Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Generic /dev/nvram driver for architectures providing some | |
3 | * "generic" hooks, that is : | |
4 | * | |
d331d830 | 5 | * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size |
1da177e4 LT |
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> | |
1da177e4 LT |
22 | #include <asm/uaccess.h> |
23 | #include <asm/nvram.h> | |
e8222502 BH |
24 | #ifdef CONFIG_PPC_PMAC |
25 | #include <asm/machdep.h> | |
26 | #endif | |
1da177e4 LT |
27 | |
28 | #define NVRAM_SIZE 8192 | |
29 | ||
d331d830 MW |
30 | static ssize_t nvram_len; |
31 | ||
1da177e4 LT |
32 | static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) |
33 | { | |
1da177e4 LT |
34 | switch (origin) { |
35 | case 1: | |
36 | offset += file->f_pos; | |
37 | break; | |
38 | case 2: | |
d331d830 | 39 | offset += nvram_len; |
1da177e4 LT |
40 | break; |
41 | } | |
6783b9cd | 42 | if (offset < 0) |
1da177e4 | 43 | return -EINVAL; |
6783b9cd | 44 | |
1da177e4 | 45 | file->f_pos = offset; |
6783b9cd | 46 | |
1da177e4 LT |
47 | return file->f_pos; |
48 | } | |
49 | ||
50 | static ssize_t read_nvram(struct file *file, char __user *buf, | |
51 | size_t count, loff_t *ppos) | |
52 | { | |
53 | unsigned int i; | |
54 | char __user *p = buf; | |
55 | ||
56 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
57 | return -EFAULT; | |
d331d830 | 58 | if (*ppos >= nvram_len) |
1da177e4 | 59 | return 0; |
d331d830 | 60 | for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) |
1da177e4 LT |
61 | if (__put_user(nvram_read_byte(i), p)) |
62 | return -EFAULT; | |
63 | *ppos = i; | |
64 | return p - buf; | |
65 | } | |
66 | ||
67 | static ssize_t write_nvram(struct file *file, const char __user *buf, | |
68 | size_t count, loff_t *ppos) | |
69 | { | |
70 | unsigned int i; | |
71 | const char __user *p = buf; | |
72 | char c; | |
73 | ||
74 | if (!access_ok(VERIFY_READ, buf, count)) | |
75 | return -EFAULT; | |
d331d830 | 76 | if (*ppos >= nvram_len) |
1da177e4 | 77 | return 0; |
d331d830 | 78 | for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) { |
1da177e4 LT |
79 | if (__get_user(c, p)) |
80 | return -EFAULT; | |
81 | nvram_write_byte(c, i); | |
82 | } | |
83 | *ppos = i; | |
84 | return p - buf; | |
85 | } | |
86 | ||
87 | static int nvram_ioctl(struct inode *inode, struct file *file, | |
88 | unsigned int cmd, unsigned long arg) | |
89 | { | |
90 | switch(cmd) { | |
91 | #ifdef CONFIG_PPC_PMAC | |
92 | case OBSOLETE_PMAC_NVRAM_GET_OFFSET: | |
93 | printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); | |
94 | case IOC_NVRAM_GET_OFFSET: { | |
95 | int part, offset; | |
96 | ||
e8222502 | 97 | if (!machine_is(powermac)) |
1da177e4 LT |
98 | return -EINVAL; |
99 | if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) | |
100 | return -EFAULT; | |
101 | if (part < pmac_nvram_OF || part > pmac_nvram_NR) | |
102 | return -EINVAL; | |
103 | offset = pmac_get_partition(part); | |
104 | if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) | |
105 | return -EFAULT; | |
106 | break; | |
107 | } | |
108 | #endif /* CONFIG_PPC_PMAC */ | |
109 | case IOC_NVRAM_SYNC: | |
110 | nvram_sync(); | |
111 | break; | |
112 | default: | |
113 | return -EINVAL; | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
2b8693c0 | 119 | const struct file_operations nvram_fops = { |
1da177e4 LT |
120 | .owner = THIS_MODULE, |
121 | .llseek = nvram_llseek, | |
122 | .read = read_nvram, | |
123 | .write = write_nvram, | |
124 | .ioctl = nvram_ioctl, | |
125 | }; | |
126 | ||
127 | static struct miscdevice nvram_dev = { | |
128 | NVRAM_MINOR, | |
129 | "nvram", | |
130 | &nvram_fops | |
131 | }; | |
132 | ||
133 | int __init nvram_init(void) | |
134 | { | |
d331d830 MW |
135 | int ret = 0; |
136 | ||
cfc53f65 | 137 | printk(KERN_INFO "Generic non-volatile memory driver v%s\n", |
1da177e4 | 138 | NVRAM_VERSION); |
d331d830 MW |
139 | ret = misc_register(&nvram_dev); |
140 | if (ret != 0) | |
141 | goto out; | |
142 | ||
143 | nvram_len = nvram_get_size(); | |
144 | if (nvram_len < 0) | |
145 | nvram_len = NVRAM_SIZE; | |
146 | ||
147 | out: | |
148 | return ret; | |
1da177e4 LT |
149 | } |
150 | ||
151 | void __exit nvram_cleanup(void) | |
152 | { | |
153 | misc_deregister( &nvram_dev ); | |
154 | } | |
155 | ||
156 | module_init(nvram_init); | |
157 | module_exit(nvram_cleanup); | |
158 | MODULE_LICENSE("GPL"); |