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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * event.c - exporting ACPI events via procfs | |
3 | * | |
4 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | |
5 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <linux/spinlock.h> | |
10 | #include <linux/proc_fs.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/poll.h> | |
13 | #include <acpi/acpi_drivers.h> | |
14 | ||
15 | #define _COMPONENT ACPI_SYSTEM_COMPONENT | |
16 | ACPI_MODULE_NAME ("event") | |
17 | ||
18 | /* Global vars for handling event proc entry */ | |
19 | static DEFINE_SPINLOCK(acpi_system_event_lock); | |
20 | int event_is_open = 0; | |
21 | extern struct list_head acpi_bus_event_list; | |
22 | extern wait_queue_head_t acpi_bus_event_queue; | |
23 | ||
24 | static int | |
25 | acpi_system_open_event(struct inode *inode, struct file *file) | |
26 | { | |
27 | spin_lock_irq (&acpi_system_event_lock); | |
28 | ||
29 | if(event_is_open) | |
30 | goto out_busy; | |
31 | ||
32 | event_is_open = 1; | |
33 | ||
34 | spin_unlock_irq (&acpi_system_event_lock); | |
35 | return 0; | |
36 | ||
37 | out_busy: | |
38 | spin_unlock_irq (&acpi_system_event_lock); | |
39 | return -EBUSY; | |
40 | } | |
41 | ||
42 | static ssize_t | |
43 | acpi_system_read_event ( | |
44 | struct file *file, | |
45 | char __user *buffer, | |
46 | size_t count, | |
47 | loff_t *ppos) | |
48 | { | |
49 | int result = 0; | |
50 | struct acpi_bus_event event; | |
51 | static char str[ACPI_MAX_STRING]; | |
52 | static int chars_remaining = 0; | |
53 | static char *ptr; | |
54 | ||
55 | ||
56 | ACPI_FUNCTION_TRACE("acpi_system_read_event"); | |
57 | ||
58 | if (!chars_remaining) { | |
59 | memset(&event, 0, sizeof(struct acpi_bus_event)); | |
60 | ||
61 | if ((file->f_flags & O_NONBLOCK) | |
62 | && (list_empty(&acpi_bus_event_list))) | |
63 | return_VALUE(-EAGAIN); | |
64 | ||
65 | result = acpi_bus_receive_event(&event); | |
66 | if (result) { | |
67 | return_VALUE(-EIO); | |
68 | } | |
69 | ||
70 | chars_remaining = sprintf(str, "%s %s %08x %08x\n", | |
71 | event.device_class?event.device_class:"<unknown>", | |
72 | event.bus_id?event.bus_id:"<unknown>", | |
73 | event.type, event.data); | |
74 | ptr = str; | |
75 | } | |
76 | ||
77 | if (chars_remaining < count) { | |
78 | count = chars_remaining; | |
79 | } | |
80 | ||
81 | if (copy_to_user(buffer, ptr, count)) | |
82 | return_VALUE(-EFAULT); | |
83 | ||
84 | *ppos += count; | |
85 | chars_remaining -= count; | |
86 | ptr += count; | |
87 | ||
88 | return_VALUE(count); | |
89 | } | |
90 | ||
91 | static int | |
92 | acpi_system_close_event(struct inode *inode, struct file *file) | |
93 | { | |
94 | spin_lock_irq (&acpi_system_event_lock); | |
95 | event_is_open = 0; | |
96 | spin_unlock_irq (&acpi_system_event_lock); | |
97 | return 0; | |
98 | } | |
99 | ||
100 | static unsigned int | |
101 | acpi_system_poll_event( | |
102 | struct file *file, | |
103 | poll_table *wait) | |
104 | { | |
105 | poll_wait(file, &acpi_bus_event_queue, wait); | |
106 | if (!list_empty(&acpi_bus_event_list)) | |
107 | return POLLIN | POLLRDNORM; | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static struct file_operations acpi_system_event_ops = { | |
112 | .open = acpi_system_open_event, | |
113 | .read = acpi_system_read_event, | |
114 | .release = acpi_system_close_event, | |
115 | .poll = acpi_system_poll_event, | |
116 | }; | |
117 | ||
118 | static int __init acpi_event_init(void) | |
119 | { | |
120 | struct proc_dir_entry *entry; | |
121 | int error = 0; | |
122 | ||
123 | ACPI_FUNCTION_TRACE("acpi_event_init"); | |
124 | ||
125 | if (acpi_disabled) | |
126 | return_VALUE(0); | |
127 | ||
128 | /* 'event' [R] */ | |
129 | entry = create_proc_entry("event", S_IRUSR, acpi_root_dir); | |
130 | if (entry) | |
131 | entry->proc_fops = &acpi_system_event_ops; | |
132 | else { | |
133 | ACPI_DEBUG_PRINT((ACPI_DB_ERROR, | |
134 | "Unable to create '%s' proc fs entry\n","event" )); | |
135 | error = -EFAULT; | |
136 | } | |
137 | return_VALUE(error); | |
138 | } | |
139 | ||
140 | subsys_initcall(acpi_event_init); |