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