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[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 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_NAME          "acpi_event"
136 #define ACPI_GENL_VERSION       0x01
137
138 static struct genl_family acpi_event_genl_family = {
139         .id = GENL_ID_GENERATE,
140         .name = ACPI_GENL_NAME,
141         .version = ACPI_GENL_VERSION,
142         .maxattr = ACPI_GENL_ATTR_MAX,
143 };
144
145 /* .doit: standard command callback */
146 static int acpi_genl_cmd_event(struct sk_buff *skb, struct genl_info *info)
147 {
148         struct acpi_genl_event *event = info->userhdr;
149
150         if (!event)
151                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "ACPI event: NULL\n"));
152
153         return 0;
154 }
155
156 static struct genl_ops acpi_event_genl_ops = {
157         .cmd = ACPI_GENL_CMD_EVENT,
158         .doit = acpi_genl_cmd_event,
159 };
160
161 int acpi_bus_generate_genetlink_event(struct acpi_device *device,
162                                       u8 type, int data)
163 {
164         struct sk_buff *skb;
165         struct nlattr *attr;
166         struct acpi_genl_event *event;
167         void *msg_header;
168         int size;
169         int result;
170
171         /* allocate memory */
172         size = nla_total_size(sizeof(struct acpi_genl_event)) +
173             nla_total_size(0);
174
175         skb = genlmsg_new(size, GFP_ATOMIC);
176         if (!skb)
177                 return -ENOMEM;
178
179         /* add the genetlink message header */
180         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
181                                  &acpi_event_genl_family, 0,
182                                  ACPI_GENL_CMD_EVENT);
183         if (!msg_header) {
184                 nlmsg_free(skb);
185                 return -ENOMEM;
186         }
187
188         /* fill the data */
189         attr =
190             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
191                         sizeof(struct acpi_genl_event));
192         if (!attr) {
193                 nlmsg_free(skb);
194                 return -EINVAL;
195         }
196
197         event = nla_data(attr);
198         if (!event) {
199                 nlmsg_free(skb);
200                 return -EINVAL;
201         }
202
203         memset(event, 0, sizeof(struct acpi_genl_event));
204
205         strcpy(event->device_class, device->pnp.device_class);
206         strcpy(event->bus_id, device->dev.bus_id);
207         event->type = type;
208         event->data = data;
209
210         /* send multicast genetlink message */
211         result = genlmsg_end(skb, msg_header);
212         if (result < 0) {
213                 nlmsg_free(skb);
214                 return result;
215         }
216
217         result =
218             genlmsg_multicast(skb, 0, acpi_event_genl_family.id, GFP_ATOMIC);
219         if (result)
220                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
221                                   "Failed to send a Genetlink message!\n"));
222         return 0;
223 }
224
225 static int acpi_event_genetlink_init(void)
226 {
227         int result;
228
229         result = genl_register_family(&acpi_event_genl_family);
230         if (result)
231                 return result;
232
233         result =
234             genl_register_ops(&acpi_event_genl_family, &acpi_event_genl_ops);
235         if (result)
236                 genl_unregister_family(&acpi_event_genl_family);
237
238         return result;
239 }
240
241 #else
242 int acpi_bus_generate_genetlink_event(struct acpi_device *device, u8 type,
243                                       int data)
244 {
245         return 0;
246 }
247
248 static int acpi_event_genetlink_init(void)
249 {
250         return -ENODEV;
251 }
252 #endif
253
254 static int __init acpi_event_init(void)
255 {
256         struct proc_dir_entry *entry;
257         int error = 0;
258
259         if (acpi_disabled)
260                 return 0;
261
262         /* create genetlink for acpi event */
263         error = acpi_event_genetlink_init();
264         if (error)
265                 printk(KERN_WARNING PREFIX
266                        "Failed to create genetlink family for ACPI event\n");
267
268         /* 'event' [R] */
269         entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
270         if (entry)
271                 entry->proc_fops = &acpi_system_event_ops;
272         else
273                 return -ENODEV;
274
275         return 0;
276 }
277
278 fs_initcall(acpi_event_init);