_t * ppos)55 static ssize_t write_nvram(struct file *file, const char *buf,
56 size_t count, loff_t *ppos)
57 {
58 loff_t n = *ppos;
59 unsigned int i = n;
60 const char *p = buf;
61 char c;
62
63 if (verify_area(VERIFY_READ, buf, count))
64 return -EFAULT;
65 if (i != n || i >= NVRAM_SIZE)
66 return 0;
67 for (; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) {
68 if (__get_user(c, p))
69 return -EFAULT;
70 nvram_write_byte(c, i);
71 }
72 *ppos = i;
73 return p - buf;
74 }
75
nvram_ioctl(struct inode * inode,struct file * file,unsigned int cmd,unsigned long arg)76 static int nvram_ioctl(struct inode *inode, struct file *file,
77 unsigned int cmd, unsigned long arg)
78 {
79 switch(cmd) {
80 case PMAC_NVRAM_GET_OFFSET:
81 {
82 int part, offset;
83 if (copy_from_user(&part,(void*)arg,sizeof(part))!=0)
84 return -EFAULT;
85 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
86 return -EINVAL;
87 offset = pmac_get_partition(part);
88 if (copy_to_user((void*)arg,&offset,sizeof(offset))!=0)
89 return -EFAULT;
90 break;
91 }
92
93 default:
94 return -EINVAL;
95 }
96
97 return 0;
98 }
99
100 struct file_operations nvram_fops = {
101 owner: THIS_MODULE,
102 llseek: nvram_llseek,
103 read: read_nvram,
104 write: write_nvram,
105 ioctl: nvram_ioctl,
106 };
107
108 static struct miscdevice nvram_dev = {
109 NVRAM_MINOR,
110 "nvram",
111 &nvram_fops
112 };
113
nvram_init(void)114 int __init nvram_init(void)
115 {
116 printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n",
117 NVRAM_VERSION);
118 return misc_register(&nvram_dev);
119 }
120
nvram_cleanup(void)121 void __exit nvram_cleanup(void)
122 {
123 misc_deregister( &nvram_dev );
124 }
125
126 module_init(nvram_init);
127 module_exit(nvram_cleanup);
128 MODULE_LICENSE("GPL");
129