drivers: video: tegra: Add blacklist for a user TV
[linux-3.10.git] / lib / notifier-error-inject.c
1 #include <linux/module.h>
2
3 #include "notifier-error-inject.h"
4
5 static int debugfs_errno_set(void *data, u64 val)
6 {
7         *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
8         return 0;
9 }
10
11 static int debugfs_errno_get(void *data, u64 *val)
12 {
13         *val = *(int *)data;
14         return 0;
15 }
16
17 DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
18                         "%lld\n");
19
20 static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
21                                 struct dentry *parent, int *value)
22 {
23         return debugfs_create_file(name, mode, parent, value, &fops_errno);
24 }
25
26 static int notifier_err_inject_callback(struct notifier_block *nb,
27                                 unsigned long val, void *p)
28 {
29         int err = 0;
30         struct notifier_err_inject *err_inject =
31                 container_of(nb, struct notifier_err_inject, nb);
32         struct notifier_err_inject_action *action;
33
34         for (action = err_inject->actions; action->name; action++) {
35                 if (action->val == val) {
36                         err = action->error;
37                         break;
38                 }
39         }
40         if (err)
41                 pr_info("Injecting error (%d) to %s\n", err, action->name);
42
43         return notifier_from_errno(err);
44 }
45
46 struct dentry *notifier_err_inject_dir;
47 EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
48
49 struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
50                         struct notifier_err_inject *err_inject, int priority)
51 {
52         struct notifier_err_inject_action *action;
53         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
54         struct dentry *dir;
55         struct dentry *actions_dir;
56
57         err_inject->nb.notifier_call = notifier_err_inject_callback;
58         err_inject->nb.priority = priority;
59
60         dir = debugfs_create_dir(name, parent);
61         if (!dir)
62                 return ERR_PTR(-ENOMEM);
63
64         actions_dir = debugfs_create_dir("actions", dir);
65         if (!actions_dir)
66                 goto fail;
67
68         for (action = err_inject->actions; action->name; action++) {
69                 struct dentry *action_dir;
70
71                 action_dir = debugfs_create_dir(action->name, actions_dir);
72                 if (!action_dir)
73                         goto fail;
74
75                 /*
76                  * Create debugfs r/w file containing action->error. If
77                  * notifier call chain is called with action->val, it will
78                  * fail with the error code
79                  */
80                 if (!debugfs_create_errno("error", mode, action_dir,
81                                         &action->error))
82                         goto fail;
83         }
84         return dir;
85 fail:
86         debugfs_remove_recursive(dir);
87         return ERR_PTR(-ENOMEM);
88 }
89 EXPORT_SYMBOL_GPL(notifier_err_inject_init);
90
91 static int __init err_inject_init(void)
92 {
93         notifier_err_inject_dir =
94                 debugfs_create_dir("notifier-error-inject", NULL);
95
96         if (!notifier_err_inject_dir)
97                 return -ENOMEM;
98
99         return 0;
100 }
101
102 static void __exit err_inject_exit(void)
103 {
104         debugfs_remove_recursive(notifier_err_inject_dir);
105 }
106
107 module_init(err_inject_init);
108 module_exit(err_inject_exit);
109
110 MODULE_DESCRIPTION("Notifier error injection module");
111 MODULE_LICENSE("GPL");
112 MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");