Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[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 <linux/gfp.h>
14 #include <acpi/acpi_drivers.h>
15 #include <net/netlink.h>
16 #include <net/genetlink.h>
17
18 #include "internal.h"
19
20 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
21 ACPI_MODULE_NAME("event");
22
23 #ifdef CONFIG_ACPI_PROC_EVENT
24 /* Global vars for handling event proc entry */
25 static DEFINE_SPINLOCK(acpi_system_event_lock);
26 int event_is_open = 0;
27 extern struct list_head acpi_bus_event_list;
28 extern wait_queue_head_t acpi_bus_event_queue;
29
30 static int acpi_system_open_event(struct inode *inode, struct file *file)
31 {
32         spin_lock_irq(&acpi_system_event_lock);
33
34         if (event_is_open)
35                 goto out_busy;
36
37         event_is_open = 1;
38
39         spin_unlock_irq(&acpi_system_event_lock);
40         return 0;
41
42       out_busy:
43         spin_unlock_irq(&acpi_system_event_lock);
44         return -EBUSY;
45 }
46
47 static ssize_t
48 acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
49                        loff_t * ppos)
50 {
51         int result = 0;
52         struct acpi_bus_event event;
53         static char str[ACPI_MAX_STRING];
54         static int chars_remaining = 0;
55         static char *ptr;
56
57         if (!chars_remaining) {
58                 memset(&event, 0, sizeof(struct acpi_bus_event));
59
60                 if ((file->f_flags & O_NONBLOCK)
61                     && (list_empty(&acpi_bus_event_list)))
62                         return -EAGAIN;
63
64                 result = acpi_bus_receive_event(&event);
65                 if (result)
66                         return result;
67
68                 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
69                                           event.device_class ? event.
70                                           device_class : "<unknown>",
71                                           event.bus_id ? event.
72                                           bus_id : "<unknown>", event.type,
73                                           event.data);
74                 ptr = str;
75         }
76
77         if (chars_remaining < count) {
78                 count = chars_remaining;
79         }
80
81         if (copy_to_user(buffer, ptr, count))
82                 return -EFAULT;
83
84         *ppos += count;
85         chars_remaining -= count;
86         ptr += count;
87
88         return count;
89 }
90
91 static int acpi_system_close_event(struct inode *inode, struct file *file)
92 {
93         spin_lock_irq(&acpi_system_event_lock);
94         event_is_open = 0;
95         spin_unlock_irq(&acpi_system_event_lock);
96         return 0;
97 }
98
99 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
100 {
101         poll_wait(file, &acpi_bus_event_queue, wait);
102         if (!list_empty(&acpi_bus_event_list))
103                 return POLLIN | POLLRDNORM;
104         return 0;
105 }
106
107 static const struct file_operations acpi_system_event_ops = {
108         .owner = THIS_MODULE,
109         .open = acpi_system_open_event,
110         .read = acpi_system_read_event,
111         .release = acpi_system_close_event,
112         .poll = acpi_system_poll_event,
113         .llseek = default_llseek,
114 };
115 #endif  /* CONFIG_ACPI_PROC_EVENT */
116
117 /* ACPI notifier chain */
118 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
119
120 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
121 {
122         struct acpi_bus_event event;
123
124         strcpy(event.device_class, dev->pnp.device_class);
125         strcpy(event.bus_id, dev->pnp.bus_id);
126         event.type = type;
127         event.data = data;
128         return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
129                         == NOTIFY_BAD) ? -EINVAL : 0;
130 }
131 EXPORT_SYMBOL(acpi_notifier_call_chain);
132
133 int register_acpi_notifier(struct notifier_block *nb)
134 {
135         return blocking_notifier_chain_register(&acpi_chain_head, nb);
136 }
137 EXPORT_SYMBOL(register_acpi_notifier);
138
139 int unregister_acpi_notifier(struct notifier_block *nb)
140 {
141         return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
142 }
143 EXPORT_SYMBOL(unregister_acpi_notifier);
144
145 #ifdef CONFIG_NET
146 static unsigned int acpi_event_seqnum;
147 struct acpi_genl_event {
148         acpi_device_class device_class;
149         char bus_id[15];
150         u32 type;
151         u32 data;
152 };
153
154 /* attributes of acpi_genl_family */
155 enum {
156         ACPI_GENL_ATTR_UNSPEC,
157         ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
158         __ACPI_GENL_ATTR_MAX,
159 };
160 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
161
162 /* commands supported by the acpi_genl_family */
163 enum {
164         ACPI_GENL_CMD_UNSPEC,
165         ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
166         __ACPI_GENL_CMD_MAX,
167 };
168 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
169
170 #define ACPI_GENL_FAMILY_NAME           "acpi_event"
171 #define ACPI_GENL_VERSION               0x01
172 #define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
173
174 static struct genl_family acpi_event_genl_family = {
175         .id = GENL_ID_GENERATE,
176         .name = ACPI_GENL_FAMILY_NAME,
177         .version = ACPI_GENL_VERSION,
178         .maxattr = ACPI_GENL_ATTR_MAX,
179 };
180
181 static struct genl_multicast_group acpi_event_mcgrp = {
182         .name = ACPI_GENL_MCAST_GROUP_NAME,
183 };
184
185 int acpi_bus_generate_netlink_event(const char *device_class,
186                                       const char *bus_id,
187                                       u8 type, int data)
188 {
189         struct sk_buff *skb;
190         struct nlattr *attr;
191         struct acpi_genl_event *event;
192         void *msg_header;
193         int size;
194         int result;
195
196         /* allocate memory */
197         size = nla_total_size(sizeof(struct acpi_genl_event)) +
198             nla_total_size(0);
199
200         skb = genlmsg_new(size, GFP_ATOMIC);
201         if (!skb)
202                 return -ENOMEM;
203
204         /* add the genetlink message header */
205         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
206                                  &acpi_event_genl_family, 0,
207                                  ACPI_GENL_CMD_EVENT);
208         if (!msg_header) {
209                 nlmsg_free(skb);
210                 return -ENOMEM;
211         }
212
213         /* fill the data */
214         attr =
215             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
216                         sizeof(struct acpi_genl_event));
217         if (!attr) {
218                 nlmsg_free(skb);
219                 return -EINVAL;
220         }
221
222         event = nla_data(attr);
223         if (!event) {
224                 nlmsg_free(skb);
225                 return -EINVAL;
226         }
227
228         memset(event, 0, sizeof(struct acpi_genl_event));
229
230         strcpy(event->device_class, device_class);
231         strcpy(event->bus_id, bus_id);
232         event->type = type;
233         event->data = data;
234
235         /* send multicast genetlink message */
236         result = genlmsg_end(skb, msg_header);
237         if (result < 0) {
238                 nlmsg_free(skb);
239                 return result;
240         }
241
242         genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
243         return 0;
244 }
245
246 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
247
248 static int acpi_event_genetlink_init(void)
249 {
250         int result;
251
252         result = genl_register_family(&acpi_event_genl_family);
253         if (result)
254                 return result;
255
256         result = genl_register_mc_group(&acpi_event_genl_family,
257                                         &acpi_event_mcgrp);
258         if (result)
259                 genl_unregister_family(&acpi_event_genl_family);
260
261         return result;
262 }
263
264 #else
265 int acpi_bus_generate_netlink_event(const char *device_class,
266                                       const char *bus_id,
267                                       u8 type, int data)
268 {
269         return 0;
270 }
271
272 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
273
274 static int acpi_event_genetlink_init(void)
275 {
276         return -ENODEV;
277 }
278 #endif
279
280 static int __init acpi_event_init(void)
281 {
282 #ifdef CONFIG_ACPI_PROC_EVENT
283         struct proc_dir_entry *entry;
284 #endif
285         int error = 0;
286
287         if (acpi_disabled)
288                 return 0;
289
290         /* create genetlink for acpi event */
291         error = acpi_event_genetlink_init();
292         if (error)
293                 printk(KERN_WARNING PREFIX
294                        "Failed to create genetlink family for ACPI event\n");
295
296 #ifdef CONFIG_ACPI_PROC_EVENT
297         /* 'event' [R] */
298         entry = proc_create("event", S_IRUSR, acpi_root_dir,
299                             &acpi_system_event_ops);
300         if (!entry)
301                 return -ENODEV;
302 #endif
303
304         return 0;
305 }
306
307 fs_initcall(acpi_event_init);