[ACPI] check acpi_disabled in IPMI
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / event.c
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1da177e4
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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
4be44fcd 16ACPI_MODULE_NAME("event")
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17
18/* Global vars for handling event proc entry */
19static DEFINE_SPINLOCK(acpi_system_event_lock);
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20int event_is_open = 0;
21extern struct list_head acpi_bus_event_list;
22extern wait_queue_head_t acpi_bus_event_queue;
1da177e4 23
4be44fcd 24static int acpi_system_open_event(struct inode *inode, struct file *file)
1da177e4 25{
c65ade4d 26 spin_lock_irq(&acpi_system_event_lock);
1da177e4 27
c65ade4d 28 if (event_is_open)
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29 goto out_busy;
30
31 event_is_open = 1;
32
c65ade4d 33 spin_unlock_irq(&acpi_system_event_lock);
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34 return 0;
35
4be44fcd 36 out_busy:
c65ade4d 37 spin_unlock_irq(&acpi_system_event_lock);
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38 return -EBUSY;
39}
40
41static ssize_t
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42acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
43 loff_t * ppos)
1da177e4 44{
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45 int result = 0;
46 struct acpi_bus_event event;
47 static char str[ACPI_MAX_STRING];
48 static int chars_remaining = 0;
49 static char *ptr;
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50
51 ACPI_FUNCTION_TRACE("acpi_system_read_event");
52
53 if (!chars_remaining) {
54 memset(&event, 0, sizeof(struct acpi_bus_event));
55
56 if ((file->f_flags & O_NONBLOCK)
57 && (list_empty(&acpi_bus_event_list)))
58 return_VALUE(-EAGAIN);
59
60 result = acpi_bus_receive_event(&event);
61 if (result) {
62 return_VALUE(-EIO);
63 }
64
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65 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
66 event.device_class ? event.
67 device_class : "<unknown>",
68 event.bus_id ? event.
69 bus_id : "<unknown>", event.type,
70 event.data);
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71 ptr = str;
72 }
73
74 if (chars_remaining < count) {
75 count = chars_remaining;
76 }
77
78 if (copy_to_user(buffer, ptr, count))
79 return_VALUE(-EFAULT);
80
81 *ppos += count;
82 chars_remaining -= count;
83 ptr += count;
84
85 return_VALUE(count);
86}
87
4be44fcd 88static int acpi_system_close_event(struct inode *inode, struct file *file)
1da177e4 89{
4be44fcd 90 spin_lock_irq(&acpi_system_event_lock);
1da177e4 91 event_is_open = 0;
4be44fcd 92 spin_unlock_irq(&acpi_system_event_lock);
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93 return 0;
94}
95
4be44fcd 96static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
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97{
98 poll_wait(file, &acpi_bus_event_queue, wait);
99 if (!list_empty(&acpi_bus_event_list))
100 return POLLIN | POLLRDNORM;
101 return 0;
102}
103
104static struct file_operations acpi_system_event_ops = {
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105 .open = acpi_system_open_event,
106 .read = acpi_system_read_event,
107 .release = acpi_system_close_event,
108 .poll = acpi_system_poll_event,
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109};
110
111static int __init acpi_event_init(void)
112{
4be44fcd 113 struct proc_dir_entry *entry;
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114 int error = 0;
115
116 ACPI_FUNCTION_TRACE("acpi_event_init");
117
118 if (acpi_disabled)
119 return_VALUE(0);
120
121 /* 'event' [R] */
122 entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
123 if (entry)
124 entry->proc_fops = &acpi_system_event_ops;
125 else {
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126 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
127 "Unable to create '%s' proc fs entry\n",
128 "event"));
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129 error = -EFAULT;
130 }
131 return_VALUE(error);
132}
133
134subsys_initcall(acpi_event_init);