Commit | Line | Data |
---|---|---|
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> | |
613655fa | 22 | #include <linux/mutex.h> |
1da177e4 LT |
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 | ||
613655fa | 31 | static DEFINE_MUTEX(nvram_mutex); |
d331d830 MW |
32 | static ssize_t nvram_len; |
33 | ||
1da177e4 LT |
34 | static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) |
35 | { | |
1da177e4 LT |
36 | switch (origin) { |
37 | case 1: | |
38 | offset += file->f_pos; | |
39 | break; | |
40 | case 2: | |
d331d830 | 41 | offset += nvram_len; |
1da177e4 LT |
42 | break; |
43 | } | |
6783b9cd | 44 | if (offset < 0) |
1da177e4 | 45 | return -EINVAL; |
6783b9cd | 46 | |
1da177e4 | 47 | file->f_pos = offset; |
6783b9cd | 48 | |
1da177e4 LT |
49 | return file->f_pos; |
50 | } | |
51 | ||
52 | static ssize_t read_nvram(struct file *file, char __user *buf, | |
53 | size_t count, loff_t *ppos) | |
54 | { | |
55 | unsigned int i; | |
56 | char __user *p = buf; | |
57 | ||
58 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
59 | return -EFAULT; | |
d331d830 | 60 | if (*ppos >= nvram_len) |
1da177e4 | 61 | return 0; |
d331d830 | 62 | for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) |
1da177e4 LT |
63 | if (__put_user(nvram_read_byte(i), p)) |
64 | return -EFAULT; | |
65 | *ppos = i; | |
66 | return p - buf; | |
67 | } | |
68 | ||
69 | static ssize_t write_nvram(struct file *file, const char __user *buf, | |
70 | size_t count, loff_t *ppos) | |
71 | { | |
72 | unsigned int i; | |
73 | const char __user *p = buf; | |
74 | char c; | |
75 | ||
76 | if (!access_ok(VERIFY_READ, buf, count)) | |
77 | return -EFAULT; | |
d331d830 | 78 | if (*ppos >= nvram_len) |
1da177e4 | 79 | return 0; |
d331d830 | 80 | for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) { |
1da177e4 LT |
81 | if (__get_user(c, p)) |
82 | return -EFAULT; | |
83 | nvram_write_byte(c, i); | |
84 | } | |
85 | *ppos = i; | |
86 | return p - buf; | |
87 | } | |
88 | ||
55929332 | 89 | static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
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 | ||
55929332 AB |
120 | static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
121 | { | |
122 | int ret; | |
123 | ||
613655fa | 124 | mutex_lock(&nvram_mutex); |
55929332 | 125 | ret = nvram_ioctl(file, cmd, arg); |
613655fa | 126 | mutex_unlock(&nvram_mutex); |
55929332 AB |
127 | |
128 | return ret; | |
129 | } | |
130 | ||
2b8693c0 | 131 | const struct file_operations nvram_fops = { |
1da177e4 LT |
132 | .owner = THIS_MODULE, |
133 | .llseek = nvram_llseek, | |
134 | .read = read_nvram, | |
135 | .write = write_nvram, | |
55929332 | 136 | .unlocked_ioctl = nvram_unlocked_ioctl, |
1da177e4 LT |
137 | }; |
138 | ||
139 | static struct miscdevice nvram_dev = { | |
140 | NVRAM_MINOR, | |
141 | "nvram", | |
142 | &nvram_fops | |
143 | }; | |
144 | ||
145 | int __init nvram_init(void) | |
146 | { | |
d331d830 MW |
147 | int ret = 0; |
148 | ||
cfc53f65 | 149 | printk(KERN_INFO "Generic non-volatile memory driver v%s\n", |
1da177e4 | 150 | NVRAM_VERSION); |
d331d830 MW |
151 | ret = misc_register(&nvram_dev); |
152 | if (ret != 0) | |
153 | goto out; | |
154 | ||
155 | nvram_len = nvram_get_size(); | |
156 | if (nvram_len < 0) | |
157 | nvram_len = NVRAM_SIZE; | |
158 | ||
159 | out: | |
160 | return ret; | |
1da177e4 LT |
161 | } |
162 | ||
163 | void __exit nvram_cleanup(void) | |
164 | { | |
165 | misc_deregister( &nvram_dev ); | |
166 | } | |
167 | ||
168 | module_init(nvram_init); | |
169 | module_exit(nvram_cleanup); | |
170 | MODULE_LICENSE("GPL"); |