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gerrit-public.fairphone.software / kernel / msm / 0c629a69fd8ec7b67566cfc052a9b1c4b927805a / . / drivers / acpi / event.c
blob: 43c49f66a3283b8fa20f7ea796eb9402ef6f4028 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
16ACPI_MODULE_NAME ("event")
17
18/* Global vars for handling event proc entry */
19static DEFINE_SPINLOCK(acpi_system_event_lock);
20int event_is_open = 0;
21extern struct list_head acpi_bus_event_list;
22extern wait_queue_head_t acpi_bus_event_queue;
23
24static int
25acpi_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
37out_busy:
38 spin_unlock_irq (&acpi_system_event_lock);
39 return -EBUSY;
40}
41
42static ssize_t
43acpi_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
91static int
92acpi_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
100static unsigned int
101acpi_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
111static 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
118static 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
140subsys_initcall(acpi_event_init);