aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/event.c
blob: ce8d3eec3911df4bd9c59e405f5f49d0b1f3b903 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * event.c - exporting ACPI events via procfs
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 */

#include <linux/spinlock.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <acpi/acpi_drivers.h>

#define _COMPONENT		ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME		("event")

/* Global vars for handling event proc entry */
static DEFINE_SPINLOCK(acpi_system_event_lock);
int				event_is_open = 0;
extern struct list_head		acpi_bus_event_list;
extern wait_queue_head_t	acpi_bus_event_queue;

static int
acpi_system_open_event(struct inode *inode, struct file *file)
{
	spin_lock_irq(&acpi_system_event_lock);

	if (event_is_open)
		goto out_busy;

	event_is_open = 1;

	spin_unlock_irq(&acpi_system_event_lock);
	return 0;

out_busy:
	spin_unlock_irq(&acpi_system_event_lock);
	return -EBUSY;
}

static ssize_t
acpi_system_read_event(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	int			result = 0;
	struct acpi_bus_event	event;
	static char		str[ACPI_MAX_STRING];
	static int		chars_remaining = 0;
	static char		*ptr;


	ACPI_FUNCTION_TRACE("acpi_system_read_event");

	if (!chars_remaining) {
		memset(&event, 0, sizeof(struct acpi_bus_event));

		if ((file->f_flags & O_NONBLOCK)
		    && (list_empty(&acpi_bus_event_list)))
			return_VALUE(-EAGAIN);

		result = acpi_bus_receive_event(&event);
		if (result) {
			return_VALUE(-EIO);
		}

		chars_remaining = sprintf(str, "%s %s %08x %08x\n", 
			event.device_class?event.device_class:"<unknown>",
			event.bus_id?event.bus_id:"<unknown>", 
			event.type, event.data);
		ptr = str;
	}

	if (chars_remaining < count) {
		count = chars_remaining;
	}

	if (copy_to_user(buffer, ptr, count))
		return_VALUE(-EFAULT);

	*ppos += count;
	chars_remaining -= count;
	ptr += count;

	return_VALUE(count);
}

static int
acpi_system_close_event(struct inode *inode, struct file *file)
{
	spin_lock_irq (&acpi_system_event_lock);
	event_is_open = 0;
	spin_unlock_irq (&acpi_system_event_lock);
	return 0;
}

static unsigned int
acpi_system_poll_event(struct file *file, poll_table *wait)
{
	poll_wait(file, &acpi_bus_event_queue, wait);
	if (!list_empty(&acpi_bus_event_list))
		return POLLIN | POLLRDNORM;
	return 0;
}

static struct file_operations acpi_system_event_ops = {
	.open =		acpi_system_open_event,
	.read =		acpi_system_read_event,
	.release =	acpi_system_close_event,
	.poll =		acpi_system_poll_event,
};

static int __init acpi_event_init(void)
{
	struct proc_dir_entry	*entry;
	int error = 0;

	ACPI_FUNCTION_TRACE("acpi_event_init");

	if (acpi_disabled)
		return_VALUE(0);

	/* 'event' [R] */
	entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
	if (entry)
		entry->proc_fops = &acpi_system_event_ops;
	else {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
				  "Unable to create '%s' proc fs entry\n","event" ));
		error = -EFAULT;
	}
	return_VALUE(error);
}

subsys_initcall(acpi_event_init);