b7b143288c229bf5627ac3f8a3752d2d77394573
[linux-2.6.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/proc_fs.h>
11 #include <linux/init.h>
12 #include <linux/poll.h>
13 #include <acpi/acpi_drivers.h>
14 #include <net/netlink.h>
15 #include <net/genetlink.h>
16
17 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
18 ACPI_MODULE_NAME("event");
19
20 /* Global vars for handling event proc entry */
21 static DEFINE_SPINLOCK(acpi_system_event_lock);
22 int event_is_open = 0;
23 extern struct list_head acpi_bus_event_list;
24 extern wait_queue_head_t acpi_bus_event_queue;
25
26 static int acpi_system_open_event(struct inode *inode, struct file *file)
27 {
28         spin_lock_irq(&acpi_system_event_lock);
29
30         if (event_is_open)
31                 goto out_busy;
32
33         event_is_open = 1;
34
35         spin_unlock_irq(&acpi_system_event_lock);
36         return 0;
37
38       out_busy:
39         spin_unlock_irq(&acpi_system_event_lock);
40         return -EBUSY;
41 }
42
43 static ssize_t
44 acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
45                        loff_t * ppos)
46 {
47         int result = 0;
48         struct acpi_bus_event event;
49         static char str[ACPI_MAX_STRING];
50         static int chars_remaining = 0;
51         static char *ptr;
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 -EAGAIN;
59
60                 result = acpi_bus_receive_event(&event);
61                 if (result)
62                         return result;
63
64                 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
65                                           event.device_class ? event.
66                                           device_class : "<unknown>",
67                                           event.bus_id ? event.
68                                           bus_id : "<unknown>", event.type,
69                                           event.data);
70                 ptr = str;
71         }
72
73         if (chars_remaining < count) {
74                 count = chars_remaining;
75         }
76
77         if (copy_to_user(buffer, ptr, count))
78                 return -EFAULT;
79
80         *ppos += count;
81         chars_remaining -= count;
82         ptr += count;
83
84         return count;
85 }
86
87 static int acpi_system_close_event(struct inode *inode, struct file *file)
88 {
89         spin_lock_irq(&acpi_system_event_lock);
90         event_is_open = 0;
91         spin_unlock_irq(&acpi_system_event_lock);
92         return 0;
93 }
94
95 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
96 {
97         poll_wait(file, &acpi_bus_event_queue, wait);
98         if (!list_empty(&acpi_bus_event_list))
99                 return POLLIN | POLLRDNORM;
100         return 0;
101 }
102
103 static const struct file_operations acpi_system_event_ops = {
104         .open = acpi_system_open_event,
105         .read = acpi_system_read_event,
106         .release = acpi_system_close_event,
107         .poll = acpi_system_poll_event,
108 };
109
110 #ifdef CONFIG_NET
111 static unsigned int acpi_event_seqnum;
112 struct acpi_genl_event {
113         acpi_device_class device_class;
114         char bus_id[15];
115         u32 type;
116         u32 data;
117 };
118
119 /* attributes of acpi_genl_family */
120 enum {
121         ACPI_GENL_ATTR_UNSPEC,
122         ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
123         __ACPI_GENL_ATTR_MAX,
124 };
125 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
126
127 /* commands supported by the acpi_genl_family */
128 enum {
129         ACPI_GENL_CMD_UNSPEC,
130         ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
131         __ACPI_GENL_CMD_MAX,
132 };
133 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
134
135 #define ACPI_GENL_FAMILY_NAME           "acpi_event"
136 #define ACPI_GENL_VERSION               0x01
137 #define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
138
139 static struct genl_family acpi_event_genl_family = {
140         .id = GENL_ID_GENERATE,
141         .name = ACPI_GENL_FAMILY_NAME,
142         .version = ACPI_GENL_VERSION,
143         .maxattr = ACPI_GENL_ATTR_MAX,
144 };
145
146 static struct genl_multicast_group acpi_event_mcgrp = {
147         .name = ACPI_GENL_MCAST_GROUP_NAME,
148 };
149
150 int acpi_bus_generate_netlink_event(const char *device_class,
151                                       const char *bus_id,
152                                       u8 type, int data)
153 {
154         struct sk_buff *skb;
155         struct nlattr *attr;
156         struct acpi_genl_event *event;
157         void *msg_header;
158         int size;
159         int result;
160
161         /* allocate memory */
162         size = nla_total_size(sizeof(struct acpi_genl_event)) +
163             nla_total_size(0);
164
165         skb = genlmsg_new(size, GFP_ATOMIC);
166         if (!skb)
167                 return -ENOMEM;
168
169         /* add the genetlink message header */
170         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
171                                  &acpi_event_genl_family, 0,
172                                  ACPI_GENL_CMD_EVENT);
173         if (!msg_header) {
174                 nlmsg_free(skb);
175                 return -ENOMEM;
176         }
177
178         /* fill the data */
179         attr =
180             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
181                         sizeof(struct acpi_genl_event));
182         if (!attr) {
183                 nlmsg_free(skb);
184                 return -EINVAL;
185         }
186
187         event = nla_data(attr);
188         if (!event) {
189                 nlmsg_free(skb);
190                 return -EINVAL;
191         }
192
193         memset(event, 0, sizeof(struct acpi_genl_event));
194
195         strcpy(event->device_class, device_class);
196         strcpy(event->bus_id, bus_id);
197         event->type = type;
198         event->data = data;
199
200         /* send multicast genetlink message */
201         result = genlmsg_end(skb, msg_header);
202         if (result < 0) {
203                 nlmsg_free(skb);
204                 return result;
205         }
206
207         result =
208             genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
209         if (result)
210                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
211                                   "Failed to send a Genetlink message!\n"));
212         return 0;
213 }
214
215 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
216
217 static int acpi_event_genetlink_init(void)
218 {
219         int result;
220
221         result = genl_register_family(&acpi_event_genl_family);
222         if (result)
223                 return result;
224
225         result = genl_register_mc_group(&acpi_event_genl_family,
226                                         &acpi_event_mcgrp);
227         if (result)
228                 genl_unregister_family(&acpi_event_genl_family);
229
230         return result;
231 }
232
233 #else
234 int acpi_bus_generate_netlink_event(struct acpi_device *device, u8 type,
235                                       int data)
236 {
237         return 0;
238 }
239
240 EXPORT_SYMBOL(acpi_generate_netlink_event);
241
242 static int acpi_event_genetlink_init(void)
243 {
244         return -ENODEV;
245 }
246 #endif
247
248 static int __init acpi_event_init(void)
249 {
250         struct proc_dir_entry *entry;
251         int error = 0;
252
253         if (acpi_disabled)
254                 return 0;
255
256         /* create genetlink for acpi event */
257         error = acpi_event_genetlink_init();
258         if (error)
259                 printk(KERN_WARNING PREFIX
260                        "Failed to create genetlink family for ACPI event\n");
261
262         /* 'event' [R] */
263         entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
264         if (entry)
265                 entry->proc_fops = &acpi_system_event_ops;
266         else
267                 return -ENODEV;
268
269         return 0;
270 }
271
272 fs_initcall(acpi_event_init);