Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Generic /dev/nvram driver for architectures providing some | |
3 | * "generic" hooks, that is : | |
4 | * | |
5 | * nvram_read_byte, nvram_write_byte, nvram_sync | |
6 | * | |
7 | * Note that an additional hook is supported for PowerMac only | |
8 | * for getting the nvram "partition" informations | |
9 | * | |
10 | */ | |
11 | ||
12 | #define NVRAM_VERSION "1.1" | |
13 | ||
14 | #include <linux/module.h> | |
15 | ||
16 | #include <linux/types.h> | |
17 | #include <linux/errno.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/miscdevice.h> | |
20 | #include <linux/fcntl.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/smp_lock.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <asm/nvram.h> | |
e8222502 BH |
25 | #ifdef CONFIG_PPC_PMAC |
26 | #include <asm/machdep.h> | |
27 | #endif | |
1da177e4 LT |
28 | |
29 | #define NVRAM_SIZE 8192 | |
30 | ||
31 | static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) | |
32 | { | |
33 | lock_kernel(); | |
34 | switch (origin) { | |
35 | case 1: | |
36 | offset += file->f_pos; | |
37 | break; | |
38 | case 2: | |
39 | offset += NVRAM_SIZE; | |
40 | break; | |
41 | } | |
42 | if (offset < 0) { | |
43 | unlock_kernel(); | |
44 | return -EINVAL; | |
45 | } | |
46 | file->f_pos = offset; | |
47 | unlock_kernel(); | |
48 | return file->f_pos; | |
49 | } | |
50 | ||
51 | static ssize_t read_nvram(struct file *file, char __user *buf, | |
52 | size_t count, loff_t *ppos) | |
53 | { | |
54 | unsigned int i; | |
55 | char __user *p = buf; | |
56 | ||
57 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
58 | return -EFAULT; | |
59 | if (*ppos >= NVRAM_SIZE) | |
60 | return 0; | |
61 | for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) | |
62 | if (__put_user(nvram_read_byte(i), p)) | |
63 | return -EFAULT; | |
64 | *ppos = i; | |
65 | return p - buf; | |
66 | } | |
67 | ||
68 | static ssize_t write_nvram(struct file *file, const char __user *buf, | |
69 | size_t count, loff_t *ppos) | |
70 | { | |
71 | unsigned int i; | |
72 | const char __user *p = buf; | |
73 | char c; | |
74 | ||
75 | if (!access_ok(VERIFY_READ, buf, count)) | |
76 | return -EFAULT; | |
77 | if (*ppos >= NVRAM_SIZE) | |
78 | return 0; | |
79 | for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) { | |
80 | if (__get_user(c, p)) | |
81 | return -EFAULT; | |
82 | nvram_write_byte(c, i); | |
83 | } | |
84 | *ppos = i; | |
85 | return p - buf; | |
86 | } | |
87 | ||
88 | static int nvram_ioctl(struct inode *inode, struct file *file, | |
89 | unsigned int cmd, unsigned long arg) | |
90 | { | |
91 | switch(cmd) { | |
92 | #ifdef CONFIG_PPC_PMAC | |
93 | case OBSOLETE_PMAC_NVRAM_GET_OFFSET: | |
94 | printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); | |
95 | case IOC_NVRAM_GET_OFFSET: { | |
96 | int part, offset; | |
97 | ||
e8222502 | 98 | if (!machine_is(powermac)) |
1da177e4 LT |
99 | return -EINVAL; |
100 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
101 | return -EFAULT; | |
102 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
103 | return -EINVAL; | |
104 | offset = pmac_get_partition(part); | |
105 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
106 | return -EFAULT; | |
107 | break; | |
108 | } | |
109 | #endif /* CONFIG_PPC_PMAC */ | |
110 | case IOC_NVRAM_SYNC: | |
111 | nvram_sync(); | |
112 | break; | |
113 | default: | |
114 | return -EINVAL; | |
115 | } | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
2b8693c0 | 120 | const struct file_operations nvram_fops = { |
1da177e4 LT |
121 | .owner = THIS_MODULE, |
122 | .llseek = nvram_llseek, | |
123 | .read = read_nvram, | |
124 | .write = write_nvram, | |
125 | .ioctl = nvram_ioctl, | |
126 | }; | |
127 | ||
128 | static struct miscdevice nvram_dev = { | |
129 | NVRAM_MINOR, | |
130 | "nvram", | |
131 | &nvram_fops | |
132 | }; | |
133 | ||
134 | int __init nvram_init(void) | |
135 | { | |
136 | printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n", | |
137 | NVRAM_VERSION); | |
138 | return misc_register(&nvram_dev); | |
139 | } | |
140 | ||
141 | void __exit nvram_cleanup(void) | |
142 | { | |
143 | misc_deregister( &nvram_dev ); | |
144 | } | |
145 | ||
146 | module_init(nvram_init); | |
147 | module_exit(nvram_cleanup); | |
148 | MODULE_LICENSE("GPL"); |