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/export.h>
11#include <linux/proc_fs.h>
12#include <linux/init.h>
13#include <linux/poll.h>
14#include <linux/gfp.h>
15#include <linux/acpi.h>
16#include <net/netlink.h>
17#include <net/genetlink.h>
18
19#include "internal.h"
20
21#define _COMPONENT		ACPI_SYSTEM_COMPONENT
22ACPI_MODULE_NAME("event");
23
24/* ACPI notifier chain */
25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
26
27int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
28{
29	struct acpi_bus_event event;
30
31	strcpy(event.device_class, dev->pnp.device_class);
32	strcpy(event.bus_id, dev->pnp.bus_id);
33	event.type = type;
34	event.data = data;
35	return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
36                        == NOTIFY_BAD) ? -EINVAL : 0;
37}
38EXPORT_SYMBOL(acpi_notifier_call_chain);
39
40int register_acpi_notifier(struct notifier_block *nb)
41{
42	return blocking_notifier_chain_register(&acpi_chain_head, nb);
43}
44EXPORT_SYMBOL(register_acpi_notifier);
45
46int unregister_acpi_notifier(struct notifier_block *nb)
47{
48	return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
49}
50EXPORT_SYMBOL(unregister_acpi_notifier);
51
52#ifdef CONFIG_NET
53static unsigned int acpi_event_seqnum;
54struct acpi_genl_event {
55	acpi_device_class device_class;
56	char bus_id[15];
57	u32 type;
58	u32 data;
59};
60
61/* attributes of acpi_genl_family */
62enum {
63	ACPI_GENL_ATTR_UNSPEC,
64	ACPI_GENL_ATTR_EVENT,	/* ACPI event info needed by user space */
65	__ACPI_GENL_ATTR_MAX,
66};
67#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
68
69/* commands supported by the acpi_genl_family */
70enum {
71	ACPI_GENL_CMD_UNSPEC,
72	ACPI_GENL_CMD_EVENT,	/* kernel->user notifications for ACPI events */
73	__ACPI_GENL_CMD_MAX,
74};
75#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
76
77#define ACPI_GENL_FAMILY_NAME		"acpi_event"
78#define ACPI_GENL_VERSION		0x01
79#define ACPI_GENL_MCAST_GROUP_NAME 	"acpi_mc_group"
80
81static const struct genl_multicast_group acpi_event_mcgrps[] = {
82	{ .name = ACPI_GENL_MCAST_GROUP_NAME, },
83};
84
85static struct genl_family acpi_event_genl_family = {
86	.id = GENL_ID_GENERATE,
87	.name = ACPI_GENL_FAMILY_NAME,
88	.version = ACPI_GENL_VERSION,
89	.maxattr = ACPI_GENL_ATTR_MAX,
90	.mcgrps = acpi_event_mcgrps,
91	.n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
92};
93
94int acpi_bus_generate_netlink_event(const char *device_class,
95				      const char *bus_id,
96				      u8 type, int data)
97{
98	struct sk_buff *skb;
99	struct nlattr *attr;
100	struct acpi_genl_event *event;
101	void *msg_header;
102	int size;
103	int result;
104
105	/* allocate memory */
106	size = nla_total_size(sizeof(struct acpi_genl_event)) +
107	    nla_total_size(0);
108
109	skb = genlmsg_new(size, GFP_ATOMIC);
110	if (!skb)
111		return -ENOMEM;
112
113	/* add the genetlink message header */
114	msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
115				 &acpi_event_genl_family, 0,
116				 ACPI_GENL_CMD_EVENT);
117	if (!msg_header) {
118		nlmsg_free(skb);
119		return -ENOMEM;
120	}
121
122	/* fill the data */
123	attr =
124	    nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
125			sizeof(struct acpi_genl_event));
126	if (!attr) {
127		nlmsg_free(skb);
128		return -EINVAL;
129	}
130
131	event = nla_data(attr);
132	memset(event, 0, sizeof(struct acpi_genl_event));
133
134	strcpy(event->device_class, device_class);
135	strcpy(event->bus_id, bus_id);
136	event->type = type;
137	event->data = data;
138
139	/* send multicast genetlink message */
140	result = genlmsg_end(skb, msg_header);
141	if (result < 0) {
142		nlmsg_free(skb);
143		return result;
144	}
145
146	genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
147	return 0;
148}
149
150EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
151
152static int acpi_event_genetlink_init(void)
153{
154	return genl_register_family(&acpi_event_genl_family);
155}
156
157#else
158int acpi_bus_generate_netlink_event(const char *device_class,
159				      const char *bus_id,
160				      u8 type, int data)
161{
162	return 0;
163}
164
165EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
166
167static int acpi_event_genetlink_init(void)
168{
169	return -ENODEV;
170}
171#endif
172
173static int __init acpi_event_init(void)
174{
175	int error = 0;
176
177	if (acpi_disabled)
178		return 0;
179
180	/* create genetlink for acpi event */
181	error = acpi_event_genetlink_init();
182	if (error)
183		printk(KERN_WARNING PREFIX
184		       "Failed to create genetlink family for ACPI event\n");
185	return 0;
186}
187
188fs_initcall(acpi_event_init);
189