tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 acpi_system_open_event(struct inode *inode, struct file *file)
25{
26 spin_lock_irq(&acpi_system_event_lock);
27
28 if (event_is_open)
29 goto out_busy;
30
31 event_is_open = 1;
32
33 spin_unlock_irq(&acpi_system_event_lock);
34 return 0;
35
36 out_busy:
37 spin_unlock_irq(&acpi_system_event_lock);
38 return -EBUSY;
39}
40
41static ssize_t
42acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
43 loff_t * ppos)
44{
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;
50
51
52 if (!chars_remaining) {
53 memset(&event, 0, sizeof(struct acpi_bus_event));
54
55 if ((file->f_flags & O_NONBLOCK)
56 && (list_empty(&acpi_bus_event_list)))
57 return -EAGAIN;
58
59 result = acpi_bus_receive_event(&event);
60 if (result)
61 return result;
62
63 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
64 event.device_class ? event.
65 device_class : "<unknown>",
66 event.bus_id ? event.
67 bus_id : "<unknown>", event.type,
68 event.data);
69 ptr = str;
70 }
71
72 if (chars_remaining < count) {
73 count = chars_remaining;
74 }
75
76 if (copy_to_user(buffer, ptr, count))
77 return -EFAULT;
78
79 *ppos += count;
80 chars_remaining -= count;
81 ptr += count;
82
83 return count;
84}
85
86static int acpi_system_close_event(struct inode *inode, struct file *file)
87{
88 spin_lock_irq(&acpi_system_event_lock);
89 event_is_open = 0;
90 spin_unlock_irq(&acpi_system_event_lock);
91 return 0;
92}
93
94static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
95{
96 poll_wait(file, &acpi_bus_event_queue, wait);
97 if (!list_empty(&acpi_bus_event_list))
98 return POLLIN | POLLRDNORM;
99 return 0;
100}
101
102static const struct file_operations acpi_system_event_ops = {
103 .open = acpi_system_open_event,
104 .read = acpi_system_read_event,
105 .release = acpi_system_close_event,
106 .poll = acpi_system_poll_event,
107};
108
109static int __init acpi_event_init(void)
110{
111 struct proc_dir_entry *entry;
112 int error = 0;
113
114
115 if (acpi_disabled)
116 return 0;
117
118 /* 'event' [R] */
119 entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
120 if (entry)
121 entry->proc_fops = &acpi_system_event_ops;
122 else {
123 error = -ENODEV;
124 }
125 return error;
126}
127
128subsys_initcall(acpi_event_init);