GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / acpi / event.c
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
22 ACPI_MODULE_NAME("event");
23
24 /* ACPI notifier chain */
25 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
26
27 int 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 }
38 EXPORT_SYMBOL(acpi_notifier_call_chain);
39
40 int register_acpi_notifier(struct notifier_block *nb)
41 {
42         return blocking_notifier_chain_register(&acpi_chain_head, nb);
43 }
44 EXPORT_SYMBOL(register_acpi_notifier);
45
46 int unregister_acpi_notifier(struct notifier_block *nb)
47 {
48         return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
49 }
50 EXPORT_SYMBOL(unregister_acpi_notifier);
51
52 #ifdef CONFIG_NET
53 static unsigned int acpi_event_seqnum;
54 struct 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 */
62 enum {
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 */
70 enum {
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
81 static const struct genl_multicast_group acpi_event_mcgrps[] = {
82         { .name = ACPI_GENL_MCAST_GROUP_NAME, },
83 };
84
85 static 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
94 int 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
104         /* allocate memory */
105         size = nla_total_size(sizeof(struct acpi_genl_event)) +
106             nla_total_size(0);
107
108         skb = genlmsg_new(size, GFP_ATOMIC);
109         if (!skb)
110                 return -ENOMEM;
111
112         /* add the genetlink message header */
113         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
114                                  &acpi_event_genl_family, 0,
115                                  ACPI_GENL_CMD_EVENT);
116         if (!msg_header) {
117                 nlmsg_free(skb);
118                 return -ENOMEM;
119         }
120
121         /* fill the data */
122         attr =
123             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
124                         sizeof(struct acpi_genl_event));
125         if (!attr) {
126                 nlmsg_free(skb);
127                 return -EINVAL;
128         }
129
130         event = nla_data(attr);
131         memset(event, 0, sizeof(struct acpi_genl_event));
132
133         strcpy(event->device_class, device_class);
134         strcpy(event->bus_id, bus_id);
135         event->type = type;
136         event->data = data;
137
138         /* send multicast genetlink message */
139         genlmsg_end(skb, msg_header);
140
141         genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
142         return 0;
143 }
144
145 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
146
147 static int acpi_event_genetlink_init(void)
148 {
149         return genl_register_family(&acpi_event_genl_family);
150 }
151
152 #else
153 int acpi_bus_generate_netlink_event(const char *device_class,
154                                       const char *bus_id,
155                                       u8 type, int data)
156 {
157         return 0;
158 }
159
160 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
161
162 static int acpi_event_genetlink_init(void)
163 {
164         return -ENODEV;
165 }
166 #endif
167
168 static int __init acpi_event_init(void)
169 {
170         int error = 0;
171
172         if (acpi_disabled)
173                 return 0;
174
175         /* create genetlink for acpi event */
176         error = acpi_event_genetlink_init();
177         if (error)
178                 printk(KERN_WARNING PREFIX
179                        "Failed to create genetlink family for ACPI event\n");
180         return 0;
181 }
182
183 fs_initcall(acpi_event_init);